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A look at rural ecological revitalization
HUANG Guoqin
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Spatio-temporal variations in vegetation NPP and the driving factors in Taihang Mountain Area
LI Xiaorong, GAO Hui, HAN Lipu, LIU Jintong
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Variation trend and response relationship of temperature, precipitation and runoff in Baiyangdian Lake Basin
GAO Yanchun, WANG Jinfeng, FENG Zhiming
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Intercropping enhances agroecosystem services and functioning: Current knowledge and perspectives
LI Long
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Effects of straw incorporation modes on microbial activity and functional diversity in sandy soil
GU Meiying, TANG Guangmu, GE Chunhui, MA Haigang, ZHANG Zhidong, XU Wanli
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Effect of seedling size on the medicinal properties of Codonopsis pilosula under organic cultivation
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doi: 10.13930/j.cnki.cjea.210188
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doi: 10.12357/cjea.20200807
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doi: 10.12357/cjea.20210583
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doi: 10.13930/j.cnki.cjea.210279
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2021, 29(10): 1649-1657.
doi: 10.13930/j.cnki.cjea.210328
Abstract:
Root exudates are a variety of biochemical substances actively or passively secreted by plant roots that play an important role in mediating material exchange, energy transfer and information exchange in plant rhizosphere microenvironments, as well as in plant responses to environmental stresses. Biotic and abiotic stresses can change the composition and quantity of root exudates and increase the content of defensive compounds in plant root exudates. Plants use different root exudates to resist biotic and abiotic stresses, including releasing toxic substances for direct defense, releasing volatile substances to attract natural enemies, interacting with microorganisms to resist biotic stresses, releasing root exudates with osmotic regulation and antioxidant capacity and coordinating hormone signals to resist abiotic stress. Additionally, root exudate flow increases the concentration of many common metabolites, changing the soil physical and chemical properties and microbial activities, and affecting the physiological and biochemical processes at the soil-plant interface, thereby, directly or indirectly improving plant stress resistance. In this paper, the effects of biotic and abiotic stresses on the composition and quantity of plant root exudates were reviewed, the mechanisms of plant defense against biotic and abiotic stresses mediated by root exudates were summarized, and the aspects needed to be further studied were also suggested, to provide a reference for further research on the adaptive mechanism of plants under stress.
Root exudates are a variety of biochemical substances actively or passively secreted by plant roots that play an important role in mediating material exchange, energy transfer and information exchange in plant rhizosphere microenvironments, as well as in plant responses to environmental stresses. Biotic and abiotic stresses can change the composition and quantity of root exudates and increase the content of defensive compounds in plant root exudates. Plants use different root exudates to resist biotic and abiotic stresses, including releasing toxic substances for direct defense, releasing volatile substances to attract natural enemies, interacting with microorganisms to resist biotic stresses, releasing root exudates with osmotic regulation and antioxidant capacity and coordinating hormone signals to resist abiotic stress. Additionally, root exudate flow increases the concentration of many common metabolites, changing the soil physical and chemical properties and microbial activities, and affecting the physiological and biochemical processes at the soil-plant interface, thereby, directly or indirectly improving plant stress resistance. In this paper, the effects of biotic and abiotic stresses on the composition and quantity of plant root exudates were reviewed, the mechanisms of plant defense against biotic and abiotic stresses mediated by root exudates were summarized, and the aspects needed to be further studied were also suggested, to provide a reference for further research on the adaptive mechanism of plants under stress.
2021, 29(10): 1658-1667.
doi: 10.13930/j.cnki.cjea.210172
Abstract:
With the rapid development of agriculture and animal husbandry, large nitrogen inputs have caused a series of environmental problems. To provide a scientific reference for regional nutrient management, Jiangsu Province, an economically developed region in the Yangtze River Delta, was selected to study the nitrogen flow characteristics in crop-livestock systems from 1998 to 2018 and their environmental effects. The research was based on the NUFER model (NUtrient flows in Food chains, Environment and Resources use, NUFER) and incorporated statistical yearbook data, survey data, and literature data. The nitrogen account balance, nitrogen use efficiency, nitrogen recycling, and loss of the crop-livestock systems in Jiangsu Province were quantitatively analyzed, and the relationships between the economy, resources, and environment of the crop-livestock systems were explored based on a structural equation model. The results showed that from 1998 to 2018, the crop subsystem increased the amount of nitrogen carried by the crop products under the gradual decrease of the total nitrogen imports of the subsystem. Nitrogen carried by the main crops and crop by-products increased from 8.31×105 t to 1.20×106 t. Total nutrient loss also declined. For the livestock-poultry subsystem, nitrogen was mainly introduced via exogenous and local feed; exogenous feed was the main source of nitrogen in the subsystem. The proportion of local feed nitrogen supply increased annually, from 29.32% in 1998 to 44.77% in 2018. From 1998 to 2018, the nitrogen use efficiency of the crop-livestock system increased from 21.39% to 35.00%. The amount of straw to field, local feed, and manure to field increased annually, and the total amount of recycled nitrogen increased from 2.54×105 t to 3.00×105 t. Nitrogen environmental emissions decreased in the past 20 years, and the main sources of loss included soil nitrogen surplus, gas emission loss, water discharge loss, and manure residue. The structural equation model results showed that in the developmental process of the agricultural and animal husbandry systems in Jiangsu Province, economic development and resource reduction promoted improvements in product output and system efficiency. Under the guidance of regional development and policies, crop-livestock systems in Jiangsu Province developed rapidly from 1998 to 2018. The scale of the agricultural and animal husbandry systems had continuously expanded, resource utilization had been relatively efficient, and environmental emissions had gradually decreased. However, there was also a slight imbalance in the development of crop-livestock systems, and there were relatively few combinations of crop-livestock. Future development of the agriculture and animal husbandry systems in Jiangsu Province should focus on coupling the crop and animal husbandry subsystems, moderately expanding the production scale, and balancing the development of agriculture and animal husbandry subsystems to promote local agriculture and animal husbandry.
With the rapid development of agriculture and animal husbandry, large nitrogen inputs have caused a series of environmental problems. To provide a scientific reference for regional nutrient management, Jiangsu Province, an economically developed region in the Yangtze River Delta, was selected to study the nitrogen flow characteristics in crop-livestock systems from 1998 to 2018 and their environmental effects. The research was based on the NUFER model (NUtrient flows in Food chains, Environment and Resources use, NUFER) and incorporated statistical yearbook data, survey data, and literature data. The nitrogen account balance, nitrogen use efficiency, nitrogen recycling, and loss of the crop-livestock systems in Jiangsu Province were quantitatively analyzed, and the relationships between the economy, resources, and environment of the crop-livestock systems were explored based on a structural equation model. The results showed that from 1998 to 2018, the crop subsystem increased the amount of nitrogen carried by the crop products under the gradual decrease of the total nitrogen imports of the subsystem. Nitrogen carried by the main crops and crop by-products increased from 8.31×105 t to 1.20×106 t. Total nutrient loss also declined. For the livestock-poultry subsystem, nitrogen was mainly introduced via exogenous and local feed; exogenous feed was the main source of nitrogen in the subsystem. The proportion of local feed nitrogen supply increased annually, from 29.32% in 1998 to 44.77% in 2018. From 1998 to 2018, the nitrogen use efficiency of the crop-livestock system increased from 21.39% to 35.00%. The amount of straw to field, local feed, and manure to field increased annually, and the total amount of recycled nitrogen increased from 2.54×105 t to 3.00×105 t. Nitrogen environmental emissions decreased in the past 20 years, and the main sources of loss included soil nitrogen surplus, gas emission loss, water discharge loss, and manure residue. The structural equation model results showed that in the developmental process of the agricultural and animal husbandry systems in Jiangsu Province, economic development and resource reduction promoted improvements in product output and system efficiency. Under the guidance of regional development and policies, crop-livestock systems in Jiangsu Province developed rapidly from 1998 to 2018. The scale of the agricultural and animal husbandry systems had continuously expanded, resource utilization had been relatively efficient, and environmental emissions had gradually decreased. However, there was also a slight imbalance in the development of crop-livestock systems, and there were relatively few combinations of crop-livestock. Future development of the agriculture and animal husbandry systems in Jiangsu Province should focus on coupling the crop and animal husbandry subsystems, moderately expanding the production scale, and balancing the development of agriculture and animal husbandry subsystems to promote local agriculture and animal husbandry.
2021, 29(10): 1668-1678.
doi: 10.13930/j.cnki.cjea.210121
Abstract:
Desert vegetation is an important part of arid and semi-arid ecosystems in Xinjiang and plays a key role in the maintenance of ecosystem balance. Timely and accurate monitoring of the temporal and spatial distribution of desert vegetation is important for the sustainable utilization of the resources and ecological restoration. Based on remote sensing technology combined with two Normalized Difference Vegetation Index (NDVI) products (AVHRR-NDVI and MOD13A2-NDVI), the area of desert vegetation in Xinjiang from 1989 to 2017 was estimated. The temporal and spatial characteristics of desert vegetation in three typical river basins (Ulungur River Basin, Aksu River Basin, and Yarkand River Basin) were analyzed, and the relationships between desert vegetation and the climate factors, runoff changes, and policy factors were discussed. The NDVI products were used to calculate the vegetation coverage ( fc), and the distribution and area of desert vegetation were determined according to the threshold of vegetation coverage. Desert vegetation was determined within the fc threshold range of 0.1–0.35, where 0.1–0.25 indicates low-coverage desert vegetation and 0.25–0.35 indicates high-coverage desert vegetation. The transformation between desert vegetation and other vegetation types was calculated using the land use transfer matrix to explore the evolution and transformation of desert vegetation in Xinjiang from 1989 to 2017. The driving factors of desert vegetation evolution in the three typical river basins were analyzed using correlation analysis. The results showed that the total area of desert vegetation in Xinjiang significantly increased from 1989 to 2017 at a rate of 30 900 hm2∙a−1. The area of low-coverage desert vegetation significantly increased at a rate of 32 200 hm2∙a−1; whereas the area of high-coverage desert vegetation did not vary, with a multi-year average value of 2 087 100 hm2. The area of desert vegetation in northern Xinjiang increased slightly, accounting for 67% of the total area of desert vegetation. This was mainly due to an increase in low-coverage desert vegetation. The area of high-coverage desert vegetation in northern Xinjiang slighly decreased. The desert vegetation area in southern Xinjiang significantly increased. During vegetation transformation, 508 500 hm2 of desert vegetation transformed from high to low desert vegetation, 3.4124 million hm2 of non-desert vegetation types transformed into desert vegetation, and 1.9125 million hm2 of desert vegetation transformed into non-desert vegetation types. This study of typical river basins showed that the area of desert vegetation increased with increasing precipitation. Precipitation was the most important factor affecting the evolution of desert vegetation, followed by runoff and policy factors. The influence of air temperature on desert vegetation varied across regions, and the area of desert vegetation near water increased with increasing temperature.
Desert vegetation is an important part of arid and semi-arid ecosystems in Xinjiang and plays a key role in the maintenance of ecosystem balance. Timely and accurate monitoring of the temporal and spatial distribution of desert vegetation is important for the sustainable utilization of the resources and ecological restoration. Based on remote sensing technology combined with two Normalized Difference Vegetation Index (NDVI) products (AVHRR-NDVI and MOD13A2-NDVI), the area of desert vegetation in Xinjiang from 1989 to 2017 was estimated. The temporal and spatial characteristics of desert vegetation in three typical river basins (Ulungur River Basin, Aksu River Basin, and Yarkand River Basin) were analyzed, and the relationships between desert vegetation and the climate factors, runoff changes, and policy factors were discussed. The NDVI products were used to calculate the vegetation coverage ( fc), and the distribution and area of desert vegetation were determined according to the threshold of vegetation coverage. Desert vegetation was determined within the fc threshold range of 0.1–0.35, where 0.1–0.25 indicates low-coverage desert vegetation and 0.25–0.35 indicates high-coverage desert vegetation. The transformation between desert vegetation and other vegetation types was calculated using the land use transfer matrix to explore the evolution and transformation of desert vegetation in Xinjiang from 1989 to 2017. The driving factors of desert vegetation evolution in the three typical river basins were analyzed using correlation analysis. The results showed that the total area of desert vegetation in Xinjiang significantly increased from 1989 to 2017 at a rate of 30 900 hm2∙a−1. The area of low-coverage desert vegetation significantly increased at a rate of 32 200 hm2∙a−1; whereas the area of high-coverage desert vegetation did not vary, with a multi-year average value of 2 087 100 hm2. The area of desert vegetation in northern Xinjiang increased slightly, accounting for 67% of the total area of desert vegetation. This was mainly due to an increase in low-coverage desert vegetation. The area of high-coverage desert vegetation in northern Xinjiang slighly decreased. The desert vegetation area in southern Xinjiang significantly increased. During vegetation transformation, 508 500 hm2 of desert vegetation transformed from high to low desert vegetation, 3.4124 million hm2 of non-desert vegetation types transformed into desert vegetation, and 1.9125 million hm2 of desert vegetation transformed into non-desert vegetation types. This study of typical river basins showed that the area of desert vegetation increased with increasing precipitation. Precipitation was the most important factor affecting the evolution of desert vegetation, followed by runoff and policy factors. The influence of air temperature on desert vegetation varied across regions, and the area of desert vegetation near water increased with increasing temperature.
2021, 29(10): 1679-1691.
doi: 10.13930/j.cnki.cjea.210288
Abstract:
The effects of increased plant density with reduced nitrogen (N) application rate on yield formation and nitrogen use efficiency (NUE) of hybrid rice were studied to provide a theoretical basis for optimum nitrogen fertilizer management and plant density under high temperature with high humidity conditions. Field experiments were conducted in Luzhou City from 2018 to 2019. The high yield and high quality hybrid rice variety ‘Nei6you107’ was grown under six combinations of plant density and N application rate: 1) locally recommended combination with a plant density of 16.5×104 hills∙hm−2 and a N rate of 180 kg∙hm−2 (LDNck); 2) combination of a plant density of 16.5×104 hills∙hm−2 and a reduced N rate by 15% (153 kg∙hm−2, LDN−15%); 3) combination of a plant density of 16.5×104 hills∙hm−2 and a reduced N rate by 30% (126 kg∙hm−2, LDN−30%); 4) combination of a increased plant density by about 27% (21.0×104 hills hm−2) and a reduced N rate by 15% (153 kg∙hm−2, HDN−15%); 5) combination of a increased plant density by about 27% (21.0×104 hills∙hm−2) and a reduced N rate by 30% (126 kg∙hm−2 HDN−30%); and 6) combination of a plant density of 16.5×104 hills∙hm−2 and zero N rate (LDN0). The grain yield, yield components, dry matter, N uptake and NUE were measured. The results showed that the grain yield of hybrid rice was significantly affected by different combinations of plant density and N rate (P<0.01). HDN−15% and HDN−30% produced higher grain yields than LDNck by 4.3%−4.9% and 2.3%−3.6%, respectively. The higher grain yields under HDN−15% and HDN−30% were attributed to improvement in spikelets per panicle, grain filling rate, translocation of dry matter accumulated at heading stage (TDMHD), translocation percentage of dry matter accumulated at heading stage (TPDMHD), contribution percentage of pre-anthesis dry matter translocation to grain yield (CPDMTGHD) and harvest index. The LDN−15% and LDN−30% had 2.3%−2.5% and 4.8%−5.0% lower grain yield than LDNck, respectively. The yield gap between LDN−15%, LDN−30% and LDNck was attributed to the difference in effective panicles, total dry matter, dry matter accumulation from heading to maturity, and contribution percentage of dry matter accumulation from heading to maturity stage to grain yield (CPDMGHD-MA). The HDN−15% and HDN−30% had lower nitrogen accumulation from heading to maturity and total N uptake than LDNck, whereas the translocation of N accumulated at heading stage (NTGNHD), translocation percentage of N accumulated at heading stage (TPNHD), contribution percentage of pre-anthesis N accumulation translocation to grain N accumulation (CPNTGNHD), N use efficiency for biomass production (NUEBP), N use efficiency for grain production (NUEGP) and N harvest index under HDN−15% and HDN−30% were higher than those under LDNck. Consequently, HDN−15% and HDN−30% had lower N requirements to produce 100 kg of grain (NRPG) than LDNck by 6.8%−8.4% and 9.0%−9.9%, respectively. HDN−15% enhanced the agronomic efficiency of applied N (AEN) by 36.7%−37.4%, partial factor productivity of applied N (PFPN) by 22.8%−23.5% and recovery efficiency of applied N (REN) by 5.6%−12.0% over LDNck. The HDN−30% produced higher AEN, PFPN and REN than LDNck by 55.5%−60.4%, 46.3%−48.2% and 17.0%−20.0%, respectively. The rational combination of plant density and N rate can improve panicle number per unit area, grain filling, TDMHD, TPDMHD, NTGNHD, TPNHD and harvest index, which further increasing the grain yield and NUE. The optimum combination is plant density of 21.0×104 hills∙hm−2 plus N rate of 126−153 kg∙hm−2 in high temperature with high humidity condition.
The effects of increased plant density with reduced nitrogen (N) application rate on yield formation and nitrogen use efficiency (NUE) of hybrid rice were studied to provide a theoretical basis for optimum nitrogen fertilizer management and plant density under high temperature with high humidity conditions. Field experiments were conducted in Luzhou City from 2018 to 2019. The high yield and high quality hybrid rice variety ‘Nei6you107’ was grown under six combinations of plant density and N application rate: 1) locally recommended combination with a plant density of 16.5×104 hills∙hm−2 and a N rate of 180 kg∙hm−2 (LDNck); 2) combination of a plant density of 16.5×104 hills∙hm−2 and a reduced N rate by 15% (153 kg∙hm−2, LDN−15%); 3) combination of a plant density of 16.5×104 hills∙hm−2 and a reduced N rate by 30% (126 kg∙hm−2, LDN−30%); 4) combination of a increased plant density by about 27% (21.0×104 hills hm−2) and a reduced N rate by 15% (153 kg∙hm−2, HDN−15%); 5) combination of a increased plant density by about 27% (21.0×104 hills∙hm−2) and a reduced N rate by 30% (126 kg∙hm−2 HDN−30%); and 6) combination of a plant density of 16.5×104 hills∙hm−2 and zero N rate (LDN0). The grain yield, yield components, dry matter, N uptake and NUE were measured. The results showed that the grain yield of hybrid rice was significantly affected by different combinations of plant density and N rate (P<0.01). HDN−15% and HDN−30% produced higher grain yields than LDNck by 4.3%−4.9% and 2.3%−3.6%, respectively. The higher grain yields under HDN−15% and HDN−30% were attributed to improvement in spikelets per panicle, grain filling rate, translocation of dry matter accumulated at heading stage (TDMHD), translocation percentage of dry matter accumulated at heading stage (TPDMHD), contribution percentage of pre-anthesis dry matter translocation to grain yield (CPDMTGHD) and harvest index. The LDN−15% and LDN−30% had 2.3%−2.5% and 4.8%−5.0% lower grain yield than LDNck, respectively. The yield gap between LDN−15%, LDN−30% and LDNck was attributed to the difference in effective panicles, total dry matter, dry matter accumulation from heading to maturity, and contribution percentage of dry matter accumulation from heading to maturity stage to grain yield (CPDMGHD-MA). The HDN−15% and HDN−30% had lower nitrogen accumulation from heading to maturity and total N uptake than LDNck, whereas the translocation of N accumulated at heading stage (NTGNHD), translocation percentage of N accumulated at heading stage (TPNHD), contribution percentage of pre-anthesis N accumulation translocation to grain N accumulation (CPNTGNHD), N use efficiency for biomass production (NUEBP), N use efficiency for grain production (NUEGP) and N harvest index under HDN−15% and HDN−30% were higher than those under LDNck. Consequently, HDN−15% and HDN−30% had lower N requirements to produce 100 kg of grain (NRPG) than LDNck by 6.8%−8.4% and 9.0%−9.9%, respectively. HDN−15% enhanced the agronomic efficiency of applied N (AEN) by 36.7%−37.4%, partial factor productivity of applied N (PFPN) by 22.8%−23.5% and recovery efficiency of applied N (REN) by 5.6%−12.0% over LDNck. The HDN−30% produced higher AEN, PFPN and REN than LDNck by 55.5%−60.4%, 46.3%−48.2% and 17.0%−20.0%, respectively. The rational combination of plant density and N rate can improve panicle number per unit area, grain filling, TDMHD, TPDMHD, NTGNHD, TPNHD and harvest index, which further increasing the grain yield and NUE. The optimum combination is plant density of 21.0×104 hills∙hm−2 plus N rate of 126−153 kg∙hm−2 in high temperature with high humidity condition.
2021, 29(10): 1692-1703.
doi: 10.13930/j.cnki.cjea.210148
Abstract:
Free-living nitrogen fixation (FLNF) by diazotrophs is an important nitrogen (N) source in terrestrial ecosystems and may reprensent a viable solution to environmental pollution caused by N over-fertilization. Studying the impact of different fertilizer regimes in highland barley fields on the diazotrophic community profiles and potential N fixation rates (PNFR) may provide scientific fertilization strategies and a theoretical basis for agricultural green development in the Tibetan Plateau. Here, quantitative PCR, high-throughput sequencing and 15N labeling methods were used to better understand the impact of different fertilizer regimes on the abundance and composition of diazotrophs as well as the potential N fixation rates in highland barley fields on the Tibetan Plateau. The experiment included five treatments: a control without fertilizer (CK); N, phosphorus (P) and potassium (K) mineral fertilzers (F); manure fertilizer (M); mineral NPK fertilizers plus manure (FM); and mineral NPK fertilizer plus straw (FS). The results showed that: 1) compared with the CK and F treatments, the M, FM and FS treatments significantly (P<0.05) increased the contents of soil organic carbon (C) and total N. Moreover, the ammonium nitrogen (NH4+-N) content was significantly (P<0.05) higher in the FM treatment than in the other treatments. The highest contents of organic C, total N, nitrate N (NO3−-N), available P and available K were observed in the M treatment, and their contents were significantly (P<0.05) higher than those in the other treatments. 2) The PNFR ranged from 2.63 to 4.07 μg∙kg−1∙d−1 under different fertilizer treatments. Fertilization, especially the application of organic fertilizers (sheep manure or straw), reduced the PNFR, and the inhibitory effect of straw on PNFR was higher than that of sheep manure. The soil NH4+-N content was the main factor affecting PNFR. 3) The M and FM treatments significantly (P<0.05) increased diazotrophic abundance, while the opposite was observed for the F and FS treatments. The total N content was the key factor affecting diazotrophic abundance. 4) Different fertilizer patterns significantly changed the diazotrophic composition, and the similarities in the diazotrophic compositions among different fertilizer regimes fell into three major categories: no fertilization (CK), organic fertilization (M), and chemical fertilization (F, FM, FS). Available P was the key factor regulating diazotrophic composition, followed by pH and C/N. In conclusion, the M treatment was the optimal fertilizer practice to improve soil fertility, increase diazotrophic abundance and reduce PNFR decline in highland barley fields on the Tibetan Plateau.
Free-living nitrogen fixation (FLNF) by diazotrophs is an important nitrogen (N) source in terrestrial ecosystems and may reprensent a viable solution to environmental pollution caused by N over-fertilization. Studying the impact of different fertilizer regimes in highland barley fields on the diazotrophic community profiles and potential N fixation rates (PNFR) may provide scientific fertilization strategies and a theoretical basis for agricultural green development in the Tibetan Plateau. Here, quantitative PCR, high-throughput sequencing and 15N labeling methods were used to better understand the impact of different fertilizer regimes on the abundance and composition of diazotrophs as well as the potential N fixation rates in highland barley fields on the Tibetan Plateau. The experiment included five treatments: a control without fertilizer (CK); N, phosphorus (P) and potassium (K) mineral fertilzers (F); manure fertilizer (M); mineral NPK fertilizers plus manure (FM); and mineral NPK fertilizer plus straw (FS). The results showed that: 1) compared with the CK and F treatments, the M, FM and FS treatments significantly (P<0.05) increased the contents of soil organic carbon (C) and total N. Moreover, the ammonium nitrogen (NH4+-N) content was significantly (P<0.05) higher in the FM treatment than in the other treatments. The highest contents of organic C, total N, nitrate N (NO3−-N), available P and available K were observed in the M treatment, and their contents were significantly (P<0.05) higher than those in the other treatments. 2) The PNFR ranged from 2.63 to 4.07 μg∙kg−1∙d−1 under different fertilizer treatments. Fertilization, especially the application of organic fertilizers (sheep manure or straw), reduced the PNFR, and the inhibitory effect of straw on PNFR was higher than that of sheep manure. The soil NH4+-N content was the main factor affecting PNFR. 3) The M and FM treatments significantly (P<0.05) increased diazotrophic abundance, while the opposite was observed for the F and FS treatments. The total N content was the key factor affecting diazotrophic abundance. 4) Different fertilizer patterns significantly changed the diazotrophic composition, and the similarities in the diazotrophic compositions among different fertilizer regimes fell into three major categories: no fertilization (CK), organic fertilization (M), and chemical fertilization (F, FM, FS). Available P was the key factor regulating diazotrophic composition, followed by pH and C/N. In conclusion, the M treatment was the optimal fertilizer practice to improve soil fertility, increase diazotrophic abundance and reduce PNFR decline in highland barley fields on the Tibetan Plateau.
2021, 29(10): 1704-1711.
doi: 10.13930/j.cnki.cjea.210151
Abstract:
The study of mechanical grain harvesting quality and its influential factors is significant for popularizing mechanical maize harvesting technology in Shanxi Province and enhancing the core competitiveness of the maize industry. To study the influence of harvest time on the quality and yield of maize mechanically grain harvested, five maize varieties suitable for mechanical harvest were harvested at six times (Septmber 24th, and October 1st, 8th, 15th, 22th and 29th) by the same harvester and driver. The grain moisture content, broken rate, impurity rate, as well as ear loss rate, grain loss rate, total loss rate and yield of maize were investigated. The results were as follows: first, the grain moisture content declined gradually with a delayed harvest time. With a delayed harvest time, the grain broken rate and loss rate decreased rapidly in the early period but was stable and slightly increased in the later period. Furthermore, with a delayed harvest time, the impurity rate declined gradually and tended to be stable at the end. Finally, with a delayed harvest time, the ear loss rate increased gradually. The average yield when the field was harvested on October 15th was 11.9% higher than that harvested on September 24th. The high grain broken is the main factor limiting the quality of mechanical grain harvesting of spring maize in Shanxi Province. The relationship between grain moisture content and broken rate could be fitted in the model y=0.03x2−1.224x+16.78 (R2=0.802**). The grain broken rate was the lowest when its moisture content was 20.4%. When the grain moisture content was between 15.6% and 25.2%, its broken rate was less than the national standard of 5%. Choosing the optimal variety for mechanical harvest in the spring maize area of Shanxi Province and harvesting on October 15th could guarantee harvesting quality and yield. ‘Changdan 511’ ‘Dika 159’ and ‘Changdan 716’, which have both perfect mechanical harvest quality and high yield, could be used as mechanical harvest varieties in the spring maize area of Shanxi Province.
The study of mechanical grain harvesting quality and its influential factors is significant for popularizing mechanical maize harvesting technology in Shanxi Province and enhancing the core competitiveness of the maize industry. To study the influence of harvest time on the quality and yield of maize mechanically grain harvested, five maize varieties suitable for mechanical harvest were harvested at six times (Septmber 24th, and October 1st, 8th, 15th, 22th and 29th) by the same harvester and driver. The grain moisture content, broken rate, impurity rate, as well as ear loss rate, grain loss rate, total loss rate and yield of maize were investigated. The results were as follows: first, the grain moisture content declined gradually with a delayed harvest time. With a delayed harvest time, the grain broken rate and loss rate decreased rapidly in the early period but was stable and slightly increased in the later period. Furthermore, with a delayed harvest time, the impurity rate declined gradually and tended to be stable at the end. Finally, with a delayed harvest time, the ear loss rate increased gradually. The average yield when the field was harvested on October 15th was 11.9% higher than that harvested on September 24th. The high grain broken is the main factor limiting the quality of mechanical grain harvesting of spring maize in Shanxi Province. The relationship between grain moisture content and broken rate could be fitted in the model y=0.03x2−1.224x+16.78 (R2=0.802**). The grain broken rate was the lowest when its moisture content was 20.4%. When the grain moisture content was between 15.6% and 25.2%, its broken rate was less than the national standard of 5%. Choosing the optimal variety for mechanical harvest in the spring maize area of Shanxi Province and harvesting on October 15th could guarantee harvesting quality and yield. ‘Changdan 511’ ‘Dika 159’ and ‘Changdan 716’, which have both perfect mechanical harvest quality and high yield, could be used as mechanical harvest varieties in the spring maize area of Shanxi Province.
2021, 29(10): 1712-1721.
doi: 10.13930/j.cnki.cjea.210209
Abstract:
Saline irrigation is a highly effective method of elimination of salt and drought stress in spring in the coastal severe saline-alkali soils. Tamarix chinensis, a salt-tolerant plant, plays an important role in reforming the ecological landscape of the coastal wetlands in northern China. However, the responses of plant growing rhythm of T. chinensis to long-term saline irrigation-associated fertilization remain unclear. To promote the rapid growth of T. chinensis for carbon (C) fixation, landscape construction, and saline-alkali soils reclamation, an experiment involving irrigation with local phreatic saline resources and application of nitrogen (N) and phosphorus (P) was conducted to alleviate spring drought and salt stresses, and solve the prominent problems of soil N and P deficiencies in the coastal severe saline-alkali soil. The experiment was consisted of two factors of saline irrigation and N and P fertilization over a four-year period in the coastal saline-alkali soil in the low plain of North China. Six treatments included no fertilizer as control (CK, WCK), only applying N (N, WN), applying both N and P (NP, WNP), each corresponding to no irrigation (the first) and irrigation with local phreatic saline water containing 8.02−9.34 g·L−1 salt (the second), respectively. The results showed that the growth and resprouting of T. chinensis occurred mainly in spring till to summer, but plant height and diameter increase and resprouting did not synchronized simultaneously. The trends of rates of plant height growing, resporuting and stem diameter thickening of T. chinensis during the growth season were as sloping shapes, triangle, and up fast following down slowly, respectively. In the first year of saline irrigation, soil water content, fresh weight of plant and leaf dry weight of T. chinensis was reduced significantly (P<0.01); but the stem dry weight was not impacted. However, after three-year saline water irrigation, the plant height and diameter growth was inhibited, the N content of stem and leaf were decreased significantly (P<0.05), but the P content of leaf increased by 11.8% on average, and branch numbers of T. chinensis increased significantly (P<0.05). The WNP treatment, i.e. saline irrigation and applying NP, retarded the decline of growth rate of plant height and stem diamter during spring to summer (May−June), not only accelerated the resprouting rate, but also increased the N and K contents of leaves, and promoted the transfer of Ca2+ and Mg2+ from stem to leaves, which resulted in a distribution change of ion in stem and leaf. WNP can alleviated the negative effect of continuous saline irrigation on the growth of T. chinensis by accelerating resprouting, promoting nutrient absorption and ion transport. The results provides a support for rational saline water irrigation and fertilization for T. chinensis in the costal serious saline-alkali soil.
Saline irrigation is a highly effective method of elimination of salt and drought stress in spring in the coastal severe saline-alkali soils. Tamarix chinensis, a salt-tolerant plant, plays an important role in reforming the ecological landscape of the coastal wetlands in northern China. However, the responses of plant growing rhythm of T. chinensis to long-term saline irrigation-associated fertilization remain unclear. To promote the rapid growth of T. chinensis for carbon (C) fixation, landscape construction, and saline-alkali soils reclamation, an experiment involving irrigation with local phreatic saline resources and application of nitrogen (N) and phosphorus (P) was conducted to alleviate spring drought and salt stresses, and solve the prominent problems of soil N and P deficiencies in the coastal severe saline-alkali soil. The experiment was consisted of two factors of saline irrigation and N and P fertilization over a four-year period in the coastal saline-alkali soil in the low plain of North China. Six treatments included no fertilizer as control (CK, WCK), only applying N (N, WN), applying both N and P (NP, WNP), each corresponding to no irrigation (the first) and irrigation with local phreatic saline water containing 8.02−9.34 g·L−1 salt (the second), respectively. The results showed that the growth and resprouting of T. chinensis occurred mainly in spring till to summer, but plant height and diameter increase and resprouting did not synchronized simultaneously. The trends of rates of plant height growing, resporuting and stem diameter thickening of T. chinensis during the growth season were as sloping shapes, triangle, and up fast following down slowly, respectively. In the first year of saline irrigation, soil water content, fresh weight of plant and leaf dry weight of T. chinensis was reduced significantly (P<0.01); but the stem dry weight was not impacted. However, after three-year saline water irrigation, the plant height and diameter growth was inhibited, the N content of stem and leaf were decreased significantly (P<0.05), but the P content of leaf increased by 11.8% on average, and branch numbers of T. chinensis increased significantly (P<0.05). The WNP treatment, i.e. saline irrigation and applying NP, retarded the decline of growth rate of plant height and stem diamter during spring to summer (May−June), not only accelerated the resprouting rate, but also increased the N and K contents of leaves, and promoted the transfer of Ca2+ and Mg2+ from stem to leaves, which resulted in a distribution change of ion in stem and leaf. WNP can alleviated the negative effect of continuous saline irrigation on the growth of T. chinensis by accelerating resprouting, promoting nutrient absorption and ion transport. The results provides a support for rational saline water irrigation and fertilization for T. chinensis in the costal serious saline-alkali soil.
2021, 29(10): 1722-1732.
doi: 10.13930/j.cnki.cjea.210156
Abstract:
Nano-zero-valent iron (nZVI) is widely used to remedy soil heavy metal pollution. However, the potential effects of nZVI on soil invertebrates, soil quality and microbial communities have not been well studied. In this study, we used Eisenia foetida (0, 10 pieces per kilogram soil) as the test species and examined the potential effects of nZVI (mass ratios of 0, 0.05%, 0.25%, and 0.50%) on the earthworm-bacteria-soil ecosystems after 15, 30, and 45 days of exposure. The results showed that after 45 days of exposure, there was no significant difference in survival rate and biomass of earthworms. The earthworm survival rate and content of malondialdehyde in the 0.50% nZVI system decreased by 27.66% and 0.86 nmol∙g−1, respectively, compared with those on day 15. However, the earthworm biomass increased by 1.20 times, and the catalase activity increased by 2.62 times. At the phylum or genus level, nZVI had no significant effects on the relative abundance, diversity index, and abundance index of soil microorganisms. Compared with the 0 nZVI system, the proportion of soil large aggregates (>250 μm), the average weight diameter of soil aggregates, and the content of available phosphorus (P) in the 0.50% nZVI system increased by 15.69%, 12.59%, and 21.20% under earthworm-mediated conditions, respectively. The proportion of soil macroaggregates and the average weight diameter of soil aggregates in the earthworm and nZVI composite systems were significantly higher than those in the corresponding single nZVI system, and earthworm activity significantly improved the stability of soil aggregates under nZVI stress (P<0.01). In this study, we found that long-term exposure to nZVI had no significant toxic effects on the community characteristics of soil microorganisms but promoted the growth of earthworms, which further improved the bioavailability of soil nutrients. This study provides a scientific basis for environmental safety assessments of nZVI in soil restoration applications.
Nano-zero-valent iron (nZVI) is widely used to remedy soil heavy metal pollution. However, the potential effects of nZVI on soil invertebrates, soil quality and microbial communities have not been well studied. In this study, we used Eisenia foetida (0, 10 pieces per kilogram soil) as the test species and examined the potential effects of nZVI (mass ratios of 0, 0.05%, 0.25%, and 0.50%) on the earthworm-bacteria-soil ecosystems after 15, 30, and 45 days of exposure. The results showed that after 45 days of exposure, there was no significant difference in survival rate and biomass of earthworms. The earthworm survival rate and content of malondialdehyde in the 0.50% nZVI system decreased by 27.66% and 0.86 nmol∙g−1, respectively, compared with those on day 15. However, the earthworm biomass increased by 1.20 times, and the catalase activity increased by 2.62 times. At the phylum or genus level, nZVI had no significant effects on the relative abundance, diversity index, and abundance index of soil microorganisms. Compared with the 0 nZVI system, the proportion of soil large aggregates (>250 μm), the average weight diameter of soil aggregates, and the content of available phosphorus (P) in the 0.50% nZVI system increased by 15.69%, 12.59%, and 21.20% under earthworm-mediated conditions, respectively. The proportion of soil macroaggregates and the average weight diameter of soil aggregates in the earthworm and nZVI composite systems were significantly higher than those in the corresponding single nZVI system, and earthworm activity significantly improved the stability of soil aggregates under nZVI stress (P<0.01). In this study, we found that long-term exposure to nZVI had no significant toxic effects on the community characteristics of soil microorganisms but promoted the growth of earthworms, which further improved the bioavailability of soil nutrients. This study provides a scientific basis for environmental safety assessments of nZVI in soil restoration applications.
2021, 29(10): 1733-1741.
doi: 10.13930/j.cnki.cjea.210241
Abstract:
Ecological farms are the main implementation objects for agricultural environmental policy in developed countries. Ecological farms represent the basic unit of promotion for ecological agriculture in China and have become an effective approach for agricultural green development. Based on a 7-year field investigation and 5 years of experience in the construction of eco-agriculture bases, the economic parameters of four regions of China (Northeast China, North China, the Middle and Lower Reaches of the Yangtze River, and South China) and three types of ecological farms (planting farm, breeding farm, plant-breeding combined farm) were obtained. According to the development plan of China’s new type of agricultural business and the proportion of 3%−5% ecological transformation, the development space of ecological farms at the regional and national scales was evaluated, and the industrial value of the ecological farms in promoting agricultural green development was analyzed. The latest requirements and policy recommendations for China’s recent ecological farm construction were put forward at the strategic level. The results show that: 1) the input-output efficiency of ecological farms in South China is the greatest and that in Northeast China is the lowest. With respect to ecological farm type, ecological farms carrying out planting-breeding have the greatest input-output ratio and average profit margin, but breeding-based ecological farms and planting-based ecological farms have lower input-output ratios and average profit margins. 2) There will be 30 000−50 000 ecological farms in China by 2022, and the scale of industrial value for the ecological farms ranks as North China > the Middle and Lower Reaches of the Yangtze River > Northeast China > South China, which will effectively drive market investment and provide employment opportunities. 3) Recently, it is necessary to build several ecological farms as the national demonstrations in the Yangtze River Delta region and other key areas, gradually promote the evaluation of ecological farms throughout the country. Meantime, optimizing the compensation policies, building a big data system, cultivating an industrialization platform, creating the investment and financing mechanism, and cultivating talented workforce and market subjects who would be engaged in the operation and management of ecological farms should be conducted.
Ecological farms are the main implementation objects for agricultural environmental policy in developed countries. Ecological farms represent the basic unit of promotion for ecological agriculture in China and have become an effective approach for agricultural green development. Based on a 7-year field investigation and 5 years of experience in the construction of eco-agriculture bases, the economic parameters of four regions of China (Northeast China, North China, the Middle and Lower Reaches of the Yangtze River, and South China) and three types of ecological farms (planting farm, breeding farm, plant-breeding combined farm) were obtained. According to the development plan of China’s new type of agricultural business and the proportion of 3%−5% ecological transformation, the development space of ecological farms at the regional and national scales was evaluated, and the industrial value of the ecological farms in promoting agricultural green development was analyzed. The latest requirements and policy recommendations for China’s recent ecological farm construction were put forward at the strategic level. The results show that: 1) the input-output efficiency of ecological farms in South China is the greatest and that in Northeast China is the lowest. With respect to ecological farm type, ecological farms carrying out planting-breeding have the greatest input-output ratio and average profit margin, but breeding-based ecological farms and planting-based ecological farms have lower input-output ratios and average profit margins. 2) There will be 30 000−50 000 ecological farms in China by 2022, and the scale of industrial value for the ecological farms ranks as North China > the Middle and Lower Reaches of the Yangtze River > Northeast China > South China, which will effectively drive market investment and provide employment opportunities. 3) Recently, it is necessary to build several ecological farms as the national demonstrations in the Yangtze River Delta region and other key areas, gradually promote the evaluation of ecological farms throughout the country. Meantime, optimizing the compensation policies, building a big data system, cultivating an industrialization platform, creating the investment and financing mechanism, and cultivating talented workforce and market subjects who would be engaged in the operation and management of ecological farms should be conducted.
2021, 29(10): 1742-1751.
doi: 10.13930/j.cnki.cjea.210339
Abstract:
It is necessary to determine how to appropriately expand the scale of leisure agriculture entities under constraints of existing resources and effectively promote sustainable development of urban leisure agriculture for realization of large-scale operational willingness of urban leisure agriculture entities limited to resources and policy restrictions of metropolises. Based on questionnaire data of 87 leisure agriculture entities in Shanghai, this study constructed a Logistic-ISM (interpretation structure model) model and took the willingness of leisure agriculture entities as measurement targets to study significant factors that affected the willingness, and logical hierarchical relationships between factors. Results showed that moderate expansion depended on the influence of the three levels of factors: 1) Among deep-seated factors, the leisure agriculture entities supported by government construction land were more willing to expand the scale of farmland. 2) Among middle-level indirect factors, the characteristics of agricultural resources, scientific park planning, innovative management capabilities, and business industrial structure positively affected the willingness of leisure agriculture entities to expand the scale of farmland, while the ecological nature of agricultural production was strong, the expansion of operators’ willingness to farmland size was weak. 3) Among the direct factors at the surface level, culturally functional leisure agriculture entities were willing to expand the scale of farmland, while leisure functional management entities tended to reduce the scale of farmland. To promote moderate scale operation of urban leisure agriculture, the government should introduce state-owned enterprises to play a demonstration effect to revitalize stock of rural land resources, and release value of resources. At the same time, leisure agriculture should provide strategic space for urban core functions, fully consider the heterogeneity of leisure agriculture entities, dig deep into rural cultural heritage, and promote transformation from undertaking the function of guaranteeing the supply of agricultural products for multiple functions to highlighting the economic, ecological, and esthetic values of agriculture and rural areas.
It is necessary to determine how to appropriately expand the scale of leisure agriculture entities under constraints of existing resources and effectively promote sustainable development of urban leisure agriculture for realization of large-scale operational willingness of urban leisure agriculture entities limited to resources and policy restrictions of metropolises. Based on questionnaire data of 87 leisure agriculture entities in Shanghai, this study constructed a Logistic-ISM (interpretation structure model) model and took the willingness of leisure agriculture entities as measurement targets to study significant factors that affected the willingness, and logical hierarchical relationships between factors. Results showed that moderate expansion depended on the influence of the three levels of factors: 1) Among deep-seated factors, the leisure agriculture entities supported by government construction land were more willing to expand the scale of farmland. 2) Among middle-level indirect factors, the characteristics of agricultural resources, scientific park planning, innovative management capabilities, and business industrial structure positively affected the willingness of leisure agriculture entities to expand the scale of farmland, while the ecological nature of agricultural production was strong, the expansion of operators’ willingness to farmland size was weak. 3) Among the direct factors at the surface level, culturally functional leisure agriculture entities were willing to expand the scale of farmland, while leisure functional management entities tended to reduce the scale of farmland. To promote moderate scale operation of urban leisure agriculture, the government should introduce state-owned enterprises to play a demonstration effect to revitalize stock of rural land resources, and release value of resources. At the same time, leisure agriculture should provide strategic space for urban core functions, fully consider the heterogeneity of leisure agriculture entities, dig deep into rural cultural heritage, and promote transformation from undertaking the function of guaranteeing the supply of agricultural products for multiple functions to highlighting the economic, ecological, and esthetic values of agriculture and rural areas.
2021, 29(10): 1752-1761.
doi: 10.13930/j.cnki.cjea.210281
Abstract:
In recent years, rice-crayfish co-culture has been vigorously promoted as an ecological agricultural mode. As a direct production decision-maker, farmers’ adoption intention and its influence mechanism should be clarified for the scientific promotion and sustainable development of rice-crayfish co-culture. Based on the questionnaire survey and on-the-spot interviews data of 603 farmers in five cities of Jiangsu Province, this study explored the influencing factors and their heterogeneity of farmers’ willingness to adopt the rice-crayfish co-culture mode using the theory of planned behavior and ordered logistic model. Results show that: 1) 56.88% of the farmers in the sample were willing to adopt the rice-crayfish co-culture mode, with income expectation as the key influencing factor. 2) Behavioral attitude, subjective norm, and perceived behavioral control had significant effects on farmers’ willingness to adopt the rice-crayfish co-culture mode. The order of influence was as follows: perceptual behavior control > behavior attitude > subjective norm. 3) Under different qualifications, the factors influencing farmers’ willingness to adopt the rice-crayfish co-culture mode were heterogeneous. Specifically, complete infrastructure and part-time industrialization had a stronger influence on the willingness to adopt this mode of farmers with a high expected income. The farmers who were given subsidies and less affedcted by neighborhood had a stronger willingness to adopt the rice-crayfish co-culture mode. Farmers who were less influenced by the neighborhood had higher requirements for technical training and easeness of learning. The neighborhood effect, guidance of the agricultural technology department, difficulty of technical learning, and level of education had a significant positive effect on the willingness of farmers who participated in the technical training. Distributing subsidies and improving the guidance effect from agricultural technology departments could increase farmers’ willingness to adopt this mode in areas with incomplete infrastructure. Neighborhood effect and part-time employment had a negative impact on the difficulty of technology training, while the income expectation and environmental expectation stimulated farmers to adopt the rice-crayfish co-culture mode. Based on these results, the following policy recommendations were put forward: firstly, the government should strengthen the technical training and guidance effect; second, farmland infrastructure should be improved; third, new agricultural management subjects should be fostered quickly; and finally, differentiated incentive and guidance policies should be formulated according to farmer types.
In recent years, rice-crayfish co-culture has been vigorously promoted as an ecological agricultural mode. As a direct production decision-maker, farmers’ adoption intention and its influence mechanism should be clarified for the scientific promotion and sustainable development of rice-crayfish co-culture. Based on the questionnaire survey and on-the-spot interviews data of 603 farmers in five cities of Jiangsu Province, this study explored the influencing factors and their heterogeneity of farmers’ willingness to adopt the rice-crayfish co-culture mode using the theory of planned behavior and ordered logistic model. Results show that: 1) 56.88% of the farmers in the sample were willing to adopt the rice-crayfish co-culture mode, with income expectation as the key influencing factor. 2) Behavioral attitude, subjective norm, and perceived behavioral control had significant effects on farmers’ willingness to adopt the rice-crayfish co-culture mode. The order of influence was as follows: perceptual behavior control > behavior attitude > subjective norm. 3) Under different qualifications, the factors influencing farmers’ willingness to adopt the rice-crayfish co-culture mode were heterogeneous. Specifically, complete infrastructure and part-time industrialization had a stronger influence on the willingness to adopt this mode of farmers with a high expected income. The farmers who were given subsidies and less affedcted by neighborhood had a stronger willingness to adopt the rice-crayfish co-culture mode. Farmers who were less influenced by the neighborhood had higher requirements for technical training and easeness of learning. The neighborhood effect, guidance of the agricultural technology department, difficulty of technical learning, and level of education had a significant positive effect on the willingness of farmers who participated in the technical training. Distributing subsidies and improving the guidance effect from agricultural technology departments could increase farmers’ willingness to adopt this mode in areas with incomplete infrastructure. Neighborhood effect and part-time employment had a negative impact on the difficulty of technology training, while the income expectation and environmental expectation stimulated farmers to adopt the rice-crayfish co-culture mode. Based on these results, the following policy recommendations were put forward: firstly, the government should strengthen the technical training and guidance effect; second, farmland infrastructure should be improved; third, new agricultural management subjects should be fostered quickly; and finally, differentiated incentive and guidance policies should be formulated according to farmer types.
2021, 29(10): 1762-1773.
doi: 10.13930/j.cnki.cjea.210204
Abstract:
The efficiency of agricultural carbon emissions is a bridge between crop production and emission reduction, acting as a critical indicator of the potential for emission mitigation in agricultural production. In previous estimations, the outcomes yield the input-output efficiency of agriculture under the carbon emission constraint, rather than the efficiency of agricultural carbon emission, due to failing to separate the contribution of carbon emissions from other factors. To optimize the existing idea and understand the efficiency more precisely, a theoretical framework and a corresponding equation were developed for analysis in this study. In agricultural production, given the input factors, the efficiency of agricultural carbon emissions under the prerequisite of no desirable output was defined as the ratio of the minimum possible emissions to the actual emissons. On this basis, the GB-US-SBM model was employed to calculate the slack of emissions in 30 Chinese provinces from 2000 to 2019, reflecting the distance between the actual emission and production frontier. Then, the efficiency was estimated based on the slacks and actual emissions. Finally, the influencing factors and spillover effects of agriculural carbon emissions efficiency were explored using the spatial Durbin model. Results showed that: (1) From 2000 to 2019, the average agricultural carbon emissions efficiency was 0.778 in China, indicating considerable potential for emission reduction. At the provincial level, only Inner Mongolia and Qinghai had an efficiency of 1.000, while the rest of the provinces had different spaces for emission mitigation. (2) According to the emissions quantity and efficiency, the 30 provinces were divided into four groups. The five provinces, Henan, Hebei, Shandong, Heilongjiang, and Guangxi, belonged to a group of high emissions with high efficiency. The group of low emissions with high efficiency accounted for the majority, including 12 provinces, such as Inner Mongolia and Gansu. The group with high emissions and low efficiency covered seven provinces, such as Hunan and Hubei. Six provinces, including Zhejiang and Fujian, were classified as low emissions with low efficiency. (3) The global Moran’s index was significantly greater than 0, with a P-value under 0.01, verifying that there was a positive spatial autocorrelation in the provinces. The spatial econometric regression showed that efficiency had a significant positive spatial spillover effect, suggesting that an interactive evolution existed among close provinces. Specifically, four factors—industry structure, investment intensity, financial support for agriculture, and the degree of disaster, harmed the agricultural carbon emissions efficiency directly. By contrast, the irrigation effectiveness and urbanization indicated significant positive effects. In terms of spillover effects, the intensity of a disaster in a province negatively affected the efficiency of agricultural carbon emissions in neighboring provinces, while the urbanization rate exhibited a positive effect. Hence, it was essential to pay attention to the key factors that influence efficiency. Making full use of spillover effects could also help in achieving regional agricultural low-carbon transition. Additionally, local solutions should be addressed, owing to the regional characteristics of efficiency. This study results could provide a theoretical basis for the development of low-carbon agriculture in China.
The efficiency of agricultural carbon emissions is a bridge between crop production and emission reduction, acting as a critical indicator of the potential for emission mitigation in agricultural production. In previous estimations, the outcomes yield the input-output efficiency of agriculture under the carbon emission constraint, rather than the efficiency of agricultural carbon emission, due to failing to separate the contribution of carbon emissions from other factors. To optimize the existing idea and understand the efficiency more precisely, a theoretical framework and a corresponding equation were developed for analysis in this study. In agricultural production, given the input factors, the efficiency of agricultural carbon emissions under the prerequisite of no desirable output was defined as the ratio of the minimum possible emissions to the actual emissons. On this basis, the GB-US-SBM model was employed to calculate the slack of emissions in 30 Chinese provinces from 2000 to 2019, reflecting the distance between the actual emission and production frontier. Then, the efficiency was estimated based on the slacks and actual emissions. Finally, the influencing factors and spillover effects of agriculural carbon emissions efficiency were explored using the spatial Durbin model. Results showed that: (1) From 2000 to 2019, the average agricultural carbon emissions efficiency was 0.778 in China, indicating considerable potential for emission reduction. At the provincial level, only Inner Mongolia and Qinghai had an efficiency of 1.000, while the rest of the provinces had different spaces for emission mitigation. (2) According to the emissions quantity and efficiency, the 30 provinces were divided into four groups. The five provinces, Henan, Hebei, Shandong, Heilongjiang, and Guangxi, belonged to a group of high emissions with high efficiency. The group of low emissions with high efficiency accounted for the majority, including 12 provinces, such as Inner Mongolia and Gansu. The group with high emissions and low efficiency covered seven provinces, such as Hunan and Hubei. Six provinces, including Zhejiang and Fujian, were classified as low emissions with low efficiency. (3) The global Moran’s index was significantly greater than 0, with a P-value under 0.01, verifying that there was a positive spatial autocorrelation in the provinces. The spatial econometric regression showed that efficiency had a significant positive spatial spillover effect, suggesting that an interactive evolution existed among close provinces. Specifically, four factors—industry structure, investment intensity, financial support for agriculture, and the degree of disaster, harmed the agricultural carbon emissions efficiency directly. By contrast, the irrigation effectiveness and urbanization indicated significant positive effects. In terms of spillover effects, the intensity of a disaster in a province negatively affected the efficiency of agricultural carbon emissions in neighboring provinces, while the urbanization rate exhibited a positive effect. Hence, it was essential to pay attention to the key factors that influence efficiency. Making full use of spillover effects could also help in achieving regional agricultural low-carbon transition. Additionally, local solutions should be addressed, owing to the regional characteristics of efficiency. This study results could provide a theoretical basis for the development of low-carbon agriculture in China.
2021, 29(10): 1774-1785.
doi: 10.13930/j.cnki.cjea.210225
Abstract:
Global warming is an increasingly serious problem. Carbon emissions from agriculture had hindered its transition to green agriculture, and carbon emissions from the planting industry cannot be ignored. Reducing the regional differences and clarifying dynamic evolution and convergence of the carbon compensation rates in the planting industry are conducive to the benign development of low-carbon agriculture. At present, few studies consider both agricultural carbon sources and carbon sinks, and an in-depth analysis of the carbon compensation rate of the planting industry is lacking. Existing studies on the agricultural carbon compensation rate focus only on the spatial effect of agricultural carbon but do not effectively analyze the sources and convergence of regional differences in the carbon compensation rate of the planting industry. Therefore, this study considered both the carbon sources and the carbon sinks and estimated the carbon compensation rate of the planting industry in 31 Chinese provinces (municipalities and autonomous districts) from 2002 to 2018. The Dagum Gini coefficient decomposition method was used to measure and decompose the regional differences, the dynamic evolution process of kernel density with non-parametric estimation was investigated, and the σ-convergence, absolute β-convergence, and conditional β-convergence models were used to test the convergence characteristics of the carbon compensation rate. The results were as follows: (1) The overall relative difference in the carbon compensation rate of the planting industry tended to expand. The relative differences in the eastern region expanded, while the relative differences in the central and western regions showed only little change. The relative differences between the eastern and western regions and the eastern and central regions increased, whereas that between the central and western regions decreased. The regional differences were the main reasons for the differences in the carbon compensation rates of the planting industry. (2) The carbon compensation rate of the planting industry in China increased annually, and the number of provinces with high carbon compensation rates increased. The provincial difference in carbon compensation rate first decreased and then increased. The carbon compensation rate in the eastern provinces increased gradually, and the inter-provincial absolute gap decreased, changing from polarization to unipolarization. The carbon compensation rate in the central provinces increased gradually, and the absolute gap decreased. The carbon compensation rate in the western provinces was relatively stable and showed little change. (3) There was no σ-convergence in the carbon compensation rate of the planting industry in the whole country and the eastern and western regions, but it was not obviously observed in the central region. The absolute and conditional β-convergences were significant in the whole country and the eastern, central, and western regions. The results of this study emphasize that regional heterogeneity in the carbon compensation rate of China’s planting industry is prominent and that the temporal trend of carbon compensation rate is generally increasing. The “catch-up effect” among provinces and the convergence trend of the carbon compensation rate growth among regions are apparent. In the future, it will be important to improve the carbon compensation rate of the planting industry to better formulate a green development strategy for regional agriculture and actively reduce regional emissions.
Global warming is an increasingly serious problem. Carbon emissions from agriculture had hindered its transition to green agriculture, and carbon emissions from the planting industry cannot be ignored. Reducing the regional differences and clarifying dynamic evolution and convergence of the carbon compensation rates in the planting industry are conducive to the benign development of low-carbon agriculture. At present, few studies consider both agricultural carbon sources and carbon sinks, and an in-depth analysis of the carbon compensation rate of the planting industry is lacking. Existing studies on the agricultural carbon compensation rate focus only on the spatial effect of agricultural carbon but do not effectively analyze the sources and convergence of regional differences in the carbon compensation rate of the planting industry. Therefore, this study considered both the carbon sources and the carbon sinks and estimated the carbon compensation rate of the planting industry in 31 Chinese provinces (municipalities and autonomous districts) from 2002 to 2018. The Dagum Gini coefficient decomposition method was used to measure and decompose the regional differences, the dynamic evolution process of kernel density with non-parametric estimation was investigated, and the σ-convergence, absolute β-convergence, and conditional β-convergence models were used to test the convergence characteristics of the carbon compensation rate. The results were as follows: (1) The overall relative difference in the carbon compensation rate of the planting industry tended to expand. The relative differences in the eastern region expanded, while the relative differences in the central and western regions showed only little change. The relative differences between the eastern and western regions and the eastern and central regions increased, whereas that between the central and western regions decreased. The regional differences were the main reasons for the differences in the carbon compensation rates of the planting industry. (2) The carbon compensation rate of the planting industry in China increased annually, and the number of provinces with high carbon compensation rates increased. The provincial difference in carbon compensation rate first decreased and then increased. The carbon compensation rate in the eastern provinces increased gradually, and the inter-provincial absolute gap decreased, changing from polarization to unipolarization. The carbon compensation rate in the central provinces increased gradually, and the absolute gap decreased. The carbon compensation rate in the western provinces was relatively stable and showed little change. (3) There was no σ-convergence in the carbon compensation rate of the planting industry in the whole country and the eastern and western regions, but it was not obviously observed in the central region. The absolute and conditional β-convergences were significant in the whole country and the eastern, central, and western regions. The results of this study emphasize that regional heterogeneity in the carbon compensation rate of China’s planting industry is prominent and that the temporal trend of carbon compensation rate is generally increasing. The “catch-up effect” among provinces and the convergence trend of the carbon compensation rate growth among regions are apparent. In the future, it will be important to improve the carbon compensation rate of the planting industry to better formulate a green development strategy for regional agriculture and actively reduce regional emissions.
2021, 29(10): 1786-1799.
doi: 10.13930/j.cnki.cjea.210106
Abstract:
Green development is important for China’s future food safety, and measuring green productivity is an effective method to explore ways to increase green grains production. Based on the differences in the endowment of cultivated land resources in different regions, this study adopted the ecological services value evaluation method to measure the ecological value of cultivated land during the process of grain production. To incorporate the nutrient pollution and non-nutrient pollution generated in the process of grain production, the global Malmquise Luenberger index and the super efficiency model were used from the static and dynamic perspectives, to calculate China’s total factor productivity and input-output redundancy rate from 1997 to 2019. To better understand the temporal and spatial changes in China’s green total factor productivity, the spatial development characteristics of the agricultural production factors were investigated in the selected six years (1997, 2001, 2005, 2009, 2013 and 2019) using the equidistant distribution method, and Moran’s I index was used to study the spatial heterogeneity and agglomeration of green total factor productivity of grains in China. The results showed that: 1) During the study period, the ecological value of grain production reduced by 0.39%, from 647.157 billion Yuan in 1997 to 644.616 billion Yuan in 2019; a loss of 2.541 billion Yuan. The ecological value in the northeast, central, and southwest regions increased, whereas that in the east and northwest regions decreased. 2) Analysis of the environmental impact of grain production showed that the traditional total factor productivity, which does not consider environmental effects, tended to ignore the positive and negative aspects of grain production and cannot accurately assess the true efficiency of China’s grain production. After accounting for environmental factors, such as the ecological value of grain production and agricultural non-point source pollution, this study found that the green total factor productivity of grains increased by 0.60% annually, from 0.9754 in 1997 to 1.0990 in 2019, driven mainly by technological progress (1.0308). The driving effect of technical efficiency (0.9973) was weak. 3) The proportion of provinces (cities) that were relatively effective in the green total factor productivity of grains increased from 9.68% in 1997 to 67.74% in 2019. In terms of time and space, the relatively effective provinces (cities) was mainly in the eastern region and then graduallydeveloped to the northeast, central, and northwest regions. 4) Due to high pollution emissions and resource consumption, the main reasons for the provinces (cities) that were relatively ineffective in green total factor productivity of grains were the redundancy of employees in the primary industry, the use of agricultural film, and carbon emissions. 5) The green total factor productivity of grains in China had a significant positive spatial correlation dominated by high-high agglomeration, and the green total factor productivity of grains showed spatial characteristics of agglomeration in the central and southwestern high-efficiency areas. The degree of agglomeration was increasing. Based on the above results, this study advocates for a better understanding of the positive and negative effects of grain production activities, strict control of the non-grain and non-agricultural phenomenon of agricultural land, and the promotion of advanced agricultural technologies to promote the green total factor productivity of grains.
Green development is important for China’s future food safety, and measuring green productivity is an effective method to explore ways to increase green grains production. Based on the differences in the endowment of cultivated land resources in different regions, this study adopted the ecological services value evaluation method to measure the ecological value of cultivated land during the process of grain production. To incorporate the nutrient pollution and non-nutrient pollution generated in the process of grain production, the global Malmquise Luenberger index and the super efficiency model were used from the static and dynamic perspectives, to calculate China’s total factor productivity and input-output redundancy rate from 1997 to 2019. To better understand the temporal and spatial changes in China’s green total factor productivity, the spatial development characteristics of the agricultural production factors were investigated in the selected six years (1997, 2001, 2005, 2009, 2013 and 2019) using the equidistant distribution method, and Moran’s I index was used to study the spatial heterogeneity and agglomeration of green total factor productivity of grains in China. The results showed that: 1) During the study period, the ecological value of grain production reduced by 0.39%, from 647.157 billion Yuan in 1997 to 644.616 billion Yuan in 2019; a loss of 2.541 billion Yuan. The ecological value in the northeast, central, and southwest regions increased, whereas that in the east and northwest regions decreased. 2) Analysis of the environmental impact of grain production showed that the traditional total factor productivity, which does not consider environmental effects, tended to ignore the positive and negative aspects of grain production and cannot accurately assess the true efficiency of China’s grain production. After accounting for environmental factors, such as the ecological value of grain production and agricultural non-point source pollution, this study found that the green total factor productivity of grains increased by 0.60% annually, from 0.9754 in 1997 to 1.0990 in 2019, driven mainly by technological progress (1.0308). The driving effect of technical efficiency (0.9973) was weak. 3) The proportion of provinces (cities) that were relatively effective in the green total factor productivity of grains increased from 9.68% in 1997 to 67.74% in 2019. In terms of time and space, the relatively effective provinces (cities) was mainly in the eastern region and then graduallydeveloped to the northeast, central, and northwest regions. 4) Due to high pollution emissions and resource consumption, the main reasons for the provinces (cities) that were relatively ineffective in green total factor productivity of grains were the redundancy of employees in the primary industry, the use of agricultural film, and carbon emissions. 5) The green total factor productivity of grains in China had a significant positive spatial correlation dominated by high-high agglomeration, and the green total factor productivity of grains showed spatial characteristics of agglomeration in the central and southwestern high-efficiency areas. The degree of agglomeration was increasing. Based on the above results, this study advocates for a better understanding of the positive and negative effects of grain production activities, strict control of the non-grain and non-agricultural phenomenon of agricultural land, and the promotion of advanced agricultural technologies to promote the green total factor productivity of grains.
2021, 29(10): 1800-1814.
doi: 10.13930/j.cnki.cjea.210160
Abstract:
A comprehensive assessment framework for watershed ecosystem services and trade-offs was proposed for watershed governance and regional sustainable development in this paper. The framework integrated both shared socioeconomic pathways (SSPs) and future land use simulation (FLUS) models. The socioeconomic data of China’s provincial SSPs considering domestic development and regional differences were introduced to the FLUS model, meeting the needs of regional level land-use simulation scenarios and fully considering the interaction between human socio-economic activities and the natural environment. Taking the Hanjiang River Basin as an example, the FLUS models under different SSPs scenarios were built to evaluate the ecological and environmental effects on land-use change. We further investigated the response of water conservation and water quality purification services to social development decision-making and spatiotemporal evolution by using InVEST model. Results showed that: 1) the water production depth in 2035 under all the SSP scenarios was significantly higher than that in 2015. The increment under the SSP1 and SSP2 scenarios was relatively small, and the increment under the SSP3 scenario was relatively higher with the most intense change. The areas with increased water production depth were mainly concentrated in the southeast, central, and western regions of the Hanjiang River Basin. 2) From 2015 to 2035, due to frequent human activities and rapid urban expansion, in areas where the water production depth increased, urbanized land also increased significantly. According to the land-use simulation and water production depth change results, urbanized land had a strong water production capacity due to low vegetation coverage, weak evapotranspiration, and low permeability of hardened ground. 3) The nitrogen and phosphorus loads in the SSPs scenarios in 2035 were lower than those in 2015. The reduction under the SSP1 and SSP5 scenarios was relatively large, and the SSP3 scenario was the same as that in 2015, but the change was the most intense. The areas with increased nitrogen and phosphorus loads were mainly concentrated in the southeast and western regions. 4) According to the results of land-use simulation and nitrogen and phosphorus load change, the urbanized land had more pollutants due to the frequent human socio-economic activities, while the cropland was due to the use of chemical fertilizers and pesticides in the process of agricultural production, making part of the nitrogen and phosphorus elements not absorbed by crops. The two types of land-use caused serious pollution in the water environment of the basin. The future development planning of the Hanjiang River Basin can be based on the SSP1 scenario, referring to the economic and technological development model under the SSP5 scenario, combined with the basin functional district, optimizing the land-use structure, and ensuring the water ecological environment security of the basin while paying attention to economic development. The results of this study can be used to prepare territorial spatial planning and sustainable water resource asset management in the Hanjiang River Basin, support the construction of the Hanjiang River eco-economic belt, and promote the improvement of the water ecological environment in the Yangtze River Basin.
A comprehensive assessment framework for watershed ecosystem services and trade-offs was proposed for watershed governance and regional sustainable development in this paper. The framework integrated both shared socioeconomic pathways (SSPs) and future land use simulation (FLUS) models. The socioeconomic data of China’s provincial SSPs considering domestic development and regional differences were introduced to the FLUS model, meeting the needs of regional level land-use simulation scenarios and fully considering the interaction between human socio-economic activities and the natural environment. Taking the Hanjiang River Basin as an example, the FLUS models under different SSPs scenarios were built to evaluate the ecological and environmental effects on land-use change. We further investigated the response of water conservation and water quality purification services to social development decision-making and spatiotemporal evolution by using InVEST model. Results showed that: 1) the water production depth in 2035 under all the SSP scenarios was significantly higher than that in 2015. The increment under the SSP1 and SSP2 scenarios was relatively small, and the increment under the SSP3 scenario was relatively higher with the most intense change. The areas with increased water production depth were mainly concentrated in the southeast, central, and western regions of the Hanjiang River Basin. 2) From 2015 to 2035, due to frequent human activities and rapid urban expansion, in areas where the water production depth increased, urbanized land also increased significantly. According to the land-use simulation and water production depth change results, urbanized land had a strong water production capacity due to low vegetation coverage, weak evapotranspiration, and low permeability of hardened ground. 3) The nitrogen and phosphorus loads in the SSPs scenarios in 2035 were lower than those in 2015. The reduction under the SSP1 and SSP5 scenarios was relatively large, and the SSP3 scenario was the same as that in 2015, but the change was the most intense. The areas with increased nitrogen and phosphorus loads were mainly concentrated in the southeast and western regions. 4) According to the results of land-use simulation and nitrogen and phosphorus load change, the urbanized land had more pollutants due to the frequent human socio-economic activities, while the cropland was due to the use of chemical fertilizers and pesticides in the process of agricultural production, making part of the nitrogen and phosphorus elements not absorbed by crops. The two types of land-use caused serious pollution in the water environment of the basin. The future development planning of the Hanjiang River Basin can be based on the SSP1 scenario, referring to the economic and technological development model under the SSP5 scenario, combined with the basin functional district, optimizing the land-use structure, and ensuring the water ecological environment security of the basin while paying attention to economic development. The results of this study can be used to prepare territorial spatial planning and sustainable water resource asset management in the Hanjiang River Basin, support the construction of the Hanjiang River eco-economic belt, and promote the improvement of the water ecological environment in the Yangtze River Basin.
2016, 24(4): 403-415.
摘要：
间套作是我国传统农业的精髓, 其存在2 000多年, 必然蕴含重要的科学原理。过去的研究表明其不仅能够大幅度提高作物产量, 而且能够充分利用地上部的光热资源, 充分挖掘和利用地下部水分养分资源, 强化农田生态系统服务功能。近年来, 国内外对其资源高效利用的研究取得了显著的进步, 特别是地下部资源高效利用方面。本文首先综述了相关研究的进展: 间套作作为增加农田生态系统生物多样性的重要措施, 具有重要的生态功能, 如提高作物产量, 增加作物生产力的稳定性, 充分利用地上部光热资源和土壤水分、土壤和肥料中的氮素和磷素以及微量元素等。随后, 对间套作提高资源利用效率的机制进行了分析, 包括水分需求上的时间和空间生态位互补, 豆科/禾本科间作体系中的豆科作物生物固氮和禾本科作物对土壤氮素利用上的互补和促进作用; 磷活化能力强弱搭配的间作体系中, 磷活化能力强的作物对活化能力弱的作物的促进作用; 双子叶和单子叶植物的搭配, 改善双子叶植物的Fe、Zn等微量元素的含量等。最后, 对间套作进一步研究方向和应用提出了一些看法和思路。在研究方面, 包括作物多样性与农业可持续发展, 地下部作物种间信号的传递, 地上地下部多样性的互反馈调节机制, 以及作物生长模型等。在应用方面, 包括豆科作物纳入农业生产体系发展生态集约化农业, 利用间套作发展有机农业, 利用种间相互作用提高磷肥利用率和增加作物可食部分的微量元素含量等。并认为间套作中的机械化、育种等问题的解决将有利于间套作的进一步发展。
间套作是我国传统农业的精髓, 其存在2 000多年, 必然蕴含重要的科学原理。过去的研究表明其不仅能够大幅度提高作物产量, 而且能够充分利用地上部的光热资源, 充分挖掘和利用地下部水分养分资源, 强化农田生态系统服务功能。近年来, 国内外对其资源高效利用的研究取得了显著的进步, 特别是地下部资源高效利用方面。本文首先综述了相关研究的进展: 间套作作为增加农田生态系统生物多样性的重要措施, 具有重要的生态功能, 如提高作物产量, 增加作物生产力的稳定性, 充分利用地上部光热资源和土壤水分、土壤和肥料中的氮素和磷素以及微量元素等。随后, 对间套作提高资源利用效率的机制进行了分析, 包括水分需求上的时间和空间生态位互补, 豆科/禾本科间作体系中的豆科作物生物固氮和禾本科作物对土壤氮素利用上的互补和促进作用; 磷活化能力强弱搭配的间作体系中, 磷活化能力强的作物对活化能力弱的作物的促进作用; 双子叶和单子叶植物的搭配, 改善双子叶植物的Fe、Zn等微量元素的含量等。最后, 对间套作进一步研究方向和应用提出了一些看法和思路。在研究方面, 包括作物多样性与农业可持续发展, 地下部作物种间信号的传递, 地上地下部多样性的互反馈调节机制, 以及作物生长模型等。在应用方面, 包括豆科作物纳入农业生产体系发展生态集约化农业, 利用间套作发展有机农业, 利用种间相互作用提高磷肥利用率和增加作物可食部分的微量元素含量等。并认为间套作中的机械化、育种等问题的解决将有利于间套作的进一步发展。
2017, 25(1): 1-7.
doi: 10.13930/j.cnki.cjea.160838
摘要：
人类农业经历过刀耕火种、传统小型农业和工业化农业等形态之后，正在进入一个农业的生态化阶段。各国实施农业生态转型的转折点通常在人均GDP达1万~3万美元左右。不同国家、地区和国际社会根据不同社会背景，分别采用了不同的转型策略、转型路径和转型名称。我国社会经济发展水平已经接近和到达实施农业生态转型的拐点。中国2015年起连续出台了一系列重大的政策措施，从发展目标、指导思想、发展方式、实施手段和管理制度等方面全面推进农业的生态转型，生态农业得到了社会的广泛认可和关注。明确生态农业概念与其他相关概念的关系有利于形成农业生态转型的合力。文章在分析我国农业生态转型的优势与挑战之后，提出了我国未来农业生态转型的方略。
人类农业经历过刀耕火种、传统小型农业和工业化农业等形态之后，正在进入一个农业的生态化阶段。各国实施农业生态转型的转折点通常在人均GDP达1万~3万美元左右。不同国家、地区和国际社会根据不同社会背景，分别采用了不同的转型策略、转型路径和转型名称。我国社会经济发展水平已经接近和到达实施农业生态转型的拐点。中国2015年起连续出台了一系列重大的政策措施，从发展目标、指导思想、发展方式、实施手段和管理制度等方面全面推进农业的生态转型，生态农业得到了社会的广泛认可和关注。明确生态农业概念与其他相关概念的关系有利于形成农业生态转型的合力。文章在分析我国农业生态转型的优势与挑战之后，提出了我国未来农业生态转型的方略。
2017, 25(9): 1245-1253.
doi: 10.13930/j.cnki.cjea.170739
摘要：
近年来，稻虾[水稻-克氏原螯虾（小龙虾）]共作模式由于其较高的综合效益而在全国范围内得以大力发展。其中以湖北省稻虾共作发展最为迅速，面积大，技术也较为成熟，并形成了"潜江模式"。本文介绍了稻虾共作模式的特点及其发展情况，以湖北省稻虾共作模式为研究对象，采用产业调查，结合试验示范和定位试验，研究了稻虾共作模式的生产和生态效应，重点分析了稻虾共作模式的"双刃性"。稻虾共作模式的"双刃性"主要体现在（1）稳粮增效，但同时存在重虾轻稻的现象：稻虾共作模式较传统水稻单作模式可增产4.63%~14.01%，改善稻米品质，但部分稻虾共作模式中忽略水稻的管理，导致水稻产量偏低；（2）提高土壤肥力，但同时加剧了土壤次生潜育化：稻虾共作模式土壤中易氧化态有机碳（ROC）、全氮、全磷、全钾含量要高于传统水稻单作模式，但稻虾共作模式土壤颜色偏暗，土壤结构更为紧密，潜育化明显；（3）涵养水源，但同时可能增加水资源消耗：稻虾共作模式中地下水位高的稻田水分利用率提高，储水功能增强，但地下水位低的稻田可能增加50%~80%的耗水量；（4）减肥减药、提高水体养分含量，但同时增加了水体富营养化的风险：稻虾共作模式肥料和农药成本分别降低了79.5%和50.0%，稻虾共作模式田面水的全氮、全磷含量及硝态氮、氨态氮含量均高于水稻单作；（5）虫害减轻，但某些病害加重，同时生物多样性发生变化：稻虾共作模式螟虫发生减轻，但基腐病加重，生物多样性随共作年限先降低后又增高。根据以上现状与问题，本研究提出了稻虾共作的模式优化及建议，如因地制宜，避免盲目发展；研究标准，规范化发展；优化模式，科学水肥调控；因势利导，防治病虫草害，为稻虾共作模式的可持续发展提供依据。
近年来，稻虾[水稻-克氏原螯虾（小龙虾）]共作模式由于其较高的综合效益而在全国范围内得以大力发展。其中以湖北省稻虾共作发展最为迅速，面积大，技术也较为成熟，并形成了"潜江模式"。本文介绍了稻虾共作模式的特点及其发展情况，以湖北省稻虾共作模式为研究对象，采用产业调查，结合试验示范和定位试验，研究了稻虾共作模式的生产和生态效应，重点分析了稻虾共作模式的"双刃性"。稻虾共作模式的"双刃性"主要体现在（1）稳粮增效，但同时存在重虾轻稻的现象：稻虾共作模式较传统水稻单作模式可增产4.63%~14.01%，改善稻米品质，但部分稻虾共作模式中忽略水稻的管理，导致水稻产量偏低；（2）提高土壤肥力，但同时加剧了土壤次生潜育化：稻虾共作模式土壤中易氧化态有机碳（ROC）、全氮、全磷、全钾含量要高于传统水稻单作模式，但稻虾共作模式土壤颜色偏暗，土壤结构更为紧密，潜育化明显；（3）涵养水源，但同时可能增加水资源消耗：稻虾共作模式中地下水位高的稻田水分利用率提高，储水功能增强，但地下水位低的稻田可能增加50%~80%的耗水量；（4）减肥减药、提高水体养分含量，但同时增加了水体富营养化的风险：稻虾共作模式肥料和农药成本分别降低了79.5%和50.0%，稻虾共作模式田面水的全氮、全磷含量及硝态氮、氨态氮含量均高于水稻单作；（5）虫害减轻，但某些病害加重，同时生物多样性发生变化：稻虾共作模式螟虫发生减轻，但基腐病加重，生物多样性随共作年限先降低后又增高。根据以上现状与问题，本研究提出了稻虾共作的模式优化及建议，如因地制宜，避免盲目发展；研究标准，规范化发展；优化模式，科学水肥调控；因势利导，防治病虫草害，为稻虾共作模式的可持续发展提供依据。
2017, 25(1): 36-46.
doi: 10.13930/j.cnki.cjea.160632
摘要：
化感现象作为植物之间的一种相互作用方式，在农林业生产中广泛存在。合理利用植物之间的化感作用，对于生产实践具有重要的指导意义。研究表明，化感物质可促进或抑制不同物种种子的萌发过程，这对于植物的生长发育、植物群落的组成与分布以及生态系统的平衡有着重要影响。本文从化感物质对种子萌发的影响与其生态学意义两个方面进行了综述。一方面，在阐述化感作用影响种子萌发的基础上，进一步总结了化感物质抑制植物种子萌发的生理生化机制。包括：化感物质通过抑制胚根和胚轴的伸长，破坏亚细胞结构，干扰植物激素及活性氧的合成与代谢，造成细胞损伤，从而阻碍种子萌发；抑制种子中储存物质的代谢，阻碍种子萌发过程中的物质以及能量转换，导致种子萌发受阻等。另一方面，本文从化感作用在抑制农田杂草及影响生态系统稳定性两个方面，阐述了化感物质调控种子萌发的生态学意义。讨论了农作物的化感抑草作用，农林业生产中的化感自毒作用以及化感作用造成的生物入侵等，以期为农林业生产提供借鉴。最后，根据目前研究进展，对本领域未来研究方向进行了展望和讨论。
化感现象作为植物之间的一种相互作用方式，在农林业生产中广泛存在。合理利用植物之间的化感作用，对于生产实践具有重要的指导意义。研究表明，化感物质可促进或抑制不同物种种子的萌发过程，这对于植物的生长发育、植物群落的组成与分布以及生态系统的平衡有着重要影响。本文从化感物质对种子萌发的影响与其生态学意义两个方面进行了综述。一方面，在阐述化感作用影响种子萌发的基础上，进一步总结了化感物质抑制植物种子萌发的生理生化机制。包括：化感物质通过抑制胚根和胚轴的伸长，破坏亚细胞结构，干扰植物激素及活性氧的合成与代谢，造成细胞损伤，从而阻碍种子萌发；抑制种子中储存物质的代谢，阻碍种子萌发过程中的物质以及能量转换，导致种子萌发受阻等。另一方面，本文从化感作用在抑制农田杂草及影响生态系统稳定性两个方面，阐述了化感物质调控种子萌发的生态学意义。讨论了农作物的化感抑草作用，农林业生产中的化感自毒作用以及化感作用造成的生物入侵等，以期为农林业生产提供借鉴。最后，根据目前研究进展，对本领域未来研究方向进行了展望和讨论。
2016, 24(12): 1633-1642.
doi: 10.13930/j.cnki.cjea.160357
摘要：
秸秆的质量, 特别是C/N是影响秸秆分解速率和养分释放的重要因素。在秸秆还田条件下, 如何科学合理地施用氮肥是秸秆利用和优化施肥研究的关键问题。本研究以秸秆还田施入碳氮的C/N为切入点, 于2012—2013年通过田间试验(设秸秆不还田不施肥、秸秆还田不施氮、秸秆还田施用无机氮肥调节C/N为10∶1、16∶1和25∶1以及秸秆还田施用有机氮肥调节C/N为25∶1处理), 研究秸秆还田不同氮输入对小麦玉米轮作田土壤无机氮、土壤微生物量氮、酶活性以及作物产量的影响。结果表明: 1)在C/N为25∶1下, 施用有机氮肥和无机氮肥对土壤无机氮含量无显著影响; 在施用无机氮肥的情况下, C/N越低土壤无机氮含量越高。2)秸秆还田施氮提高了土壤微生物量氮含量, 但是各秸秆还田施氮处理之间差异不显著; 秸秆还田不同施氮处理对脲酶活性无显著影响; 秸秆还田施氮提高了FDA水解酶活性, 并随C/N降低呈升高趋势, 施用无机氮肥的效果强于施用有机氮肥的。3)秸秆还田施用无机氮肥显著提高了小麦和玉米地上部生物量, 施用无机氮肥调节C/N为10∶1和16∶1相比于C/N为25∶1提高了小麦和玉米的苗期和成熟期地上部生物量; 施用有机氮肥调节C/N为25∶1相比秸秆还田不施氮对地上部生物量无显著影响。秸秆还田施用无机氮肥提高了作物产量, 施用无机氮肥调节C/N为16∶1产量最高, 而施用有机氮肥调节C/N为25∶1有降低作物产量的趋势。综合以上结果来看, 施用无机氮肥调节C/N为16∶1较为合理。
秸秆的质量, 特别是C/N是影响秸秆分解速率和养分释放的重要因素。在秸秆还田条件下, 如何科学合理地施用氮肥是秸秆利用和优化施肥研究的关键问题。本研究以秸秆还田施入碳氮的C/N为切入点, 于2012—2013年通过田间试验(设秸秆不还田不施肥、秸秆还田不施氮、秸秆还田施用无机氮肥调节C/N为10∶1、16∶1和25∶1以及秸秆还田施用有机氮肥调节C/N为25∶1处理), 研究秸秆还田不同氮输入对小麦玉米轮作田土壤无机氮、土壤微生物量氮、酶活性以及作物产量的影响。结果表明: 1)在C/N为25∶1下, 施用有机氮肥和无机氮肥对土壤无机氮含量无显著影响; 在施用无机氮肥的情况下, C/N越低土壤无机氮含量越高。2)秸秆还田施氮提高了土壤微生物量氮含量, 但是各秸秆还田施氮处理之间差异不显著; 秸秆还田不同施氮处理对脲酶活性无显著影响; 秸秆还田施氮提高了FDA水解酶活性, 并随C/N降低呈升高趋势, 施用无机氮肥的效果强于施用有机氮肥的。3)秸秆还田施用无机氮肥显著提高了小麦和玉米地上部生物量, 施用无机氮肥调节C/N为10∶1和16∶1相比于C/N为25∶1提高了小麦和玉米的苗期和成熟期地上部生物量; 施用有机氮肥调节C/N为25∶1相比秸秆还田不施氮对地上部生物量无显著影响。秸秆还田施用无机氮肥提高了作物产量, 施用无机氮肥调节C/N为16∶1产量最高, 而施用有机氮肥调节C/N为25∶1有降低作物产量的趋势。综合以上结果来看, 施用无机氮肥调节C/N为16∶1较为合理。
2017, 25(2): 188-199.
doi: 10.13930/j.cnki.cjea.160748
摘要：
以水稻、小麦、玉米秸秆和油菜、蚕豆青秆为研究对象，采用尼龙网袋法，研究了不同秸秆翻埋入旱地和水田后的腐解特性及养分释放规律，以期为紫色丘陵区农业秸秆循环利用和秸秆还田技术提供理论依据。结果表明：秸秆翻埋还田后，5种供试秸秆腐解速率均表现为前期（0~60 d）快、后期（60~360 d）慢。经过360 d的腐解，旱地秸秆累积腐解率为52.88%~75.80%，表现为油菜 > 水稻 > 玉米 > 小麦 > 蚕豆趋势，且蚕豆青秆累积腐解率显著低于其余秸秆；水田中秸秆累积腐解率为45.01%~62.12%，表现为水稻 > 玉米 > 小麦 > 油菜 > 蚕豆趋势。5种秸秆在旱地和水田中养分释放率均表现为钾 > 磷 > 氮 > 碳，在试验终点，旱地中秸秆碳、氮、磷和钾释放率分别为65.50%~87.37%、54.64%~69.72%、89.65%~98.96%和79.92%~96.63%，且油菜秸秆养分释放率高于其他4种秸秆；水田中秸秆碳、氮、磷、钾释放率变幅分别为49.95%~69.57%、32.89%~77.11%、90.70%~96.80%、77.45%~90.47%。总体表现为秸秆在旱地土壤中的累积腐解率和养分释放率均大于水田，旱地油菜和水稻秸秆较易腐解，水田水稻和玉米秸秆较易腐解释；秸秆中钾素释放速率较高。
以水稻、小麦、玉米秸秆和油菜、蚕豆青秆为研究对象，采用尼龙网袋法，研究了不同秸秆翻埋入旱地和水田后的腐解特性及养分释放规律，以期为紫色丘陵区农业秸秆循环利用和秸秆还田技术提供理论依据。结果表明：秸秆翻埋还田后，5种供试秸秆腐解速率均表现为前期（0~60 d）快、后期（60~360 d）慢。经过360 d的腐解，旱地秸秆累积腐解率为52.88%~75.80%，表现为油菜 > 水稻 > 玉米 > 小麦 > 蚕豆趋势，且蚕豆青秆累积腐解率显著低于其余秸秆；水田中秸秆累积腐解率为45.01%~62.12%，表现为水稻 > 玉米 > 小麦 > 油菜 > 蚕豆趋势。5种秸秆在旱地和水田中养分释放率均表现为钾 > 磷 > 氮 > 碳，在试验终点，旱地中秸秆碳、氮、磷和钾释放率分别为65.50%~87.37%、54.64%~69.72%、89.65%~98.96%和79.92%~96.63%，且油菜秸秆养分释放率高于其他4种秸秆；水田中秸秆碳、氮、磷、钾释放率变幅分别为49.95%~69.57%、32.89%~77.11%、90.70%~96.80%、77.45%~90.47%。总体表现为秸秆在旱地土壤中的累积腐解率和养分释放率均大于水田，旱地油菜和水稻秸秆较易腐解，水田水稻和玉米秸秆较易腐解释；秸秆中钾素释放速率较高。
2017, 25(1): 61-68.
doi: 10.13930/j.cnki.cjea.160661
摘要：
稻虾共作模式是一种以涝渍水田为基础，以种稻为中心，稻草还田养虾为特点的复合生态系统。本文通过10年（2005-2015年）定位试验，以中稻单作模式为对照，研究了稻虾共作模式对0~10 cm、10~20 cm、20~30 cm和30~40 cm土层土壤理化性状以及水稻产量的影响；采用投入产出法，评估了稻虾共作模式的经济效益。结果表明，长期稻虾共作模式显著降低了15~30 cm土层的土壤紧实度，其在15 cm、20 cm、25 cm和30 cm处的土壤紧实度较中稻单作模式分别降低了20.9%、29.9%、24.8%和14.7%。长期稻虾共作模式提高了0~40 cm土层中>0.25 mm水稳性团聚体数量、平均质量直径和几何平均直径，但降低了0~20 cm土层的团聚体分形维数。相对于中稻单作模式，长期稻虾共作模式显著提高了0~40 cm土层有机碳、全钾和碱解氮含量，0~30 cm土层全氮含量，0~10 cm土层全磷和速效磷含量以及20~40 cm土层速效钾含量。稻虾共作模式显著降低了0~10 cm土层还原性物质总量，但提高了20~30 cm土层土壤还原性物质总量。稻虾共作模式的水稻产量较中稻单作模式显著提高，增幅为9.5%，其总产值、利润和产投比较中稻单作模式分别增加了46 818.0元·hm-2、40 188.0元·hm-2和100.0%。可见稻虾共作模式改善了土壤结构，增加了土壤养分，提高了水稻产量以及经济效益，但增加了10 cm以下土层潜育化的风险。
稻虾共作模式是一种以涝渍水田为基础，以种稻为中心，稻草还田养虾为特点的复合生态系统。本文通过10年（2005-2015年）定位试验，以中稻单作模式为对照，研究了稻虾共作模式对0~10 cm、10~20 cm、20~30 cm和30~40 cm土层土壤理化性状以及水稻产量的影响；采用投入产出法，评估了稻虾共作模式的经济效益。结果表明，长期稻虾共作模式显著降低了15~30 cm土层的土壤紧实度，其在15 cm、20 cm、25 cm和30 cm处的土壤紧实度较中稻单作模式分别降低了20.9%、29.9%、24.8%和14.7%。长期稻虾共作模式提高了0~40 cm土层中>0.25 mm水稳性团聚体数量、平均质量直径和几何平均直径，但降低了0~20 cm土层的团聚体分形维数。相对于中稻单作模式，长期稻虾共作模式显著提高了0~40 cm土层有机碳、全钾和碱解氮含量，0~30 cm土层全氮含量，0~10 cm土层全磷和速效磷含量以及20~40 cm土层速效钾含量。稻虾共作模式显著降低了0~10 cm土层还原性物质总量，但提高了20~30 cm土层土壤还原性物质总量。稻虾共作模式的水稻产量较中稻单作模式显著提高，增幅为9.5%，其总产值、利润和产投比较中稻单作模式分别增加了46 818.0元·hm-2、40 188.0元·hm-2和100.0%。可见稻虾共作模式改善了土壤结构，增加了土壤养分，提高了水稻产量以及经济效益，但增加了10 cm以下土层潜育化的风险。
2016, 24(9): 1254-1264.
doi: 10.13930/j.cnki.cjea.151237
摘要：
叶面积指数(LAI)是评价作物长势的重要农学参数之一, 利用遥感技术准确估测作物叶面积指数(LAI)对精准农业意义重大。目前, 数码相机与无人机系统组成的高性价比遥感监测系统在农业研究中已取得一些成果, 但利用无人机数码影像开展作物LAI估测研究还少有尝试。为论证利用无人机数码影像估测冬小麦LAI的可行性, 本文以获取到的3个关键生育期(孕穗期、开花期和灌浆期)冬小麦无人机数码影像为数据源, 利用数字图像转换原理构建出10种数字图像特征参数, 并系统地分析了3个生育期内两个冬小麦品种在4种氮水平下的LAI与数字图像特征参数之间的关联性。结果表明, 在LAI随生育期发生变化的同时, 10种数字图像特征参数中R/(R+G+B)和本文提出的基于无人机数码影像红、绿、蓝通道DN值以及可见光大气阻抗植被指数(VARI)计算原理构建的数字图像特征参数UAV-based VARIRGB也有规律性变化, 说明冬小麦的施氮差异不仅对LAI有影响, 也对某些数字图像特征参数有一定影响; 在不同条件(品种、氮营养水平以及生育期)下的数字图像特征参数与LAI的相关性分析中, R/(R+G+B)和UAV-based VARIRGB与LAI显著相关。进而, 研究评价了R/(R+G+B)和UAV-based VARIRGB构建的LAI估测模型, 最终确定UAV-based VARIRGB为估测冬小麦LAI的最佳参数指标。结果表明UAV-based VARIRGB指数模型估测的LAI与实测LAI拟合性较好(R2=0.71, RMSE=0.8, P<0.01)。本研究证明将无人机数码影像应用于冬小麦LAI探测是可行的, 这也为高性价比无人机遥感系统的精准农业应用增添了新成果和经验。
叶面积指数(LAI)是评价作物长势的重要农学参数之一, 利用遥感技术准确估测作物叶面积指数(LAI)对精准农业意义重大。目前, 数码相机与无人机系统组成的高性价比遥感监测系统在农业研究中已取得一些成果, 但利用无人机数码影像开展作物LAI估测研究还少有尝试。为论证利用无人机数码影像估测冬小麦LAI的可行性, 本文以获取到的3个关键生育期(孕穗期、开花期和灌浆期)冬小麦无人机数码影像为数据源, 利用数字图像转换原理构建出10种数字图像特征参数, 并系统地分析了3个生育期内两个冬小麦品种在4种氮水平下的LAI与数字图像特征参数之间的关联性。结果表明, 在LAI随生育期发生变化的同时, 10种数字图像特征参数中R/(R+G+B)和本文提出的基于无人机数码影像红、绿、蓝通道DN值以及可见光大气阻抗植被指数(VARI)计算原理构建的数字图像特征参数UAV-based VARIRGB也有规律性变化, 说明冬小麦的施氮差异不仅对LAI有影响, 也对某些数字图像特征参数有一定影响; 在不同条件(品种、氮营养水平以及生育期)下的数字图像特征参数与LAI的相关性分析中, R/(R+G+B)和UAV-based VARIRGB与LAI显著相关。进而, 研究评价了R/(R+G+B)和UAV-based VARIRGB构建的LAI估测模型, 最终确定UAV-based VARIRGB为估测冬小麦LAI的最佳参数指标。结果表明UAV-based VARIRGB指数模型估测的LAI与实测LAI拟合性较好(R2=0.71, RMSE=0.8, P<0.01)。本研究证明将无人机数码影像应用于冬小麦LAI探测是可行的, 这也为高性价比无人机遥感系统的精准农业应用增添了新成果和经验。
2016, 24(6): 704-715.
摘要：
研究不同耕作措施下小麦玉米轮作农田N2O、CO2和CH4等温室气体的综合增温潜势, 有助于科学评价农业管理措施在减少温室气体排放和减缓全球变暖方面的作用, 为制定温室气体减排措施提供依据。基于2001年开始的位于华北太行山前平原中国科学院栾城农业生态系统试验站的不同耕作与秸秆还田方式定位试验, 应用静态箱/气相色谱法于2008年10月冬小麦播种时开始, 连续两个作物轮作年动态监测了秸秆整秸覆盖免耕播种(M1)、秸秆粉碎覆盖免耕(M2)、秸秆粉碎还田旋耕(X)、秸秆粉碎还田深翻耕(F)和无秸秆还田深翻耕(CK, 代表传统耕作方式)5种情况下冬小麦夏玉米轮作农田土壤N2O、CO2和CH4排放通量, 并估算其排放总量。试验期间同步记录每项农事活动机械燃油量、灌溉耗电量、施肥量, 依据燃油、耗电和单位肥料量的碳排放系数统一转换为等碳当量, 测定作物产量、地上部生物量, 估算农田碳截存量, 根据每个分支项对温室效应的作用估算了5个处理的综合增温潜势。结果表明, 华北小麦玉米轮作农田土壤是N2O和CO2的排放源, 是CH4的吸收汇, 每年M1、M2、X、F和CK农田土壤N2O排放总量依次为2.06 kg(N2O-N).hm-2、2.28 kg(N2O-N).hm-2、2.54 kg(N2O-N).hm-2、3.87 kg(N2O-N).hm-2和2.29 kg(N2O-N).hm-2, CO2排放总量依次为 6 904 kg(CO2-C).hm-2、7 351 kg(CO2-C).hm-2、8 873 kg(CO2-C).hm-2、9 065 kg(CO2-C).hm-2和7 425 kg(CO2-C).hm-2, CH4吸收量依次为2.50 kg(CH4-C).hm-2、1.77 kg(CH4-C).hm-2、1.33 kg(CH4-C).hm-2、1.38 kg(CH4-C).hm-2和1.57 kg(CH4-C).hm-2。M1和M2处理农田生态系统综合增温潜势(GWP)均为负值, 表明免耕情况下农田生态系统为大气的碳汇, 去除农事活动引起的直接或间接排放的等当量碳, 每年农田生态系统净截留碳947~1 070 kg(C).hm-2; 其他处理农田生态系统的GWP值均为正值, 表明温室气体是由系统向大气排放, CK、F和X每年向大气分别排放等当量碳3 364 kg(C).hm-2、989 kg(C).hm-2和343 kg(C).hm-2。故华北小麦玉米轮作体系中, 秸秆粉碎还田旋耕是最优化的耕作措施, 其温室效应相对较低, 而又能保证较高的经济产量。
研究不同耕作措施下小麦玉米轮作农田N2O、CO2和CH4等温室气体的综合增温潜势, 有助于科学评价农业管理措施在减少温室气体排放和减缓全球变暖方面的作用, 为制定温室气体减排措施提供依据。基于2001年开始的位于华北太行山前平原中国科学院栾城农业生态系统试验站的不同耕作与秸秆还田方式定位试验, 应用静态箱/气相色谱法于2008年10月冬小麦播种时开始, 连续两个作物轮作年动态监测了秸秆整秸覆盖免耕播种(M1)、秸秆粉碎覆盖免耕(M2)、秸秆粉碎还田旋耕(X)、秸秆粉碎还田深翻耕(F)和无秸秆还田深翻耕(CK, 代表传统耕作方式)5种情况下冬小麦夏玉米轮作农田土壤N2O、CO2和CH4排放通量, 并估算其排放总量。试验期间同步记录每项农事活动机械燃油量、灌溉耗电量、施肥量, 依据燃油、耗电和单位肥料量的碳排放系数统一转换为等碳当量, 测定作物产量、地上部生物量, 估算农田碳截存量, 根据每个分支项对温室效应的作用估算了5个处理的综合增温潜势。结果表明, 华北小麦玉米轮作农田土壤是N2O和CO2的排放源, 是CH4的吸收汇, 每年M1、M2、X、F和CK农田土壤N2O排放总量依次为2.06 kg(N2O-N).hm-2、2.28 kg(N2O-N).hm-2、2.54 kg(N2O-N).hm-2、3.87 kg(N2O-N).hm-2和2.29 kg(N2O-N).hm-2, CO2排放总量依次为 6 904 kg(CO2-C).hm-2、7 351 kg(CO2-C).hm-2、8 873 kg(CO2-C).hm-2、9 065 kg(CO2-C).hm-2和7 425 kg(CO2-C).hm-2, CH4吸收量依次为2.50 kg(CH4-C).hm-2、1.77 kg(CH4-C).hm-2、1.33 kg(CH4-C).hm-2、1.38 kg(CH4-C).hm-2和1.57 kg(CH4-C).hm-2。M1和M2处理农田生态系统综合增温潜势(GWP)均为负值, 表明免耕情况下农田生态系统为大气的碳汇, 去除农事活动引起的直接或间接排放的等当量碳, 每年农田生态系统净截留碳947~1 070 kg(C).hm-2; 其他处理农田生态系统的GWP值均为正值, 表明温室气体是由系统向大气排放, CK、F和X每年向大气分别排放等当量碳3 364 kg(C).hm-2、989 kg(C).hm-2和343 kg(C).hm-2。故华北小麦玉米轮作体系中, 秸秆粉碎还田旋耕是最优化的耕作措施, 其温室效应相对较低, 而又能保证较高的经济产量。
2016, 24(7): 874-882.
摘要：
水分不足是限制半干旱雨养作物生长的主要因素, 地表覆盖能够改善土壤的微环境, 从而显著提高作物的产量和水分利用效率。为明确西北半干旱雨养区不同保墒措施下旱地马铃薯的土壤水分特征及其对产量的影响, 于2014—2015年设置了玉米秸秆带状覆盖种植(T1)、半膜大垄(T2)、全膜双垄(T3)和露地平作(对照, CK) 4种栽培模式, 研究了玉米秸秆带状覆盖、地膜覆盖种植对马铃薯产量、土壤水分变化及其利用效率的影响。结果表明: 不同覆盖方式能有效改善马铃薯生育期0~200 cm土层土壤水分状况, 地膜覆盖对马铃薯生育前期土壤水分保蓄效果较好, 秸秆带状覆盖对生育中后期土壤水分状况的改善效果明显。与对照(CK)相比, 3种覆盖处理均提高了土壤含水量, 其中T1处理效果最好, 较CK提高2.8%~7.8%, 尤其在伏旱阶段的块茎形成期, 0~200 cm土层土壤含水量高于地膜覆盖处理。与CK相比, T1处理马铃薯产量提高10.5%~34.2%, 水分利用效率(WUE)提高8.9%~29.8%, 达108.9~134.0 kg·hm-2 ·mm-1, 商品薯率提高14.7%~38.8%, 达82.3%~92.2%。马铃薯产量与生育期耗水量(r=0.836**)呈显著正相关。T1的产量和商品薯率均显著高于T2和T3(P<0.05)。可见, 玉米秸秆带状覆盖具有显著的纳雨保墒作用, 促进马铃薯的生长发育, 增产效果显著。其推广应用可有效提高该区降水资源的利用效率, 实现马铃薯稳产高产, 可作为西北雨养农业区旱地马铃薯生产的高效栽培新模式。
水分不足是限制半干旱雨养作物生长的主要因素, 地表覆盖能够改善土壤的微环境, 从而显著提高作物的产量和水分利用效率。为明确西北半干旱雨养区不同保墒措施下旱地马铃薯的土壤水分特征及其对产量的影响, 于2014—2015年设置了玉米秸秆带状覆盖种植(T1)、半膜大垄(T2)、全膜双垄(T3)和露地平作(对照, CK) 4种栽培模式, 研究了玉米秸秆带状覆盖、地膜覆盖种植对马铃薯产量、土壤水分变化及其利用效率的影响。结果表明: 不同覆盖方式能有效改善马铃薯生育期0~200 cm土层土壤水分状况, 地膜覆盖对马铃薯生育前期土壤水分保蓄效果较好, 秸秆带状覆盖对生育中后期土壤水分状况的改善效果明显。与对照(CK)相比, 3种覆盖处理均提高了土壤含水量, 其中T1处理效果最好, 较CK提高2.8%~7.8%, 尤其在伏旱阶段的块茎形成期, 0~200 cm土层土壤含水量高于地膜覆盖处理。与CK相比, T1处理马铃薯产量提高10.5%~34.2%, 水分利用效率(WUE)提高8.9%~29.8%, 达108.9~134.0 kg·hm-2 ·mm-1, 商品薯率提高14.7%~38.8%, 达82.3%~92.2%。马铃薯产量与生育期耗水量(r=0.836**)呈显著正相关。T1的产量和商品薯率均显著高于T2和T3(P<0.05)。可见, 玉米秸秆带状覆盖具有显著的纳雨保墒作用, 促进马铃薯的生长发育, 增产效果显著。其推广应用可有效提高该区降水资源的利用效率, 实现马铃薯稳产高产, 可作为西北雨养农业区旱地马铃薯生产的高效栽培新模式。
Application of spatial viewshed analysis in classifying scenic forests along the Badaling Great Wall
2013, 21(9): 1157-1165.
doi: 10.3724/SP.J.1011.2013.01157
Abstract:
2019, 27(6): 845-859.
doi: 10.13930/j.cnki.cjea.180983
Abstract:
Editor-in-chief：LIU Changming
Competent Authorities：Chinese Academy of Sciences
Sponsored by：Institute of Genetics and Developmental Biology, Chinese Academy of Sciences; China Ecological Economics Society
Organizer：Institute of Genetics and Developmental Biology, Chinese Academy of SciencesChinese Society of Ecological Economics
ISSN 2096-6237
CN 13-1432/S
- Chinese core periodicals
- Core Chinese Sci-Tech Periodicals
- China's Top Science and Technology Periodicals
- Covered by Chinese Science Citation Database (CSCD)
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