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Measurement, spatial spillover and influencing factors of agricultural carbon emissions efficiency in China
WU Haoyue, HUANG Hanjiao, HE Yu, CHEN Wenkuan
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Effects of tillage and straw returning method on the distribution of carbon and nitrogen in soil aggregates
ZHANG Yuming, HU Chunsheng, CHEN Suying, WANG Yuying, LI Xiaoxin, DONG Wenxu, LIU Xiuping, PEI Lin, ZHANG Hui
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Relationship between policy incentives, ecological cognition, and organic fertilizer application by farmers: Based on a moderated mediation model
SANG Xiance, LUO Xiaofeng, HUANG Yanzhong, TANG Lin
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Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models
YANG Jie, XIE Baopeng, ZHANG Degang
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Effects of straw returning and fertilization on soil bacterial and fungal community structures and diversities in rice-wheat rotation soil
ZHANG Hanlin, BAI Naling, ZHENG Xianqing, LI Shuangxi, ZHANG Juanqin, ZHANG Haiyun, ZHOU Sheng, SUN Huifeng, LYU Weiguang
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2016 Vol. 24, No. 1
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2016, 24(1): 1-7.
doi: 10.13930/j.cnki.cjea.150566
Abstract:
Rice is an important food crop in China. Rice blast, a disease caused by ascomycetes (Magnaporthe oryzae), is one of most limiting factors of rice production in the country, which results in huge economic losses to the rice production each year. With the completion of whole genome sequencing of rice and M. oryzae, the interaction mechanism of rice and M. oryzae has become much clearer. Resistance to rice blast fungus can effectively prevent the invasion of pathogenic bacteria through the natural immune system of rice. Also pathogens can cause diseases in susceptible rice varieties by inhibiting innate immune system of rice. Outbreaks of rice blast and popular occur under three necessary conditions — susceptible rice variety, pathogenic bacteria and pathogenic meteorological factors. Thus the meteorological factors for the outbreak and epidemics of rice blast play an important role. Based on research achievements in recent years, this paper summarized the interaction mechanism of rice and M. oryzae from the pointing of pathogenic process of M. oryzae and rice resistance, discussed the effects of temperature, illumination, humidity and other meteorological factors on the pathogenesis of M. oryzae and disease resistance of rice. The paper further explored the molecular mechanism of invasion of rice blast epidemic caused by the factors, expecting to find the best ways for preventing and controlling rice blast. Finally, the paper provided theoretical evidences in support of proper prevention and treatment methods of rice blast.
Rice is an important food crop in China. Rice blast, a disease caused by ascomycetes (Magnaporthe oryzae), is one of most limiting factors of rice production in the country, which results in huge economic losses to the rice production each year. With the completion of whole genome sequencing of rice and M. oryzae, the interaction mechanism of rice and M. oryzae has become much clearer. Resistance to rice blast fungus can effectively prevent the invasion of pathogenic bacteria through the natural immune system of rice. Also pathogens can cause diseases in susceptible rice varieties by inhibiting innate immune system of rice. Outbreaks of rice blast and popular occur under three necessary conditions — susceptible rice variety, pathogenic bacteria and pathogenic meteorological factors. Thus the meteorological factors for the outbreak and epidemics of rice blast play an important role. Based on research achievements in recent years, this paper summarized the interaction mechanism of rice and M. oryzae from the pointing of pathogenic process of M. oryzae and rice resistance, discussed the effects of temperature, illumination, humidity and other meteorological factors on the pathogenesis of M. oryzae and disease resistance of rice. The paper further explored the molecular mechanism of invasion of rice blast epidemic caused by the factors, expecting to find the best ways for preventing and controlling rice blast. Finally, the paper provided theoretical evidences in support of proper prevention and treatment methods of rice blast.
2016, 24(1): 8-16.
doi: 10.13930/j.cnki.cjea.150740
Abstract:
Mineralization of soil organic carbon (SOC) is a vital link in carbon cycle in terrestrial ecosystems and has a significant effect on soil productivity and CO2 exchange in the soil-atmosphere system. Studies on the response of SOC mineralization and its temperature sensitivity to long-term fertilization could provide essential information for the understanding of SOC dynamics in semiarid agro-ecosystems. In this paper, we analyzed the characteristics of SOC mineralization for soils collected from legume-grain rotation systems with 27 years of application history of different fertilizers in the semiarid Loess Plateau of China. We also analyzed SOC mineralization sensitivity to temperature and its response to different fertilizations. The objective of the study was to build a deeper insight into how SOC mineralization responds to long-term fertilization in semiarid agro-ecosystems. The results showed that SOC mineralization rates were high at the initial stage and then slowly decreased at different temperature (15 ℃ and 25 ℃) and fertilization treatments. Fertilization and cultivation temperature significantly influenced SOC mineralization. Compared with the no fertilization treatment (control), long-term application of phosphorus (P), combined nitrogen and phosphorus (NP), and combined nitrogen, phosphorus manure (NPM) increased cumulative mineralized SOC (Cmin) by 41%, 85% and 89%, respectively, at 15 ℃, and by 7%, 46% and 77%, respectively, and 25 ℃. Also compared with control, P, NP and NPM application conditions decreased SOC mineralization sensitivity to temperature by 25%, 21% and 6%, respectively. Long-term fertilization changed the parameters of SOC mineralization, which varied with fertilizer type and cultivation temperature. SOC mineralization potential (Cp) of P, NP and NPM treatments increased by 29%, 65% and 48%, respectively, compared with that of control at 15 ℃. However, at 25 ℃, Cp increased by 2% under NP condition, increased by 21% under NPM condition, and decreased by 36% under P treatment compared with that under control. SOC mineralization constant (k) varied slightly at 15 ℃, but greatly increased due to fertilization at 25 ℃. Additionally at 25 ℃, cumulative Cmin and Cp were enhanced positively with increasing of both SOC and soil total nitrogen content. But at 15 ℃, Cmin and Cp were barely positively correlated with SOC and soil nitrogen. In conclusion, long-term fertilization increased SOC mineralization in legume-grain rotation systems in semiarid Loess Plateau, and decreased SOC mineralization sensitivity to temperature.
Mineralization of soil organic carbon (SOC) is a vital link in carbon cycle in terrestrial ecosystems and has a significant effect on soil productivity and CO2 exchange in the soil-atmosphere system. Studies on the response of SOC mineralization and its temperature sensitivity to long-term fertilization could provide essential information for the understanding of SOC dynamics in semiarid agro-ecosystems. In this paper, we analyzed the characteristics of SOC mineralization for soils collected from legume-grain rotation systems with 27 years of application history of different fertilizers in the semiarid Loess Plateau of China. We also analyzed SOC mineralization sensitivity to temperature and its response to different fertilizations. The objective of the study was to build a deeper insight into how SOC mineralization responds to long-term fertilization in semiarid agro-ecosystems. The results showed that SOC mineralization rates were high at the initial stage and then slowly decreased at different temperature (15 ℃ and 25 ℃) and fertilization treatments. Fertilization and cultivation temperature significantly influenced SOC mineralization. Compared with the no fertilization treatment (control), long-term application of phosphorus (P), combined nitrogen and phosphorus (NP), and combined nitrogen, phosphorus manure (NPM) increased cumulative mineralized SOC (Cmin) by 41%, 85% and 89%, respectively, at 15 ℃, and by 7%, 46% and 77%, respectively, and 25 ℃. Also compared with control, P, NP and NPM application conditions decreased SOC mineralization sensitivity to temperature by 25%, 21% and 6%, respectively. Long-term fertilization changed the parameters of SOC mineralization, which varied with fertilizer type and cultivation temperature. SOC mineralization potential (Cp) of P, NP and NPM treatments increased by 29%, 65% and 48%, respectively, compared with that of control at 15 ℃. However, at 25 ℃, Cp increased by 2% under NP condition, increased by 21% under NPM condition, and decreased by 36% under P treatment compared with that under control. SOC mineralization constant (k) varied slightly at 15 ℃, but greatly increased due to fertilization at 25 ℃. Additionally at 25 ℃, cumulative Cmin and Cp were enhanced positively with increasing of both SOC and soil total nitrogen content. But at 15 ℃, Cmin and Cp were barely positively correlated with SOC and soil nitrogen. In conclusion, long-term fertilization increased SOC mineralization in legume-grain rotation systems in semiarid Loess Plateau, and decreased SOC mineralization sensitivity to temperature.
2016, 24(1): 17-26.
doi: 10.13930/j.cnki.cjea.150744
Abstract:
In order to clarify the features of dry matter production and leaf function during post-silking stage in maize varieties with different low-nitrogen tolerance, a field experiment with 6 levels of nitrogen application rates [0 kg(N)hm-2 (B1)、90 kg(N)hm-2 (B2)、180 kg(N)hm-2 (B3)、270 kg(N)hm-2 (B4)、360 kg(N)hm-2 (B5), 450 kg(N)hm-2 (B6)] was conducted using low-nitrogen tolerant maize cultivar ‘Zhenghong 311’ and low-nitrogen sensitive maize cultivar ‘Xianyu 508’ as experimental materials. The results showed that nitrogen application significantly increased dry matter accumulation, leaf area index and leaf photosynthetic rate. It also alleviated the reductions of both chlorophyll and nitrogen contents of maize leaf at post-silking stage due to nitrogen deficiency, which was in turn reduced leaf C/N ratio at late growth stage, and increased maize yield. Dry matter accumulation, photosynthetic rate and leaf area index at post-silking stage and yield of low-nitrogen tolerant cultivar ‘Zhenghong 311’ increased by 30.5%, 9.2%, 35.0% and 8.8%, respectively, compared with those of low-nitrogen sensitive cultivar ‘Xianyu 508’. Chlorophyll content in leaves of ‘Zhenghong 311’ enhanced by 4.85% compared to that of ‘Xianyu508’ at post-silking stage. Low-nitrogen tolerant maize cultivar ‘Zhenghong 311’ maintained high chlorophyll content to ensure high dry matter production. There was no significant difference in leaf nitrogen content between two maize cultivars after silking stage. Compared with silking stage, however, leaf nitrogen content decreased by 31.5% for ‘Zhenghong 311’ and by 34.9% for ‘Xianyu 508’ at maturity stage. C/N ratio in leaf of ‘Xianyu 508’ was higher than that of ‘Zhenghong 311’ by 5.95% at post-silking stage. Compared with low-nitrogen sensitive cultivar ‘Xianyu 508’, low-nitrogen tolerant cultivar ‘Zhenghong 311’ kept higher photosynthetic rate and leaf area index during post-silking period, the amplitude of decline in both chlorophyll and nitrogen contents was alleviated, and C/N ratio in leaf kept lower level at later growth stage, all which were beneficial for prolonging leaf functional period, delaying leaf senescence, and increasing dry matter accumulation and yield of ‘Zhenghong 311’. In summary, nitrogen fertilizer effectively increased dry matter accumulation, leaf area index and grain yield. It reduced the increase of C/N ratio in leaf of ‘Zhenghong 311’. However, ‘Xianyu 508’ needed high nitrogen fertilization application to maintain effective leaf photosynthetic rate and nitrogen content.
In order to clarify the features of dry matter production and leaf function during post-silking stage in maize varieties with different low-nitrogen tolerance, a field experiment with 6 levels of nitrogen application rates [0 kg(N)hm-2 (B1)、90 kg(N)hm-2 (B2)、180 kg(N)hm-2 (B3)、270 kg(N)hm-2 (B4)、360 kg(N)hm-2 (B5), 450 kg(N)hm-2 (B6)] was conducted using low-nitrogen tolerant maize cultivar ‘Zhenghong 311’ and low-nitrogen sensitive maize cultivar ‘Xianyu 508’ as experimental materials. The results showed that nitrogen application significantly increased dry matter accumulation, leaf area index and leaf photosynthetic rate. It also alleviated the reductions of both chlorophyll and nitrogen contents of maize leaf at post-silking stage due to nitrogen deficiency, which was in turn reduced leaf C/N ratio at late growth stage, and increased maize yield. Dry matter accumulation, photosynthetic rate and leaf area index at post-silking stage and yield of low-nitrogen tolerant cultivar ‘Zhenghong 311’ increased by 30.5%, 9.2%, 35.0% and 8.8%, respectively, compared with those of low-nitrogen sensitive cultivar ‘Xianyu 508’. Chlorophyll content in leaves of ‘Zhenghong 311’ enhanced by 4.85% compared to that of ‘Xianyu508’ at post-silking stage. Low-nitrogen tolerant maize cultivar ‘Zhenghong 311’ maintained high chlorophyll content to ensure high dry matter production. There was no significant difference in leaf nitrogen content between two maize cultivars after silking stage. Compared with silking stage, however, leaf nitrogen content decreased by 31.5% for ‘Zhenghong 311’ and by 34.9% for ‘Xianyu 508’ at maturity stage. C/N ratio in leaf of ‘Xianyu 508’ was higher than that of ‘Zhenghong 311’ by 5.95% at post-silking stage. Compared with low-nitrogen sensitive cultivar ‘Xianyu 508’, low-nitrogen tolerant cultivar ‘Zhenghong 311’ kept higher photosynthetic rate and leaf area index during post-silking period, the amplitude of decline in both chlorophyll and nitrogen contents was alleviated, and C/N ratio in leaf kept lower level at later growth stage, all which were beneficial for prolonging leaf functional period, delaying leaf senescence, and increasing dry matter accumulation and yield of ‘Zhenghong 311’. In summary, nitrogen fertilizer effectively increased dry matter accumulation, leaf area index and grain yield. It reduced the increase of C/N ratio in leaf of ‘Zhenghong 311’. However, ‘Xianyu 508’ needed high nitrogen fertilization application to maintain effective leaf photosynthetic rate and nitrogen content.
2016, 24(1): 27-35.
doi: 10.13930/j.cnki.cjea.150707
Abstract:
A local experiment of lucerne-crop rotation system was conducted on dry farmlands of the Loess Plateau in Central Gansu Province to determine the distribution characteristics of soil aggregate stability and soil organic carbon. The experiment included six rotation patterns — lucerne-lucerne (LL), lucerne-fallow (LF), lucerne-wheat (LW), lucerne-corn (LC), lucerne- potato (LP) and lucerne-millet (LM). Soil aggregate characteristics and organic carbon content were investigated after crop harvest. The results showed that ≥0.25 mm aggregate was the dominant component of the mechanically stable aggregates of soil, which accounted for >72.17% of the mechanically stable aggregates. However, the <0.25 mm aggregates was the dominant component of the water stable aggregates, which exceeding 95.18% of the water stable aggregates. The content of the?≥0.25 mm aggregates of soil and its mean weight diameter (MWD) increased with increasing soil depth, while larger water stable aggregates content and MWD were irregularly changed. Compared with LL treatment, the ≥0.25 mm aggregates contents of LC and LP treatments increased by 5.94% and 1.12%, respectively, at soil depth of 030 cm. The MWD in LC treatment was the highest among all treatments. Soil organic carbon (SOC) content decreased with increasing soil depth in all rotation patterns. Compared with LL rotation pattern, SOC contents in LF, LC, LP and LM treatments all declined to different extents at 030 cm soil depth, especially, it significantly decreased by 18.68% in LP treatment. The correlation analysis indicated that SOC content had significantly positive relation with water stable soil aggregates of 25 mm, 12 mm, 0.51 mm, 0.250.5 mm and MWD, while it had significantly negative relation with <0.25 mm soil aggregate content. In conclusion, LC rotation pattern significantly increased the mechanical stability of soil aggregates. However, the effect of different rotation patterns on water stable soil aggregates was negligible. Furthermore, SOC content significantly influenced the formation and stability of water stable aggregate.
A local experiment of lucerne-crop rotation system was conducted on dry farmlands of the Loess Plateau in Central Gansu Province to determine the distribution characteristics of soil aggregate stability and soil organic carbon. The experiment included six rotation patterns — lucerne-lucerne (LL), lucerne-fallow (LF), lucerne-wheat (LW), lucerne-corn (LC), lucerne- potato (LP) and lucerne-millet (LM). Soil aggregate characteristics and organic carbon content were investigated after crop harvest. The results showed that ≥0.25 mm aggregate was the dominant component of the mechanically stable aggregates of soil, which accounted for >72.17% of the mechanically stable aggregates. However, the <0.25 mm aggregates was the dominant component of the water stable aggregates, which exceeding 95.18% of the water stable aggregates. The content of the?≥0.25 mm aggregates of soil and its mean weight diameter (MWD) increased with increasing soil depth, while larger water stable aggregates content and MWD were irregularly changed. Compared with LL treatment, the ≥0.25 mm aggregates contents of LC and LP treatments increased by 5.94% and 1.12%, respectively, at soil depth of 030 cm. The MWD in LC treatment was the highest among all treatments. Soil organic carbon (SOC) content decreased with increasing soil depth in all rotation patterns. Compared with LL rotation pattern, SOC contents in LF, LC, LP and LM treatments all declined to different extents at 030 cm soil depth, especially, it significantly decreased by 18.68% in LP treatment. The correlation analysis indicated that SOC content had significantly positive relation with water stable soil aggregates of 25 mm, 12 mm, 0.51 mm, 0.250.5 mm and MWD, while it had significantly negative relation with <0.25 mm soil aggregate content. In conclusion, LC rotation pattern significantly increased the mechanical stability of soil aggregates. However, the effect of different rotation patterns on water stable soil aggregates was negligible. Furthermore, SOC content significantly influenced the formation and stability of water stable aggregate.
2016, 24(1): 36-46.
doi: 10.13930/j.cnki.cjea.150554
Abstract:
A field experiment comprising of monoculture and intercropping of two crops (melon and sunflower) was conducted at three sunflower sowing times (at vine running, flowering and fruit expansion stages of melon) at three intercropping densities of each crop [high (24 975 plant·hm-2), medium (22 200 plant·hm-2) and low (19 980 plant·hm-2)] to study plant nitrogen accumulation and nitrogen use efficiency and to determine the relationship between solar energy utilization efficiency and nitrogen use efficiency. The results showed that intercropping significantly increased nitrogen accumulation and nitrogen use efficiency of melon, but reduced those of the sunflower. Under intercropping conditions, nitrogen accumulation of above-ground parts of melon was 195.08 kg·hm-2, increasing by 13.0% compared with that of monocultured melon (172.61 kg·hm-2). Nitrogen use efficiency and partial nitrogen productivity of intercropped melon significantly increased, respectively, by 40.5% and 55.4%, over those of monocultured melon. Nitrogen use efficiency and nitrogen partial productivity of sunflower under intercropping decreased, respectively, by 8.2% and 58.4% compared with those of monocultured sunflower, but nitrogen harvest index increased by 4.9%. Nitrogen use efficiency of intercropping system at three sunflower intercropping times (vine running, flowering and fruit expansion stages of melon) increased, respectively, by 43.5%, 12.5% and 59.8% over that of monoculture sunflower of the same sowing times. Also nitrogen use efficiency of intercropping system intercropped at fruit expansion period of melon increased by 6.7%, compared with average nitrogen use efficiency of monocultured melon. Partial nitrogen productivity of intercropped system with three intercropping times increased, respectively, by 6.5%, 32.1% and 40.4% compared with monocultured sunflower of the same sowing time, but decreased, respectively, by 22.5%, 10.1% and 34.3% compared with the average value for monoculturd melon. Nitrogen harvest index of intercropping system at three sunflower intercropping times decreased by 7.2%, 7.7% and 12.5%, respectively, compared with that of monocultured sunflower. Nitrogen utilization efficiencies of intercropping system at three intercropping densities reduced by 14.2% (high density), 20.4% (middle density) and 13.9% (low density), respectively, compared with that of monocultured melon at the same corresponding density, but increased, respectively, by 25.2%, 20.0% and 9.5% compared with the average value of monocultured sunflower. Partial nitrogen productivity of intercropping system with three intercropping densities decreased, respectively, by 29.6%, 15.6% and 21.1% compared with the corresponding treatments of monocultured melon. Nitrogen harvest index of intercropping system at high and low intercropping densities increased, respectively, by 2.7% and 1.4% compared with average nitrogen harvest index of monocultured sunflower, but decreased by 7.6% at medium density. There was significantly positive correlation between nitrogen use efficiency and light use efficiency of melon under intercropping system, but not with sunflower. The results suggested that fruit expansion period of melon was the most suitable intercropping time of sunflower and 40 cm plant spacing was the optimum planting density in melon-sunflower intercropping system, which resulting in high nitrogen use efficiency.
A field experiment comprising of monoculture and intercropping of two crops (melon and sunflower) was conducted at three sunflower sowing times (at vine running, flowering and fruit expansion stages of melon) at three intercropping densities of each crop [high (24 975 plant·hm-2), medium (22 200 plant·hm-2) and low (19 980 plant·hm-2)] to study plant nitrogen accumulation and nitrogen use efficiency and to determine the relationship between solar energy utilization efficiency and nitrogen use efficiency. The results showed that intercropping significantly increased nitrogen accumulation and nitrogen use efficiency of melon, but reduced those of the sunflower. Under intercropping conditions, nitrogen accumulation of above-ground parts of melon was 195.08 kg·hm-2, increasing by 13.0% compared with that of monocultured melon (172.61 kg·hm-2). Nitrogen use efficiency and partial nitrogen productivity of intercropped melon significantly increased, respectively, by 40.5% and 55.4%, over those of monocultured melon. Nitrogen use efficiency and nitrogen partial productivity of sunflower under intercropping decreased, respectively, by 8.2% and 58.4% compared with those of monocultured sunflower, but nitrogen harvest index increased by 4.9%. Nitrogen use efficiency of intercropping system at three sunflower intercropping times (vine running, flowering and fruit expansion stages of melon) increased, respectively, by 43.5%, 12.5% and 59.8% over that of monoculture sunflower of the same sowing times. Also nitrogen use efficiency of intercropping system intercropped at fruit expansion period of melon increased by 6.7%, compared with average nitrogen use efficiency of monocultured melon. Partial nitrogen productivity of intercropped system with three intercropping times increased, respectively, by 6.5%, 32.1% and 40.4% compared with monocultured sunflower of the same sowing time, but decreased, respectively, by 22.5%, 10.1% and 34.3% compared with the average value for monoculturd melon. Nitrogen harvest index of intercropping system at three sunflower intercropping times decreased by 7.2%, 7.7% and 12.5%, respectively, compared with that of monocultured sunflower. Nitrogen utilization efficiencies of intercropping system at three intercropping densities reduced by 14.2% (high density), 20.4% (middle density) and 13.9% (low density), respectively, compared with that of monocultured melon at the same corresponding density, but increased, respectively, by 25.2%, 20.0% and 9.5% compared with the average value of monocultured sunflower. Partial nitrogen productivity of intercropping system with three intercropping densities decreased, respectively, by 29.6%, 15.6% and 21.1% compared with the corresponding treatments of monocultured melon. Nitrogen harvest index of intercropping system at high and low intercropping densities increased, respectively, by 2.7% and 1.4% compared with average nitrogen harvest index of monocultured sunflower, but decreased by 7.6% at medium density. There was significantly positive correlation between nitrogen use efficiency and light use efficiency of melon under intercropping system, but not with sunflower. The results suggested that fruit expansion period of melon was the most suitable intercropping time of sunflower and 40 cm plant spacing was the optimum planting density in melon-sunflower intercropping system, which resulting in high nitrogen use efficiency.
2016, 24(1): 47-55.
doi: 10.13930/j.cnki.cjea.150679
Abstract:
In order to deal with the production problems associated with low temperature stress in winter and early spring, continuous cropping obstacles, low yields and low utilization efficiencies of water and fertilizer in solar greenhouses in North China, a novel cultivation method named ‘soil ridge substrate-embedded cultivation’ (SRSC) was designed and its performance was investigated. An investigation on root zone temperature of sweet pepper seedlings in two types of SRSC patterns [SRSC-P (polyethylene groove embedded in soil ridge) and SRSC-W (plastic film with wire mesh as support embedded in soil ridge)], SR (soil ridge) and NPG (naked polyethylene groove) were conducted in early spring. The results showed that the dynamic changes of ridge root zone temperatures were significantly positively correlated with both inside and outside temperatures of greenhouse. Moreover, daily mean temperatures inside greenhouse and in ridge root zone were increased by 8.07 ℃ and 10.93 ℃, respectively, than temperature outside greenhouse. The effect of greenhouse was more remarkable at night, temperatures inside greenhouse and in ridge root zone enhanced by 9.9 ℃ and 14.81 ℃, respectively, compared with outside temperature. Based on the data analysis, the performance of root zone temperature in terms of preservation of SRSC-W was better than that of SR and SRSC-P at night. And average night temperature were increased by 1.34 ℃ and 0.52 ℃, respectively, compared with those of SR and SRSC-P. The highest root zone temperatures of SR, SRSC-P, NPG and SRSC-W were 28.06 ℃, 27.21 ℃, 29.93 ℃ and 26.05 ℃, respectively, at daytime. This suggested that SRSC-W had the best buffering capacity for high temperature while NPG had the worst buffering capacity. The performance of SRSC in terms of heat storage and preservation under cloudy conditions was worse than that under sunny conditions. Root zone temperature in ridge center of SR was higher than that in lateral ridge at both daytime and nighttime. On the contrary, SRSC-P and SRSC-W had higher lateral temperatures in the daytime and higher center temperature at night. Root zone temperature in north part of ridge was higher than that of south part, and temperature difference was the smallest between south and north under SRSC-W condition. In addition, the lag time for dynamic change in root zone temperature in ridge center was the longest under SRSC-W condition due to powerful temperature buffer capacity. In short, the effect of preservation temperature in root zone of SRSC-W was the best with strongest temperature buffer capacity during low temperature period among all treatments. SRSC-W had a broad prospect for application with low cost and most stable performance of heat storage and preservation.
In order to deal with the production problems associated with low temperature stress in winter and early spring, continuous cropping obstacles, low yields and low utilization efficiencies of water and fertilizer in solar greenhouses in North China, a novel cultivation method named ‘soil ridge substrate-embedded cultivation’ (SRSC) was designed and its performance was investigated. An investigation on root zone temperature of sweet pepper seedlings in two types of SRSC patterns [SRSC-P (polyethylene groove embedded in soil ridge) and SRSC-W (plastic film with wire mesh as support embedded in soil ridge)], SR (soil ridge) and NPG (naked polyethylene groove) were conducted in early spring. The results showed that the dynamic changes of ridge root zone temperatures were significantly positively correlated with both inside and outside temperatures of greenhouse. Moreover, daily mean temperatures inside greenhouse and in ridge root zone were increased by 8.07 ℃ and 10.93 ℃, respectively, than temperature outside greenhouse. The effect of greenhouse was more remarkable at night, temperatures inside greenhouse and in ridge root zone enhanced by 9.9 ℃ and 14.81 ℃, respectively, compared with outside temperature. Based on the data analysis, the performance of root zone temperature in terms of preservation of SRSC-W was better than that of SR and SRSC-P at night. And average night temperature were increased by 1.34 ℃ and 0.52 ℃, respectively, compared with those of SR and SRSC-P. The highest root zone temperatures of SR, SRSC-P, NPG and SRSC-W were 28.06 ℃, 27.21 ℃, 29.93 ℃ and 26.05 ℃, respectively, at daytime. This suggested that SRSC-W had the best buffering capacity for high temperature while NPG had the worst buffering capacity. The performance of SRSC in terms of heat storage and preservation under cloudy conditions was worse than that under sunny conditions. Root zone temperature in ridge center of SR was higher than that in lateral ridge at both daytime and nighttime. On the contrary, SRSC-P and SRSC-W had higher lateral temperatures in the daytime and higher center temperature at night. Root zone temperature in north part of ridge was higher than that of south part, and temperature difference was the smallest between south and north under SRSC-W condition. In addition, the lag time for dynamic change in root zone temperature in ridge center was the longest under SRSC-W condition due to powerful temperature buffer capacity. In short, the effect of preservation temperature in root zone of SRSC-W was the best with strongest temperature buffer capacity during low temperature period among all treatments. SRSC-W had a broad prospect for application with low cost and most stable performance of heat storage and preservation.
2016, 24(1): 56-63.
doi: 10.13930/j.cnki.cjea.150820
Abstract:
Crop root length and soil moisture distribution are important determinants of crop root water uptake potential. Crop root length changes with growth stage, which also requires changes in soil moisture environment. Therefore, establishing a root growth model to predict crop root growth conditions under normal water use has theoretical and application significance regarding the determination of irrigation quota and soil moisture environment indicators, which are required to design appropriate local irrigation technology. However, current root growth simulating models are more suitable for the determina tion of irrigation quotas of whole irrigation technology. These models, which are mostly statistical, can not completely reflect the relational mechanisms of the growth of plant root system, crop water use and soil moisture environment. In view of the above and, a root-canopy water balance combined with crop coefficient vs. leaf area relationship model, root length density distribution function and root water uptake efficiency function, a cotton root growth model was developed based on dynamic programming theory and verified by experimental results of a barrel-cultivated cotton. The main results of the study showed that the model well accounted for the effects of root growth factors such as soil moisture environment, atmospheric transpiration rate and leaf area, which revealed to a certain extent the mechanism of crop water use due to root growth. The growth characteristics of cotton root length simulated by the model were consistent with measured dates in the barrel experiment. When multi-year average monthly mean reference evapotranspiration (ET0) was used as input condition, the overall error of the simulation result was 15.41%. Therefore the model was applicable in engineering designs. Based on sensitivity analysis, the established model well reflected the synchronization between the growth of cotton root and leaf, as well as the water balance between root and leaf after entering the reproductive period. The sensitivity of cotton root growth to changes in soil moisture environment was higher than to changes in leaf area, reflecting the processes of cotton root growth and the feasibility of the modeling method. The research significantly improved the design theory of irrigation systems for the development of localized irrigation technology.
Crop root length and soil moisture distribution are important determinants of crop root water uptake potential. Crop root length changes with growth stage, which also requires changes in soil moisture environment. Therefore, establishing a root growth model to predict crop root growth conditions under normal water use has theoretical and application significance regarding the determination of irrigation quota and soil moisture environment indicators, which are required to design appropriate local irrigation technology. However, current root growth simulating models are more suitable for the determina tion of irrigation quotas of whole irrigation technology. These models, which are mostly statistical, can not completely reflect the relational mechanisms of the growth of plant root system, crop water use and soil moisture environment. In view of the above and, a root-canopy water balance combined with crop coefficient vs. leaf area relationship model, root length density distribution function and root water uptake efficiency function, a cotton root growth model was developed based on dynamic programming theory and verified by experimental results of a barrel-cultivated cotton. The main results of the study showed that the model well accounted for the effects of root growth factors such as soil moisture environment, atmospheric transpiration rate and leaf area, which revealed to a certain extent the mechanism of crop water use due to root growth. The growth characteristics of cotton root length simulated by the model were consistent with measured dates in the barrel experiment. When multi-year average monthly mean reference evapotranspiration (ET0) was used as input condition, the overall error of the simulation result was 15.41%. Therefore the model was applicable in engineering designs. Based on sensitivity analysis, the established model well reflected the synchronization between the growth of cotton root and leaf, as well as the water balance between root and leaf after entering the reproductive period. The sensitivity of cotton root growth to changes in soil moisture environment was higher than to changes in leaf area, reflecting the processes of cotton root growth and the feasibility of the modeling method. The research significantly improved the design theory of irrigation systems for the development of localized irrigation technology.
2016, 24(1): 64-73.
doi: 10.13930/j.cnki.cjea.150678
Abstract:
In recent years, drip irrigation technology has been widely used in Xinjiang. This has especially been the case for high-intensity crops like wheat, regarded as a revolution in irrigation technology. Despite this, problems have persisted in the use of drip irrigation technology in field production such as high amounts of irrigation and increased irrigation times. Based on the problems of drip irrigation technology in Xinjiang, field experiments were conducted in Yining County, the northern region of Xinjiang, to identify the effects of different amounts of drip irrigation on the micro-climate and yield of winter wheat, and to provided reference for design of optimal drip irrigation amount of winter wheat. Three amounts of drip irrigation, 3 000 m-3·hm-2 (TA), 3 750 m-3·hm-2 (TB) and 4 500 m-3·hm-2 (TC), were set in a randomized block experimental design. Different indicators were observed under different treatments, including soil temperature, canopy temperature, canopy humidity, atmosphere CO2 concentration (Ca), soil evaporation, as well as leaf intercellular CO2 concentration (Ci) leaf, yield and yield components of wheat. The results showed that increasing amount of irrigation remarkably decreased soil temperature at the late growth stage of winter wheat. There were differences in temperature among the treatments, with 1.09 ℃, 1.61 ℃ and 0.52 ℃ differences, respectively, between TA and TB, TA and TC, and TB and TC treatments. With increasing irrigation, canopy temperature of wheat decreased whereas canopy humidity increased. The differences in the highest canopy temperature reached 3.68 ℃ between TA and TC. Both soil evaporation and Ci initially increased and then decreased, while Ca decreased throughout the growth stage with increasing drip irrigation. Yield initially decreased and then increase with increasing irrigation volume. It reached 8 971.66 kg·hm-2 under TB condition, which was 20.55% higher than that of TA and 6.86% higher than that of TC. Also a significant negative correlation was noted between soil temperature and yield, canopy temperature and yield, and Ci and yield. However, there was a strong positive correlation between canopy humidity and irrigation. It was therefore recommended that 3 750 m-3·hm-2 was the appropriate irrigation quantity for winter wheat in northern Xinjiang. This provided theoretical and practical bases for the development of a proper drip irrigation technology in the northern area of Xinjiang.
In recent years, drip irrigation technology has been widely used in Xinjiang. This has especially been the case for high-intensity crops like wheat, regarded as a revolution in irrigation technology. Despite this, problems have persisted in the use of drip irrigation technology in field production such as high amounts of irrigation and increased irrigation times. Based on the problems of drip irrigation technology in Xinjiang, field experiments were conducted in Yining County, the northern region of Xinjiang, to identify the effects of different amounts of drip irrigation on the micro-climate and yield of winter wheat, and to provided reference for design of optimal drip irrigation amount of winter wheat. Three amounts of drip irrigation, 3 000 m-3·hm-2 (TA), 3 750 m-3·hm-2 (TB) and 4 500 m-3·hm-2 (TC), were set in a randomized block experimental design. Different indicators were observed under different treatments, including soil temperature, canopy temperature, canopy humidity, atmosphere CO2 concentration (Ca), soil evaporation, as well as leaf intercellular CO2 concentration (Ci) leaf, yield and yield components of wheat. The results showed that increasing amount of irrigation remarkably decreased soil temperature at the late growth stage of winter wheat. There were differences in temperature among the treatments, with 1.09 ℃, 1.61 ℃ and 0.52 ℃ differences, respectively, between TA and TB, TA and TC, and TB and TC treatments. With increasing irrigation, canopy temperature of wheat decreased whereas canopy humidity increased. The differences in the highest canopy temperature reached 3.68 ℃ between TA and TC. Both soil evaporation and Ci initially increased and then decreased, while Ca decreased throughout the growth stage with increasing drip irrigation. Yield initially decreased and then increase with increasing irrigation volume. It reached 8 971.66 kg·hm-2 under TB condition, which was 20.55% higher than that of TA and 6.86% higher than that of TC. Also a significant negative correlation was noted between soil temperature and yield, canopy temperature and yield, and Ci and yield. However, there was a strong positive correlation between canopy humidity and irrigation. It was therefore recommended that 3 750 m-3·hm-2 was the appropriate irrigation quantity for winter wheat in northern Xinjiang. This provided theoretical and practical bases for the development of a proper drip irrigation technology in the northern area of Xinjiang.
2016, 24(1): 74-80.
doi: 10.13930/j.cnki.cjea.150579
Abstract:
In the past two decades, the eddy covariance technique has been used as a normalized measure method of exchange of CO2, water vapor and heat between vegetation and the atmosphere. To understand the variation characteristics of CO2, water vapor and heat fluxes of winter wheat/summer maize rotation system, an experiment was conducted in the period from June 2013 to June 2014 at Qingdao Modern Agricultural Demonstration Farm of Qingdao Agricultural University. The CO2, water vapor and heat fluxes were measured during both winter wheat and summer maize growing seasons using the eddy covariance method and the values corrected by two density correction methods (WPL correction and Liu correction), and then the difference between the two methods compared. An energy balance closure was also computed during bare and vegetation cover periods of both winter wheat and summer maize based on the two density correction methods. It was found that both of the two methods (WPL correction and Liu correction) increased the amount of latent heat flux. WPL correction method increased latent heat flux by about 6% for summer maize season and 2% for winter wheat season, while Liu correction method increased latent heat flux by less than 1% for summer maize season and about 2% for winter wheat season. WPL correction method reduced the amount of CO2 flux by less than 3% for summer maize and 4% for winter wheat. Also the Liu correction method reduced the amount of CO2 by about 2% for summer maize and 3% for winter wheat. There was little difference (about 1%) between the two correction methods for the correction of both latent heat and CO2 fluxes. The two correction methods had the potential to increase energy balance closure. WPL correction obviously increased energy balance closure by about 2.53%9.76% for bare soil, by 4.05% for summer maize and by 1.35% for winter wheat. Then Liu correction increased energy balance closure by less than 2.53% for bare soil and 1.35% for both summer maize and winter wheat seasons. This suggested that the degree of correction by WPL method was greater than that by Liu method. Energy balance closure during bare soil period was obviously higher than that during vegetation cover period. The order of the energy balance closure was: bare soilⅠ(before maize seed emergency) > bare soil Ⅱ (before winter wheat seed emergency) > summer maize vegetation period > winter wheat vegetation period.
In the past two decades, the eddy covariance technique has been used as a normalized measure method of exchange of CO2, water vapor and heat between vegetation and the atmosphere. To understand the variation characteristics of CO2, water vapor and heat fluxes of winter wheat/summer maize rotation system, an experiment was conducted in the period from June 2013 to June 2014 at Qingdao Modern Agricultural Demonstration Farm of Qingdao Agricultural University. The CO2, water vapor and heat fluxes were measured during both winter wheat and summer maize growing seasons using the eddy covariance method and the values corrected by two density correction methods (WPL correction and Liu correction), and then the difference between the two methods compared. An energy balance closure was also computed during bare and vegetation cover periods of both winter wheat and summer maize based on the two density correction methods. It was found that both of the two methods (WPL correction and Liu correction) increased the amount of latent heat flux. WPL correction method increased latent heat flux by about 6% for summer maize season and 2% for winter wheat season, while Liu correction method increased latent heat flux by less than 1% for summer maize season and about 2% for winter wheat season. WPL correction method reduced the amount of CO2 flux by less than 3% for summer maize and 4% for winter wheat. Also the Liu correction method reduced the amount of CO2 by about 2% for summer maize and 3% for winter wheat. There was little difference (about 1%) between the two correction methods for the correction of both latent heat and CO2 fluxes. The two correction methods had the potential to increase energy balance closure. WPL correction obviously increased energy balance closure by about 2.53%9.76% for bare soil, by 4.05% for summer maize and by 1.35% for winter wheat. Then Liu correction increased energy balance closure by less than 2.53% for bare soil and 1.35% for both summer maize and winter wheat seasons. This suggested that the degree of correction by WPL method was greater than that by Liu method. Energy balance closure during bare soil period was obviously higher than that during vegetation cover period. The order of the energy balance closure was: bare soilⅠ(before maize seed emergency) > bare soil Ⅱ (before winter wheat seed emergency) > summer maize vegetation period > winter wheat vegetation period.
2016, 24(1): 81-89.
doi: 10.13930/j.cnki.cjea.150564
Abstract:
The ecological consequences of the changes in ecosystem functions caused by land use change have attracted more attention in recent years. However, less study has focused on the relationship between biodiversity and ecosystem function. Agroforest ecosystem is the combination of agriculture and forestry for management purposes. As an important model, agroforestry has vital ecological benefits for land use substantial development. Agroforestry has been considered to support more species survival and higher biodiversity. Lac insects (Kerria spp.) as well as their excrement are important resource insects widely used in many fields including food, medicine and military industry. Lac-corn agroforestry ecosystem is popular pattern of lac production in mountain areas of Southwest China where lac production accounts for a good fraction of the income of farmers’ households. However, there is less research on the functional groups of arthropods in lac-corn agroforestry. Ants (Hymenoptera: Formicidae) are widely distributed in many terrestrial ecosystems. They can be used as indicator for evaluating environmental changes and ecosystem health because they are sensitive to disturbances in important functions of ecosystem. Studies have shown that functional groups constitute a useful method of predicting the response of ant communities to disturbances and environmental changes. This study determined the effects of lac-corn agroforest ecosystem on the diversity and functional groups of ground-dwelling ant communities and the role of lac-corn agroforestry ecosystem in ant diversity and ecosystem function protection. A research was conducted using pitfall traps on ground-dwelling ant communities in lac plantation, lac-corn agroforest ecosystem and cornfield in Lüchun County. A total of 11 781 individual ants were collected, belonging to 78 species, 37 genera and 7 sub-families. Lac-corn agroforest ecosystem had higher species and rare species numbers of ground-dwelling ant communities. In lac-corn agroforest ecosystem, the numbers species and rare species increased by 41% and 85%, respectively, compared with cornfield. Ant abundance in lac-corn agroforest ecosystem was significantly higher than that in lac plantation and cornfield. Ant abundance, ACE of ant in lac-corn agroforest ecosystem and lac plantation were significantly higher those of cornfield. Ant community structure of lac-corn agroforest ecosystem was similar to that of lac plantation, but dissimilar compared with cornfield. There were differences of species compositions and indicator species of the three sites. Paratrechina vividula and Pheidole yeensis were dominant species in cornfield, Aphaenogaster beccarii in lac plantation, and then Monomorium chinensis, M. orientale, Crematogaster rogenhoferi, Polyrhachis proxima and Cardiocondyla wroughtonii in lac-corn agroforest ecosystem were dominant species. Iridomyrmex anceps and P. yeensis were indicator species for cornfield, Dolichoderus incises, Lepisiota xichangensis and M. chinensis were indicator species for lac-corn agroforest ecosystem, and then A. feae, C. ferrarii, Tetramorium aptum, A. beccarii, and Pseudolasius silvestrii were indicator species for lac plantation. The proportions of different functional groups of ants in lac-corn agroforest ecosystem were in between lac plantation and cornfield. Species richness, abundance and proportions of Opportunists, Subordinate Camponotini, Cryptic Species and Climate Specialists in lac-corn agroforest ecosystem were higher than those in cornfield. Honeydew secretion by lac insects increased ant species richness and abundance in lac-corn agroforest ecosystem and lac plantation. Lac plantation and lac-corn agroforestry with more complex habitat supported more arthropods survival. Lac-corn agroforest ecosystem limited biodiversity loss caused by disturbances. It had positive effects on the protection of ground-dwelling ants and was a better sustainable development model for balancing the contradiction between environmental protection and economic development.
The ecological consequences of the changes in ecosystem functions caused by land use change have attracted more attention in recent years. However, less study has focused on the relationship between biodiversity and ecosystem function. Agroforest ecosystem is the combination of agriculture and forestry for management purposes. As an important model, agroforestry has vital ecological benefits for land use substantial development. Agroforestry has been considered to support more species survival and higher biodiversity. Lac insects (Kerria spp.) as well as their excrement are important resource insects widely used in many fields including food, medicine and military industry. Lac-corn agroforestry ecosystem is popular pattern of lac production in mountain areas of Southwest China where lac production accounts for a good fraction of the income of farmers’ households. However, there is less research on the functional groups of arthropods in lac-corn agroforestry. Ants (Hymenoptera: Formicidae) are widely distributed in many terrestrial ecosystems. They can be used as indicator for evaluating environmental changes and ecosystem health because they are sensitive to disturbances in important functions of ecosystem. Studies have shown that functional groups constitute a useful method of predicting the response of ant communities to disturbances and environmental changes. This study determined the effects of lac-corn agroforest ecosystem on the diversity and functional groups of ground-dwelling ant communities and the role of lac-corn agroforestry ecosystem in ant diversity and ecosystem function protection. A research was conducted using pitfall traps on ground-dwelling ant communities in lac plantation, lac-corn agroforest ecosystem and cornfield in Lüchun County. A total of 11 781 individual ants were collected, belonging to 78 species, 37 genera and 7 sub-families. Lac-corn agroforest ecosystem had higher species and rare species numbers of ground-dwelling ant communities. In lac-corn agroforest ecosystem, the numbers species and rare species increased by 41% and 85%, respectively, compared with cornfield. Ant abundance in lac-corn agroforest ecosystem was significantly higher than that in lac plantation and cornfield. Ant abundance, ACE of ant in lac-corn agroforest ecosystem and lac plantation were significantly higher those of cornfield. Ant community structure of lac-corn agroforest ecosystem was similar to that of lac plantation, but dissimilar compared with cornfield. There were differences of species compositions and indicator species of the three sites. Paratrechina vividula and Pheidole yeensis were dominant species in cornfield, Aphaenogaster beccarii in lac plantation, and then Monomorium chinensis, M. orientale, Crematogaster rogenhoferi, Polyrhachis proxima and Cardiocondyla wroughtonii in lac-corn agroforest ecosystem were dominant species. Iridomyrmex anceps and P. yeensis were indicator species for cornfield, Dolichoderus incises, Lepisiota xichangensis and M. chinensis were indicator species for lac-corn agroforest ecosystem, and then A. feae, C. ferrarii, Tetramorium aptum, A. beccarii, and Pseudolasius silvestrii were indicator species for lac plantation. The proportions of different functional groups of ants in lac-corn agroforest ecosystem were in between lac plantation and cornfield. Species richness, abundance and proportions of Opportunists, Subordinate Camponotini, Cryptic Species and Climate Specialists in lac-corn agroforest ecosystem were higher than those in cornfield. Honeydew secretion by lac insects increased ant species richness and abundance in lac-corn agroforest ecosystem and lac plantation. Lac plantation and lac-corn agroforestry with more complex habitat supported more arthropods survival. Lac-corn agroforest ecosystem limited biodiversity loss caused by disturbances. It had positive effects on the protection of ground-dwelling ants and was a better sustainable development model for balancing the contradiction between environmental protection and economic development.
2016, 24(1): 90-97.
doi: 10.13930/j.cnki.cjea.150599
Abstract:
Application of biological agents to improve saline soil is a relatively fast, economical, simple method with long-term effectiveness. Trichoderma spp. are free-living fungi that are highly active in interaction among root, soil and foliar environments. Biological agents application in agricultural systems is a potential method to ameliorate saline soil, eventually benefiting the environment or ecosystem by regulating soil physical and chemical properties and microbial population. In this study, broadcast granule preparation of Trichoderma agent (containing at least 1×107 colony-forming units of active ingredients for per gram dry weight) was applied to soil of moderately saline coastal platform fields to explore effect of Trichoderma agent on soil properties of moderately saline coastal platform field. Arable layers soils were sampled, which included moderately saline coastal platform field with (T1010) and without (CK) Trichoderma agent under peanut cropping (sandy loam soil with salt content of 2.99 g·kg-1), flood land in coastal saline area (sandy loam soil with salt content of 26.19 g·kg-1), reclaimed field in coastal slight saline area under continuous cotton cropping (light loam soil with salt content of 1.75 g·kg-1), non-saline solar- greenhouse soil under continuous tomato cropping (loam soil with salt content of 0.98 g·kg-1). All the plot samples were repeated four times, and the physical, chemical and biological properties tested in laboratory. The results showed that Trichoderma agent amended soil physical properties. Compared with CK, T1010 increased soil compaction by 177.04%, content of water stable aggregate of ≥0.25 mm by 265.78%, soil moisture content by 320.83%. In this study, soil chemical properties also changed. The contents of nitrogen, phosphorus, potassium and organic matter increased by 96.14%, 42.17%, 105.65% and 63.79%, respectively, under T1010 compared with those under CK. Under T1010, soil bacteria, actinomyce, fungi and azotobacters amounts increased by 170.95%, 82.68%, 152.17% and 471.93%, respectively, compared with those under CK. Beneficial properties to plants growth (e.g., soil compaction, ≥0.25 mm water stable aggregate, organic matter, microbial amount) of moderately saline coastal platform soils with Trichoderma agent (T1010) increased, respectively, by 1.53, 2.11, 3.20 and 28.33 times over that of flood land in coastal saline area. On the contrary, harmful property to plants growth, water soluble salts, reduced by 96.60%. Properties (such as soil compaction, porosity, moisture, contents of phosphorus and organic matter, and microbial amounts) of Trichoderma-amending moderately saline coastal soils were not significantly different from that of slightly saline coastal alkali soils. Reduced bulk density or increased porosity of moderately coastal saline platform fields with Trichoderma were close to that of the non-saline solar-greenhouse soils. Application of microbiological agents effectively improved soil properties of moderately saline coastal platform fields and ameliorated the ecological environment by enhancing soil aggregate structure, increasing soil nutrient and beneficial microorganisms amount.
Application of biological agents to improve saline soil is a relatively fast, economical, simple method with long-term effectiveness. Trichoderma spp. are free-living fungi that are highly active in interaction among root, soil and foliar environments. Biological agents application in agricultural systems is a potential method to ameliorate saline soil, eventually benefiting the environment or ecosystem by regulating soil physical and chemical properties and microbial population. In this study, broadcast granule preparation of Trichoderma agent (containing at least 1×107 colony-forming units of active ingredients for per gram dry weight) was applied to soil of moderately saline coastal platform fields to explore effect of Trichoderma agent on soil properties of moderately saline coastal platform field. Arable layers soils were sampled, which included moderately saline coastal platform field with (T1010) and without (CK) Trichoderma agent under peanut cropping (sandy loam soil with salt content of 2.99 g·kg-1), flood land in coastal saline area (sandy loam soil with salt content of 26.19 g·kg-1), reclaimed field in coastal slight saline area under continuous cotton cropping (light loam soil with salt content of 1.75 g·kg-1), non-saline solar- greenhouse soil under continuous tomato cropping (loam soil with salt content of 0.98 g·kg-1). All the plot samples were repeated four times, and the physical, chemical and biological properties tested in laboratory. The results showed that Trichoderma agent amended soil physical properties. Compared with CK, T1010 increased soil compaction by 177.04%, content of water stable aggregate of ≥0.25 mm by 265.78%, soil moisture content by 320.83%. In this study, soil chemical properties also changed. The contents of nitrogen, phosphorus, potassium and organic matter increased by 96.14%, 42.17%, 105.65% and 63.79%, respectively, under T1010 compared with those under CK. Under T1010, soil bacteria, actinomyce, fungi and azotobacters amounts increased by 170.95%, 82.68%, 152.17% and 471.93%, respectively, compared with those under CK. Beneficial properties to plants growth (e.g., soil compaction, ≥0.25 mm water stable aggregate, organic matter, microbial amount) of moderately saline coastal platform soils with Trichoderma agent (T1010) increased, respectively, by 1.53, 2.11, 3.20 and 28.33 times over that of flood land in coastal saline area. On the contrary, harmful property to plants growth, water soluble salts, reduced by 96.60%. Properties (such as soil compaction, porosity, moisture, contents of phosphorus and organic matter, and microbial amounts) of Trichoderma-amending moderately saline coastal soils were not significantly different from that of slightly saline coastal alkali soils. Reduced bulk density or increased porosity of moderately coastal saline platform fields with Trichoderma were close to that of the non-saline solar-greenhouse soils. Application of microbiological agents effectively improved soil properties of moderately saline coastal platform fields and ameliorated the ecological environment by enhancing soil aggregate structure, increasing soil nutrient and beneficial microorganisms amount.
2016, 24(1): 98-104.
doi: 10.13930/j.cnki.cjea.150496
Abstract:
Soil phosphatase, especially acid phosphatase, plays a critical role in the decomposition of organic phosphorus and has a major impact on plant phosphorus uptake. Most Chinese researchers refer to the book entitled Soil Enzyme and Its Research Method, edited by Songyin Guan, for measurement method of soil acid phosphatase activity based on phenyl phosphate disodium salt substrate. In contrast, researchers outside China mainly cite the book entitled Methods of Soil Enzymology, edited by Dick, that was based on disodium p-Nitrophenyl phosphate tetrahydrate (PNPP) substrate. However, non-conspicuous coloration has existed for the measurement of products based on phenyl phosphate disodium salt substrate. Furthermore, it has been difficult for researchers to select an optimal method for determining acid phosphatase activity since these methods use different substrates. To determine the optimal method for measuring soil acid phosphatase activity, three different methods were used to measure the acid phosphatase activity of 10 soil samples of acid, neutral and alkaline soils, respectively. The three selected methods were 1) based on phenyl phosphate disodium salt substrate and colored using pH 5.0 acetate buffer (DPP 1); 2) based on phenyl phosphate disodium salt substrate and colored using pH 9.4 borate buffer (DPP 2) during chromogenic process; or 3) the PNPP method. Furthermore, the study analyzed the effects of different pH buffers and phenol concentrations on product absorbance. The results showed that chromogenic reaction of phenol with 2,6-dibromchinone-chlorimide was colorless within pH° ≤° 6 buffer solution with phenyl phosphate disodium salt as the substrate. In contrast, the above chromogenic reaction was observed under alkaline buffer (pH°≥°8) in all the samples. And there were significant differences in the Pearson correlation coefficient (R2) between phenol concentration and product absorbance at 0.01 level. Therefore, pH was a significant factor in determining the coloration between phenol and 2,6-dibromchinone-chlorimide. Furthermore, when acid phosphatase activity was determined using the PNPP method, the coefficient of variation of acid phosphatase activities in the 10 soil samples increased by 70.04%, 42.44% and 21.17% in acid, neutral and alkaline soils, respectively, which was in sharp contrast to those determined using the DPP 2 method. The range of soil acid phosphatase activities determined by the PNPP method was 27.18, 26.85 and 39.43 times larger than those determined by the DPP 2 method in acid, neutral and alkaline soils, respectively. These results suggested that regardless of soil acidity, PNPP was an easier and more sensitive method than DPP 2 for the estimation of soil acid phosphatase activity. In addition, if phenyl phosphate disodium salt was used as substrate in an assay, alkaline borate was the most suitable buffer for coloration reaction systems.
Soil phosphatase, especially acid phosphatase, plays a critical role in the decomposition of organic phosphorus and has a major impact on plant phosphorus uptake. Most Chinese researchers refer to the book entitled Soil Enzyme and Its Research Method, edited by Songyin Guan, for measurement method of soil acid phosphatase activity based on phenyl phosphate disodium salt substrate. In contrast, researchers outside China mainly cite the book entitled Methods of Soil Enzymology, edited by Dick, that was based on disodium p-Nitrophenyl phosphate tetrahydrate (PNPP) substrate. However, non-conspicuous coloration has existed for the measurement of products based on phenyl phosphate disodium salt substrate. Furthermore, it has been difficult for researchers to select an optimal method for determining acid phosphatase activity since these methods use different substrates. To determine the optimal method for measuring soil acid phosphatase activity, three different methods were used to measure the acid phosphatase activity of 10 soil samples of acid, neutral and alkaline soils, respectively. The three selected methods were 1) based on phenyl phosphate disodium salt substrate and colored using pH 5.0 acetate buffer (DPP 1); 2) based on phenyl phosphate disodium salt substrate and colored using pH 9.4 borate buffer (DPP 2) during chromogenic process; or 3) the PNPP method. Furthermore, the study analyzed the effects of different pH buffers and phenol concentrations on product absorbance. The results showed that chromogenic reaction of phenol with 2,6-dibromchinone-chlorimide was colorless within pH° ≤° 6 buffer solution with phenyl phosphate disodium salt as the substrate. In contrast, the above chromogenic reaction was observed under alkaline buffer (pH°≥°8) in all the samples. And there were significant differences in the Pearson correlation coefficient (R2) between phenol concentration and product absorbance at 0.01 level. Therefore, pH was a significant factor in determining the coloration between phenol and 2,6-dibromchinone-chlorimide. Furthermore, when acid phosphatase activity was determined using the PNPP method, the coefficient of variation of acid phosphatase activities in the 10 soil samples increased by 70.04%, 42.44% and 21.17% in acid, neutral and alkaline soils, respectively, which was in sharp contrast to those determined using the DPP 2 method. The range of soil acid phosphatase activities determined by the PNPP method was 27.18, 26.85 and 39.43 times larger than those determined by the DPP 2 method in acid, neutral and alkaline soils, respectively. These results suggested that regardless of soil acidity, PNPP was an easier and more sensitive method than DPP 2 for the estimation of soil acid phosphatase activity. In addition, if phenyl phosphate disodium salt was used as substrate in an assay, alkaline borate was the most suitable buffer for coloration reaction systems.
2016, 24(1): 105-111.
doi: 10.13930/j.cnki.cjea.150892
Abstract:
In recent years, Tetranychus truncatus Ehara has become one of the main pests in Hexi area of Gansu Province, for which pyridaben was widely used due to its special physiological mechanism and broad-spectrum efficiency. However, T. truncatus has developed resistance to the sole application of pyridaben for a long perod of time. The aim of this paper was to verify the effect of temperature on risk development rate of resistant and susceptible populations of Tetranychus truncatus Ehara. Then based on the results of resistance selection, the study evaluated the resistance risk of T. truncatus to pyridaben. To do this, the relationship between development rate and temperature was analyzed using the Wang-Lan-Ding model at six temperatures (16 ℃, 20 ℃, 24 ℃, 28 ℃, 32 ℃ and 36 ℃). The realized heritability (h2) of T. truncatus was estimated and the resistance risk of T. truncates to pyridaben under different resistance selection pressure predicted on the basis of resistance breeding and selection in the laboratory. Then threshold trait analysis was done in quantitative genetics to provide a theoretical support for the application of pyridaben and comprehensive control of T. truncatus. The results showed that based on the fitted Wang-Lan-Ding models, the minimum and maximum boundary temperatures of susceptible populations were 10.05 ℃ and 39.24 ℃, whereas that of the resistant populations were 13.45 ℃ and 41.89 ℃, respectively. The fitted models also showed that the maximum boundary temperature of resistant populations was significantly greater than that of susceptible populations. This implied that resistant populations had much stronger suitability to extreme temperatures than susceptible populations. The realized heritability (h2) of T. truncatus resistance to pyridaben was 0.11, and h2 for the first period and mid-term selection experiment (0.12 and 0.18, respectively) was higher than that for the later period (0.08), but h2 (0.14) sharply increased at terminal stage. Under laboratory conditions with h2 = 0.11, developing a 10-fold increase of resistance to pyridaben required 1023 generations under selection pressure (mortality) of 50%90%. Under field conditions (h2 = 0.05), it required 2146 generations to develop the same resistance level．The results suggested that T. truncatus had resistance risk to pyridaben. However, when pyridaben was applied under rotation with other insecticides without cross-resistance and reduced selection pressure, the resistance development rate of T. truncatus delayed.
In recent years, Tetranychus truncatus Ehara has become one of the main pests in Hexi area of Gansu Province, for which pyridaben was widely used due to its special physiological mechanism and broad-spectrum efficiency. However, T. truncatus has developed resistance to the sole application of pyridaben for a long perod of time. The aim of this paper was to verify the effect of temperature on risk development rate of resistant and susceptible populations of Tetranychus truncatus Ehara. Then based on the results of resistance selection, the study evaluated the resistance risk of T. truncatus to pyridaben. To do this, the relationship between development rate and temperature was analyzed using the Wang-Lan-Ding model at six temperatures (16 ℃, 20 ℃, 24 ℃, 28 ℃, 32 ℃ and 36 ℃). The realized heritability (h2) of T. truncatus was estimated and the resistance risk of T. truncates to pyridaben under different resistance selection pressure predicted on the basis of resistance breeding and selection in the laboratory. Then threshold trait analysis was done in quantitative genetics to provide a theoretical support for the application of pyridaben and comprehensive control of T. truncatus. The results showed that based on the fitted Wang-Lan-Ding models, the minimum and maximum boundary temperatures of susceptible populations were 10.05 ℃ and 39.24 ℃, whereas that of the resistant populations were 13.45 ℃ and 41.89 ℃, respectively. The fitted models also showed that the maximum boundary temperature of resistant populations was significantly greater than that of susceptible populations. This implied that resistant populations had much stronger suitability to extreme temperatures than susceptible populations. The realized heritability (h2) of T. truncatus resistance to pyridaben was 0.11, and h2 for the first period and mid-term selection experiment (0.12 and 0.18, respectively) was higher than that for the later period (0.08), but h2 (0.14) sharply increased at terminal stage. Under laboratory conditions with h2 = 0.11, developing a 10-fold increase of resistance to pyridaben required 1023 generations under selection pressure (mortality) of 50%90%. Under field conditions (h2 = 0.05), it required 2146 generations to develop the same resistance level．The results suggested that T. truncatus had resistance risk to pyridaben. However, when pyridaben was applied under rotation with other insecticides without cross-resistance and reduced selection pressure, the resistance development rate of T. truncatus delayed.
2016, 24(1): 112-120.
doi: 10.13930/j.cnki.cjea.150100
Abstract:
The study aimed to build sustainable application of evaluation index systems and methods and to select sustainable rotation patterns of multi-cropping with high efficiency green in the Poyang Lake Eco-Economic Zone. We conducted two consecutive years of field experiment and used a comprehensive index method to evaluate ecological and economic benefits of different rotation patterns of multi-cropping system in paddy fields. Based on the price of late rice, the results showed that crop yield of vegetables-sugar cane||soybean was the highest, followed by that of milk vetch-early rice-late rice and that of faba bean-early rice-sweet potato||maize the lowest. In 2012, the order of the overall efficiency index was vegetables-sugar cane||soybean > rapeseed-maize||soybean-late rice > faba bean-early rice-sweet potato||maize > milk vetch-early rice-late rice > winter fallow-early rice-late rice. This suggested that ‘vegetable-sugar cane||soybean’ intercropping pattern made rice production more economical as paddy fields supported high-yields with high efficiency. It was conducive for sustainable development of agricultural production. After multi-crop rotation, the order of the overall efficiency index for 2013 was milk vetch-early rice-late rice > vegetables-sugar cane||soybean > rapeseed-maize||soybean-late rice > faba bean-early rice-sweet potato||maize > winter fallow-early rice-late rice. The ‘milk vetch-early rice-late rice’ cropping pattern well accounted for the three main benefits conducive for sustainable agricultural production. Based on comprehensive benefits of the two-year experimental results, ‘vegetables-sugar cane||soybean → milk vetch-rice-rice’ cropping pattern had the highest efficiency and yield. It well accounted for social, ecological and economic benefits, favorable for food security and structural agricultural adjustment that in turn increased farmers’ income and other socio-economic benefits. It was also critical for the promotion of agricultural development in winter, making full use of natural resources that resulted in sustainable agricultural production. In a conclusion, ‘vegetables-sugar cane||soybean → milk vetch-early rice-late rice’ was the best rotation pattern for winter agriculture and multi-crop rotation system in terms of the scale of application in paddy fields in Poyang Lake Eco-Economic Zone.
The study aimed to build sustainable application of evaluation index systems and methods and to select sustainable rotation patterns of multi-cropping with high efficiency green in the Poyang Lake Eco-Economic Zone. We conducted two consecutive years of field experiment and used a comprehensive index method to evaluate ecological and economic benefits of different rotation patterns of multi-cropping system in paddy fields. Based on the price of late rice, the results showed that crop yield of vegetables-sugar cane||soybean was the highest, followed by that of milk vetch-early rice-late rice and that of faba bean-early rice-sweet potato||maize the lowest. In 2012, the order of the overall efficiency index was vegetables-sugar cane||soybean > rapeseed-maize||soybean-late rice > faba bean-early rice-sweet potato||maize > milk vetch-early rice-late rice > winter fallow-early rice-late rice. This suggested that ‘vegetable-sugar cane||soybean’ intercropping pattern made rice production more economical as paddy fields supported high-yields with high efficiency. It was conducive for sustainable development of agricultural production. After multi-crop rotation, the order of the overall efficiency index for 2013 was milk vetch-early rice-late rice > vegetables-sugar cane||soybean > rapeseed-maize||soybean-late rice > faba bean-early rice-sweet potato||maize > winter fallow-early rice-late rice. The ‘milk vetch-early rice-late rice’ cropping pattern well accounted for the three main benefits conducive for sustainable agricultural production. Based on comprehensive benefits of the two-year experimental results, ‘vegetables-sugar cane||soybean → milk vetch-rice-rice’ cropping pattern had the highest efficiency and yield. It well accounted for social, ecological and economic benefits, favorable for food security and structural agricultural adjustment that in turn increased farmers’ income and other socio-economic benefits. It was also critical for the promotion of agricultural development in winter, making full use of natural resources that resulted in sustainable agricultural production. In a conclusion, ‘vegetables-sugar cane||soybean → milk vetch-early rice-late rice’ was the best rotation pattern for winter agriculture and multi-crop rotation system in terms of the scale of application in paddy fields in Poyang Lake Eco-Economic Zone.
2016, 24(1): 121-130.
doi: 10.13930/j.cnki.cjea.150849
Abstract:
In recent years, the construction of eco-civilization in China has unprecedentedly attracted the attention of stakeholder authorities. One of the important issues of the construction of eco-civilization is the evaluation of regional resource environment pressure. Because of the variety and complexity of resources and environmental problems, it is not so easy to evaluate resource environment pressure. The Footprint Family method takes into account factors such as land and water resource carrying capacity, carbon emissions, forestry carbon sequestration and sustainable development. It therefore covers the basic connotation of eco-civilization construction. However, less domestic research has been reported on resource environment pressure in relation to Footprint Family. In this study, an evaluation system was constructed for resource environment pressure evaluation based on Footprint Family. The system was tested in the evaluation of resource environment pressure in Sichuan Province, where lies in the Silk Road Economic Belt, in order to promote the construction of eco-civilization and development of eco-civilization legislation and systematical construction. The results showed that per capita ecological footprint increased by 109.57% whereas per capita biocapacity had no obvious change from 1990 to 2013. Therefore, ecological pressure index increased from below-average (Ⅲa) to very high level (Ⅲb) in the period. In the same period, forestry carbon sequestration increased by 32.01%, greenhouse gases (GHGs) emissions remained at low grade (Ⅰb), while GHG emission index sharply increased by 234.97%. As the growth of water footprint was very small, water resource pressure was very small too (Ⅰa). However, decrease in available water resource was not negligible. Pressure on provincial resources and environment increased from very low (Ⅰa) to below-average (Ⅱa) grade. Spatially, ecological pressure was at very low grade (Ⅰa) in Ganzi and Aba, at above-average grade (Ⅱb) in Guangyuan, and at very high grade (Ⅲb) in other regions. GHG emission index was very high (Ⅲb) in Panzhihua, high (Ⅲa) in Neijiang, above-average (Ⅱb) in Leshan, below-average (Ⅱa) in Meishan, with carbon sequestration at Ⅰa (very low) grade in Ganzi, Ya’an and Aba, and?Ⅰb (very low) grade in other regions. Water resource pressure was at very high grade (Ⅲb) in Zigong, Suining, Meishan, Neijiang and Ziyang. It was at high grade (Ⅲa) in Chengdu, above-average (Ⅱb) in Luzhou and Dazhou, below-average grade (Ⅱa) in Deyang, low grade (Ⅰb) in Yibin and Panzhihua , and was at very low grade (Ⅰa) in other regions. Resource environment pressure was at very low grade (Ⅰa) in Aba, Ganzi, Ya’an and Guangyuan, low grade (Ⅰb) in Liangshan City and Mianyang, below-average (Ⅱa) in Guang’an, Bazhong and Nanchong, above-average (Ⅲb) in Yibin, Deyang, Leshan and Dazhou, high grade (Ⅲa) in Luzhou, Ziyang and Chengdu, and very high grade (Ⅲb) in Suining, Panzhihua, Meishan, Zigong and Neijiang. Therefore resource environment pressure was due mainly to high ecological pressure driven by the large population with relatively little cultivated land per capita in Sichuan Province. The construction of future eco-civilization should strictly be adapted to cultivated land policies that were in turn based on ecological red-lines to ensure productive cultivation. In addition, the optimization of energy consumption structure by vigorously developing hydropower and strengthening forest conservation to improve forest carbon sink capability was an indispensable option in Sichuan Province.
In recent years, the construction of eco-civilization in China has unprecedentedly attracted the attention of stakeholder authorities. One of the important issues of the construction of eco-civilization is the evaluation of regional resource environment pressure. Because of the variety and complexity of resources and environmental problems, it is not so easy to evaluate resource environment pressure. The Footprint Family method takes into account factors such as land and water resource carrying capacity, carbon emissions, forestry carbon sequestration and sustainable development. It therefore covers the basic connotation of eco-civilization construction. However, less domestic research has been reported on resource environment pressure in relation to Footprint Family. In this study, an evaluation system was constructed for resource environment pressure evaluation based on Footprint Family. The system was tested in the evaluation of resource environment pressure in Sichuan Province, where lies in the Silk Road Economic Belt, in order to promote the construction of eco-civilization and development of eco-civilization legislation and systematical construction. The results showed that per capita ecological footprint increased by 109.57% whereas per capita biocapacity had no obvious change from 1990 to 2013. Therefore, ecological pressure index increased from below-average (Ⅲa) to very high level (Ⅲb) in the period. In the same period, forestry carbon sequestration increased by 32.01%, greenhouse gases (GHGs) emissions remained at low grade (Ⅰb), while GHG emission index sharply increased by 234.97%. As the growth of water footprint was very small, water resource pressure was very small too (Ⅰa). However, decrease in available water resource was not negligible. Pressure on provincial resources and environment increased from very low (Ⅰa) to below-average (Ⅱa) grade. Spatially, ecological pressure was at very low grade (Ⅰa) in Ganzi and Aba, at above-average grade (Ⅱb) in Guangyuan, and at very high grade (Ⅲb) in other regions. GHG emission index was very high (Ⅲb) in Panzhihua, high (Ⅲa) in Neijiang, above-average (Ⅱb) in Leshan, below-average (Ⅱa) in Meishan, with carbon sequestration at Ⅰa (very low) grade in Ganzi, Ya’an and Aba, and?Ⅰb (very low) grade in other regions. Water resource pressure was at very high grade (Ⅲb) in Zigong, Suining, Meishan, Neijiang and Ziyang. It was at high grade (Ⅲa) in Chengdu, above-average (Ⅱb) in Luzhou and Dazhou, below-average grade (Ⅱa) in Deyang, low grade (Ⅰb) in Yibin and Panzhihua , and was at very low grade (Ⅰa) in other regions. Resource environment pressure was at very low grade (Ⅰa) in Aba, Ganzi, Ya’an and Guangyuan, low grade (Ⅰb) in Liangshan City and Mianyang, below-average (Ⅱa) in Guang’an, Bazhong and Nanchong, above-average (Ⅲb) in Yibin, Deyang, Leshan and Dazhou, high grade (Ⅲa) in Luzhou, Ziyang and Chengdu, and very high grade (Ⅲb) in Suining, Panzhihua, Meishan, Zigong and Neijiang. Therefore resource environment pressure was due mainly to high ecological pressure driven by the large population with relatively little cultivated land per capita in Sichuan Province. The construction of future eco-civilization should strictly be adapted to cultivated land policies that were in turn based on ecological red-lines to ensure productive cultivation. In addition, the optimization of energy consumption structure by vigorously developing hydropower and strengthening forest conservation to improve forest carbon sink capability was an indispensable option in Sichuan Province.
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：Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
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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