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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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2015 Vol. 23, No. 9
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2015, 23(9): 1073-1082.
doi: 10.13930/j.cnki.cjea.150237
Abstract:
Incorporation of crop straw into the soil is an major soil management practice that improves soil fertility for sustainable agriculture. However, its application is severely hindered by low economic efficiency, low yield and negative environmental effects. This paper reviewed the effects of returning 100% of crop straw into the soil on crop yield, the mechanism and characteristics of straw decomposition, and environmental effects and regulation of straw return. For this purpose, the paper reviewed a huge number of published scientific research papers on the progresses of the effects of crop straw return into the soil. The results showed that 100% straw return improved soil fertility and increased yield of wheat and rice, which increased with increasing time of straw return. The decomposition rates of wheat and rape straws were 50%?66% during rice growing season, respectively releasing 42%?58%, 55%?68% and 92%?98% of total straw nitrogen (N), phosphorous (P) and potassium (K) into the soil. Straw return significantly increased soil organic carbon storage and reduced runoff loss. However, it enhanced CH4 emission, ammonia volatilization and nutrient loss through leaching. In order to mitigate the negative effects of straw return on economic growth and the environment, it was necessary to increase the proportion of N fertilization at the early stage of rice and wheat growth, properly reduce the N fertilization dose during whole growing season, and reduce P fertilization and especially K fertilization rates. In order to reduce CH4 emission, it was recommended to apply straw return during dry periods and use intermittent flood/moist irrigation during rice growing season.
Incorporation of crop straw into the soil is an major soil management practice that improves soil fertility for sustainable agriculture. However, its application is severely hindered by low economic efficiency, low yield and negative environmental effects. This paper reviewed the effects of returning 100% of crop straw into the soil on crop yield, the mechanism and characteristics of straw decomposition, and environmental effects and regulation of straw return. For this purpose, the paper reviewed a huge number of published scientific research papers on the progresses of the effects of crop straw return into the soil. The results showed that 100% straw return improved soil fertility and increased yield of wheat and rice, which increased with increasing time of straw return. The decomposition rates of wheat and rape straws were 50%?66% during rice growing season, respectively releasing 42%?58%, 55%?68% and 92%?98% of total straw nitrogen (N), phosphorous (P) and potassium (K) into the soil. Straw return significantly increased soil organic carbon storage and reduced runoff loss. However, it enhanced CH4 emission, ammonia volatilization and nutrient loss through leaching. In order to mitigate the negative effects of straw return on economic growth and the environment, it was necessary to increase the proportion of N fertilization at the early stage of rice and wheat growth, properly reduce the N fertilization dose during whole growing season, and reduce P fertilization and especially K fertilization rates. In order to reduce CH4 emission, it was recommended to apply straw return during dry periods and use intermittent flood/moist irrigation during rice growing season.
2015, 23(9): 1083-1092.
doi: 10.13930/j.cnki.cjea.150392
Abstract:
Phalaris minor Retz., a native weed of the Mediterranean region, is the most serious annual grass weed in winter wheat fields. This paper reviewed the current state of researches on the invasive species, P. minor. Globally, P. minor has been reported in over 60 countries, covering all the continents except the polar regions. Presently, P. minor has spread widely across Yunnan Province and can now be found in Kunming, Chuxiong, Yuxi, Dali, Baoshan, Dehong, Yuxi and Honghe Cities. It is considered a seriously threat to the local economy and food production. The international drive is to adopt more effective and scientific forecast and control for P. minor infestation. In recent years, an increasing number of foreign researchers have become interested in studying this weed species and thus much progress has been made in understanding the biology and ecology of this species of weeds. However, research on P. minor in China has remained largely inadequate, resulting in difficulties in developing reliable early warning and control system for the weed. This paper reviewed some of the hot research issues on P. minor based on the abroad and domestic research results, including its distribution all across the world, the possible reasons for the damage it caused to crops (e. g. interspecific competition, allelopathy), the mechanisms underlying its invasion and spread, genetic variations in the weed population, and the highly adaptive ability and biological characteristics of the invasive weed to explain its highly successful rate of spread (e. g., morphological similarity of P. minor with wheat, small seed size and persistent soil seed bank). The paper also reviewed control methods of P. minor, which were divided into three general categories — manual, chemical and biological. Finally, three areas of future research were proposed: 1) multi-disciplinary mechanisms underlying its invasion and spread; 2) eco-physiological adaptation of the invasive species to global climate change; and 3) effective control of the invasive species. Thus it was very important to build an in-depth research on the invasive species in order to predict and prevent the successful invasion of P. minor, and to eventually lay the theoretical and technical support for the management of P. minor.
Phalaris minor Retz., a native weed of the Mediterranean region, is the most serious annual grass weed in winter wheat fields. This paper reviewed the current state of researches on the invasive species, P. minor. Globally, P. minor has been reported in over 60 countries, covering all the continents except the polar regions. Presently, P. minor has spread widely across Yunnan Province and can now be found in Kunming, Chuxiong, Yuxi, Dali, Baoshan, Dehong, Yuxi and Honghe Cities. It is considered a seriously threat to the local economy and food production. The international drive is to adopt more effective and scientific forecast and control for P. minor infestation. In recent years, an increasing number of foreign researchers have become interested in studying this weed species and thus much progress has been made in understanding the biology and ecology of this species of weeds. However, research on P. minor in China has remained largely inadequate, resulting in difficulties in developing reliable early warning and control system for the weed. This paper reviewed some of the hot research issues on P. minor based on the abroad and domestic research results, including its distribution all across the world, the possible reasons for the damage it caused to crops (e. g. interspecific competition, allelopathy), the mechanisms underlying its invasion and spread, genetic variations in the weed population, and the highly adaptive ability and biological characteristics of the invasive weed to explain its highly successful rate of spread (e. g., morphological similarity of P. minor with wheat, small seed size and persistent soil seed bank). The paper also reviewed control methods of P. minor, which were divided into three general categories — manual, chemical and biological. Finally, three areas of future research were proposed: 1) multi-disciplinary mechanisms underlying its invasion and spread; 2) eco-physiological adaptation of the invasive species to global climate change; and 3) effective control of the invasive species. Thus it was very important to build an in-depth research on the invasive species in order to predict and prevent the successful invasion of P. minor, and to eventually lay the theoretical and technical support for the management of P. minor.
2015, 23(9): 1093-1101.
doi: 10.13930/j.cnki.cjea.150155
Abstract:
In order to investigate the effects of chemical regulation and phosphorus (P) fertilization on P in maize/peanut intercropping system, a field experiment was conducted in 2012 and 2013 in the farm of Henan University of Science and Technology. P content, accumulation and distribution in different organs of intercropped maize and peanut were determined and the effects of chemical regulation and P fertilization on intercropped maize/peanut analyzed. The experiment included eight treatments — monocultured maize, monocultured peanut, intercropped maize/peanut with chemical regulation, and intercropped maize/peanut without chemical regulation of 4 planting models with and without P fertilizer application [P fertilizer dose was 180 kg(P2O5)·hm–2]. Results showed that compared with monocropping system of maize, maize/peanut intercropping system increased seed P content and accumulated P in stem and seed of maize. Also while intercropping enhanced P distribution in maize seed, it obviously limited P content and accumulation in different organs of peanut and P distribution to nuts. Compared with monoculture systems, intercropping improved P uptake with obvious P intercropping advantages of 15.9919.54 kg(P)·hm–2. During the little bell mouth stage, spraying chemical regulator to intercropped maize increased P content in maize seed, decreased P accumulation in maize stem, leaf and seed, and then promoted P distribution in maize seed. However, spraying chemical regulator to intercropped maize obviously increased P content in seed, P accumulation in stem, leaf and nut, and then promoted P distribution in nut of peanut intercropped with maize. Compared with spraying chemical agent to intercropped maize without P fertilization, spraying chemical agent to intercropped maize with P fertilization significantly enhanced P content and accumulation in different organs of maize and peanut, increased P distribution in maize seed and peanut nut. Also compared with none-P intercropping, intercropping with P fertilization improved P absorption of the system, and increased P intercropping advantage to 19.5022.00 kg(P)·hm–2, representing an increase of 16.51%57.51%. This suggested that the application of P fertilizer had a significant advantage in term of P availability under maize/peanut intercropping system. Chemical regulation with P fertilization enhanced P uptake, thereby bringing significant advantage of maize/peanut intercropping system.
In order to investigate the effects of chemical regulation and phosphorus (P) fertilization on P in maize/peanut intercropping system, a field experiment was conducted in 2012 and 2013 in the farm of Henan University of Science and Technology. P content, accumulation and distribution in different organs of intercropped maize and peanut were determined and the effects of chemical regulation and P fertilization on intercropped maize/peanut analyzed. The experiment included eight treatments — monocultured maize, monocultured peanut, intercropped maize/peanut with chemical regulation, and intercropped maize/peanut without chemical regulation of 4 planting models with and without P fertilizer application [P fertilizer dose was 180 kg(P2O5)·hm–2]. Results showed that compared with monocropping system of maize, maize/peanut intercropping system increased seed P content and accumulated P in stem and seed of maize. Also while intercropping enhanced P distribution in maize seed, it obviously limited P content and accumulation in different organs of peanut and P distribution to nuts. Compared with monoculture systems, intercropping improved P uptake with obvious P intercropping advantages of 15.9919.54 kg(P)·hm–2. During the little bell mouth stage, spraying chemical regulator to intercropped maize increased P content in maize seed, decreased P accumulation in maize stem, leaf and seed, and then promoted P distribution in maize seed. However, spraying chemical regulator to intercropped maize obviously increased P content in seed, P accumulation in stem, leaf and nut, and then promoted P distribution in nut of peanut intercropped with maize. Compared with spraying chemical agent to intercropped maize without P fertilization, spraying chemical agent to intercropped maize with P fertilization significantly enhanced P content and accumulation in different organs of maize and peanut, increased P distribution in maize seed and peanut nut. Also compared with none-P intercropping, intercropping with P fertilization improved P absorption of the system, and increased P intercropping advantage to 19.5022.00 kg(P)·hm–2, representing an increase of 16.51%57.51%. This suggested that the application of P fertilizer had a significant advantage in term of P availability under maize/peanut intercropping system. Chemical regulation with P fertilization enhanced P uptake, thereby bringing significant advantage of maize/peanut intercropping system.
2015, 23(9): 1102-1111.
doi: 10.13930/j.cnki.cjea.150175
Abstract:
To study the effects of different rotational tillage patterns on soil physical properties and crop yield under winter wheat- spring maize single-cropping rotation systems in Weibei highlands, a 7-year on-site conservation tillage experiment was conducted, which consisted of three rotational tillage and three continuous tillage treatments. The rotational tillage systems included NT/ST (yearly rotation between no-tillage and subsoiling), ST/CT (yearly rotation between subsoiling and conventional tillage) and CT/NT (yearly rotation between conventional tillage and no-tillage). Also the continuous tillage treatments included continuous no-tillage (NT/NT), continuous subsoiling (ST/ST) and continuous conventional tillage (CT/CT). The study was conducted in wheat-maize rotation fields in 2007 to 2014 in Heyang County, Shaanxi Province. Soil physical properties (e.g., bulk density, soil aggregates and soil moisture) and crop yield under different tillage treatments were measured in 2014. The results were as follows: 1) Soil bulk density, soil porosity and field water capacity were significantly impacted by the three rotational tillage patterns, and were best under NT/ST rotational tillage. Compared with CT/CT treatment, NT/ST rotational tillage treatment increased average field capacity in the 060 cm soil layer by 12.9%. 2) The properties of soil aggregates changed significantly under different rotational tillage treatments. The NT/ST treatment was the best with the highest macro-aggregate content (R0.25), lowest rate of structure break-up, lowest unstable aggregate index (ELT), highest water-stable aggregate mean weight diameter (MWD) and lowest fractal dimension (D) of mechanical-stable and water-stable aggregates. 3) In wheat growing period, average soil water storage in the 0200 cm soil layer and yield of wheat under NT/ST treatment were respectively 17.7 mm and 9.5% higher than CT/CT treatment. It was concluded that rotational tillage was conducive for improving soil physical structure. Also NT/ST rotational tillage was more favorable for large topsoil aggregates and soil structure stability, for improving soil water conservation and then for increasing crop yield. Thus NT/ST treatment was a more appropriate rotational tillage pattern for wheat-maize rotation fields in Weibei highlands.
To study the effects of different rotational tillage patterns on soil physical properties and crop yield under winter wheat- spring maize single-cropping rotation systems in Weibei highlands, a 7-year on-site conservation tillage experiment was conducted, which consisted of three rotational tillage and three continuous tillage treatments. The rotational tillage systems included NT/ST (yearly rotation between no-tillage and subsoiling), ST/CT (yearly rotation between subsoiling and conventional tillage) and CT/NT (yearly rotation between conventional tillage and no-tillage). Also the continuous tillage treatments included continuous no-tillage (NT/NT), continuous subsoiling (ST/ST) and continuous conventional tillage (CT/CT). The study was conducted in wheat-maize rotation fields in 2007 to 2014 in Heyang County, Shaanxi Province. Soil physical properties (e.g., bulk density, soil aggregates and soil moisture) and crop yield under different tillage treatments were measured in 2014. The results were as follows: 1) Soil bulk density, soil porosity and field water capacity were significantly impacted by the three rotational tillage patterns, and were best under NT/ST rotational tillage. Compared with CT/CT treatment, NT/ST rotational tillage treatment increased average field capacity in the 060 cm soil layer by 12.9%. 2) The properties of soil aggregates changed significantly under different rotational tillage treatments. The NT/ST treatment was the best with the highest macro-aggregate content (R0.25), lowest rate of structure break-up, lowest unstable aggregate index (ELT), highest water-stable aggregate mean weight diameter (MWD) and lowest fractal dimension (D) of mechanical-stable and water-stable aggregates. 3) In wheat growing period, average soil water storage in the 0200 cm soil layer and yield of wheat under NT/ST treatment were respectively 17.7 mm and 9.5% higher than CT/CT treatment. It was concluded that rotational tillage was conducive for improving soil physical structure. Also NT/ST rotational tillage was more favorable for large topsoil aggregates and soil structure stability, for improving soil water conservation and then for increasing crop yield. Thus NT/ST treatment was a more appropriate rotational tillage pattern for wheat-maize rotation fields in Weibei highlands.
2015, 23(9): 1112-1121.
doi: 10.13930/j.cnki.cjea.150040
Abstract:
In order to verify the effect of moistube-irrigation under plastic film mulching on water and salt transport in tomato in slight alkaline soils under greenhouse conditions, three buried depths (10 cm, 15 cm, 20 cm) of moistubes of moistube- irrigation under plastic film mulching were designed and the effects of the moistube depths on water content and salinity of soils under (in tomato planting row) and between (between tomato rows) plastic films investigated. The results showed that the change trends in soil water content and salinity were consistent for different moistube depths under and between the plastic films. Under plastic film, soil water content increased initially and then decreased, whereas salinity decreased with time. Between plastic films, soil water content and salinity increased over time. The soil water content between plastic films was less than that under plastic film. With increasing soil depth, the difference in soil water content between under-film and between-films reduced. The difference of soil water content between under-film and between-films was maximal in surface soil. In 5060 cm soil layer, water contents under plastic film and between plastic films were tend to be consistent. The deeper the moistube was, the higher the soil water content was. At fruiting stage of tomato, soil water contents were 23.31%, 24.46% and 22.42% for moistube depths of 20 cm, 15 cm and 10 cm, respectively. The difference in soil water content between under-film and between-films for 10 cm depth of moistube was less those for 15 cm and 20 cm depths of moistubes. Soil salinity under plastic film was less than that between plastic films, and with the increase of buried depth of moistube, the difference between under-film and between-films increased. In 040 cm layer under plastic film, soil was desalinated during the whole growth period of tomato, though the relative desalination rate decreased with increasing soil depth. Also in 040 cm soil layer, the nearer to the moistube, the more obvious the effect of desalination. The soil layer of 4060 cm was in slight salification due to less soil water content and salinity. The 1020 cm soil layer had maximal soil water content, minimum salinity and highest salt desalination rate. However, between plastic films, the soil with depth of 060 cm was in salt deposition state, and the salt deposition rate decreased with the increase of soil depth. Salt deposition rate was highest for the 020 cm soil depth. At fruiting stage of tomato, average maximal desalination rates of 1020 soil layer under plastic film were 24.66%, 32.28% and 14.71% for moistube depths of 20 cm, 15 cm and 10 cm. At seedling and last fruiting stages of tomato, the desalination rates of 1020 soil layer were also highest for 15 cm moistube depth among three buried depths, which were 27.42% and 24.67%. The results showed a significant effect of tube depth of moistube-irrigation under plastic film mulching on salt-leaching of soil in tomato root area. In summary, the buried depth of 15 cm of moistube had the highest average desalination rate of 26.05% and the highest average soil water content of 25.1%, which created an appropriate soil water-salt environment for tomato growth. 15 cm was the best moistube depth of moistube-irrigation under plastic film mulching.
In order to verify the effect of moistube-irrigation under plastic film mulching on water and salt transport in tomato in slight alkaline soils under greenhouse conditions, three buried depths (10 cm, 15 cm, 20 cm) of moistubes of moistube- irrigation under plastic film mulching were designed and the effects of the moistube depths on water content and salinity of soils under (in tomato planting row) and between (between tomato rows) plastic films investigated. The results showed that the change trends in soil water content and salinity were consistent for different moistube depths under and between the plastic films. Under plastic film, soil water content increased initially and then decreased, whereas salinity decreased with time. Between plastic films, soil water content and salinity increased over time. The soil water content between plastic films was less than that under plastic film. With increasing soil depth, the difference in soil water content between under-film and between-films reduced. The difference of soil water content between under-film and between-films was maximal in surface soil. In 5060 cm soil layer, water contents under plastic film and between plastic films were tend to be consistent. The deeper the moistube was, the higher the soil water content was. At fruiting stage of tomato, soil water contents were 23.31%, 24.46% and 22.42% for moistube depths of 20 cm, 15 cm and 10 cm, respectively. The difference in soil water content between under-film and between-films for 10 cm depth of moistube was less those for 15 cm and 20 cm depths of moistubes. Soil salinity under plastic film was less than that between plastic films, and with the increase of buried depth of moistube, the difference between under-film and between-films increased. In 040 cm layer under plastic film, soil was desalinated during the whole growth period of tomato, though the relative desalination rate decreased with increasing soil depth. Also in 040 cm soil layer, the nearer to the moistube, the more obvious the effect of desalination. The soil layer of 4060 cm was in slight salification due to less soil water content and salinity. The 1020 cm soil layer had maximal soil water content, minimum salinity and highest salt desalination rate. However, between plastic films, the soil with depth of 060 cm was in salt deposition state, and the salt deposition rate decreased with the increase of soil depth. Salt deposition rate was highest for the 020 cm soil depth. At fruiting stage of tomato, average maximal desalination rates of 1020 soil layer under plastic film were 24.66%, 32.28% and 14.71% for moistube depths of 20 cm, 15 cm and 10 cm. At seedling and last fruiting stages of tomato, the desalination rates of 1020 soil layer were also highest for 15 cm moistube depth among three buried depths, which were 27.42% and 24.67%. The results showed a significant effect of tube depth of moistube-irrigation under plastic film mulching on salt-leaching of soil in tomato root area. In summary, the buried depth of 15 cm of moistube had the highest average desalination rate of 26.05% and the highest average soil water content of 25.1%, which created an appropriate soil water-salt environment for tomato growth. 15 cm was the best moistube depth of moistube-irrigation under plastic film mulching.
2015, 23(9): 1122-1130.
doi: 10.13930/j.cnki.cjea.141338
Abstract:
Shortage of water resources and soil salinization threaten oasis agriculture ecosystem health and stability, which are the two big problems in sustainable agricultural development in arid oasis irrigation areas. While there is need to adopt new irrigation technologies in these regions, such actions could break up the balance of soil water and salt. This could eventually cause secondary soil salinization of farmlands that will in turn decrease farmland productivity. To develop new water-saving irrigation technologies, prevent secondary soil salinization and ensure sustainable agricultural development in irrigated arid oasis areas of Northwest China, it is important to resolve existing conflicts between the adoption of water-saving irrigation technology and the control of secondary soil salinization. Thus an experiment was conducted in spring wheat fields from 2005 to 2010 to monitor soil salinity characteristics under conventional tillage (CT), fresh raised-bed (FRB), permanent raised-bed (PRB) and zero-tillage in flat fields (ZT, control). The results showed that soil salt content increased from sowing to harvest under FRB by 83.3% in the 020 cm, 77.2% in the 2040 cm, 47.6% in the 4060 cm and 84.0% in the 60100 cm soil layers. For the same layers under PRB treatment, soil salt content increased by 62.6%, 46.3%, 28.2% and 103.6%, respectively. Main salt accumulation zone under furrow irrigated FRB and PRB treatments was the 060 cm soil layer. However, main salt accumulation was the 100160 cm soil layer under flood irrigated ZT and CT treatments while there was alternative soil desalination and accumulation in the 0200 cm soil profile. Soil salt content in the 060 cm soil layer decreased with decreasing irrigation while it increased with decreasing irrigation in the 60200 cm soil layer. Soil salinity in root-layer soil depth (0200 cm) was significantly greater from first irrigation to harvest under PRB treatment than under FRB treatment. There was soil salt accumulation in the 6080 cm soil layer under FRB treatment and in the 4060 cm soil layer under PRB treatment. Soil salinity was significantly greater under ZT than CT treatments in the 0100 cm soil layer. Following normal irrigation, soil salinity became redistributed in the middle and surface of beds under FRB treatment. Soil salt migration from the edge to the center of the beds was most notable under PRB treatment. Ridge tillage and bed farming significantly increased salt accumulation in the soil profile. With increasing number of years of cropping and irrigation, salt increasingly migrated and accumulated in the middle of the beds. Thus a fraction of the irrigation water leached salts from ridges/beds and from the soil profile. There was need for at least one irrigation to be larger than normal (over the top of the beds) to enhance redistribution of salts below root-zone soil layer.
Shortage of water resources and soil salinization threaten oasis agriculture ecosystem health and stability, which are the two big problems in sustainable agricultural development in arid oasis irrigation areas. While there is need to adopt new irrigation technologies in these regions, such actions could break up the balance of soil water and salt. This could eventually cause secondary soil salinization of farmlands that will in turn decrease farmland productivity. To develop new water-saving irrigation technologies, prevent secondary soil salinization and ensure sustainable agricultural development in irrigated arid oasis areas of Northwest China, it is important to resolve existing conflicts between the adoption of water-saving irrigation technology and the control of secondary soil salinization. Thus an experiment was conducted in spring wheat fields from 2005 to 2010 to monitor soil salinity characteristics under conventional tillage (CT), fresh raised-bed (FRB), permanent raised-bed (PRB) and zero-tillage in flat fields (ZT, control). The results showed that soil salt content increased from sowing to harvest under FRB by 83.3% in the 020 cm, 77.2% in the 2040 cm, 47.6% in the 4060 cm and 84.0% in the 60100 cm soil layers. For the same layers under PRB treatment, soil salt content increased by 62.6%, 46.3%, 28.2% and 103.6%, respectively. Main salt accumulation zone under furrow irrigated FRB and PRB treatments was the 060 cm soil layer. However, main salt accumulation was the 100160 cm soil layer under flood irrigated ZT and CT treatments while there was alternative soil desalination and accumulation in the 0200 cm soil profile. Soil salt content in the 060 cm soil layer decreased with decreasing irrigation while it increased with decreasing irrigation in the 60200 cm soil layer. Soil salinity in root-layer soil depth (0200 cm) was significantly greater from first irrigation to harvest under PRB treatment than under FRB treatment. There was soil salt accumulation in the 6080 cm soil layer under FRB treatment and in the 4060 cm soil layer under PRB treatment. Soil salinity was significantly greater under ZT than CT treatments in the 0100 cm soil layer. Following normal irrigation, soil salinity became redistributed in the middle and surface of beds under FRB treatment. Soil salt migration from the edge to the center of the beds was most notable under PRB treatment. Ridge tillage and bed farming significantly increased salt accumulation in the soil profile. With increasing number of years of cropping and irrigation, salt increasingly migrated and accumulated in the middle of the beds. Thus a fraction of the irrigation water leached salts from ridges/beds and from the soil profile. There was need for at least one irrigation to be larger than normal (over the top of the beds) to enhance redistribution of salts below root-zone soil layer.
2015, 23(9): 1131-1141.
doi: 10.13930/j.cnki.cjea.150097
Abstract:
Environmental problems due to livestock and poultry waste releases have worsened with increasing scale of breeding industries. Utilization of livestock and poultry wastes in farmlands could limit the production and application of chemical fertilizers and the corresponding pollution. However, this could as well lead to greenhouse gases emissions in the agro-ecological systems. Studies on greenhouse gases emissions from farmland with partial replacements of chemical nitrogen (N) fertilizers by livestock and poultry manure are critical for exploring farmland environmental carrying capacity of livestock and poultry wastes. This study aimed to assess greenhouse gases emission per ton of produced rice with different fertilization practices. Life Cycle Assessment (LCA) was used to evaluate greenhouse gases emission of a rice production system under different substitution ratios of chemical N fertilizer with pig manure. The life cycle of one ton of produced rice was divided into three phases — raw material mining, agricultural materials production and crop planting. Inventory analysis and calculation were performed for the three stages. Pure chemical fertilizer (N1), half manure N plus half inorganic fertilizer N (NM1) and manure N (NM2) treatments were set up in field plots. Greenhouse gases (carbon dioxide, methane and nitrous oxide) from paddy fields were collected and measured by the static chamber-gas chromatography method, while CO2 emissions from other sources were calculated using the amount and emission factors of input materials as documented in relevant literatures. The results showed that gross greenhouse gases emissions under N1, MN1 and NM2 treatments were 1.760 t(CO2-eq)·t-1, 1.997 t(CO2-eq)·t-1 and 2.550 t(CO2-eq)·t-1, of which 0.145 t(CO2-eq)·t-1, 0.085 t(CO2-eq)·t-1 and 0.047 t(CO2-eq)·t-1 were for raw material mining, 0.032 t(CO2-eq)·t-1, 0.014 t(CO2-eq)·t-1 and 0 t(CO2-eq)·t-1 for agricultural materials production, and 1.583 t(CO2-eq)·t-1, 1.898 t(CO2-eq)·t-1and 2.503 t(CO2-eq)·t-1 for crop planting. Under NM1 and NM2 treatments, crop yields increased respectively by 15.87% and 9.14% and the total greenhouse gases emission during the whole life cycle increased by 13.63% and 44.89%. Compared with N1, greenhouse gases emissions under NM1 and NM2 treatments decreased respectively by 41.37% and 61.58% for raw material mining, 56.25% and 100.00% for agricultural materials production, but then increased by 20.25% and 58.23% for crop planting. Greenhouse gases emission under the three treatments that was due to resource consumption during field operations was 0.069t(CO2-eq)·t-1, 0.065t(CO2-eq)·t-1 and 0.075 t(CO2-eq)·t-1. The CO2 emissions were divided into direct and indirect emissions. Direct emissions came from the use of diesel oil, electricity, pesticides and field emissions during rice growth period at crop planting stage. Then indirect emissions were from the use of raw coal and crude oil (at raw material mining stage), and coal and electricity (at agricultural materials production stage). Irrigation was the main sources of greenhouse gases emission during field management, followed by tillage, cutting stubble and reaping. NM1 and NM2 treatments decreased greenhouse gases emission at raw material mining and agricultural materials production stages, but significantly increased greenhouse gases emissions at crop planting stage. This subsequently increased greenhouse gases emissions in rice production. Advanced fertilization technologies should be explored to improve N utilization efficiency so as to reduce environmental impact. Also livestock and poultry manures should be harmlessly processed before farmland utilization.
Environmental problems due to livestock and poultry waste releases have worsened with increasing scale of breeding industries. Utilization of livestock and poultry wastes in farmlands could limit the production and application of chemical fertilizers and the corresponding pollution. However, this could as well lead to greenhouse gases emissions in the agro-ecological systems. Studies on greenhouse gases emissions from farmland with partial replacements of chemical nitrogen (N) fertilizers by livestock and poultry manure are critical for exploring farmland environmental carrying capacity of livestock and poultry wastes. This study aimed to assess greenhouse gases emission per ton of produced rice with different fertilization practices. Life Cycle Assessment (LCA) was used to evaluate greenhouse gases emission of a rice production system under different substitution ratios of chemical N fertilizer with pig manure. The life cycle of one ton of produced rice was divided into three phases — raw material mining, agricultural materials production and crop planting. Inventory analysis and calculation were performed for the three stages. Pure chemical fertilizer (N1), half manure N plus half inorganic fertilizer N (NM1) and manure N (NM2) treatments were set up in field plots. Greenhouse gases (carbon dioxide, methane and nitrous oxide) from paddy fields were collected and measured by the static chamber-gas chromatography method, while CO2 emissions from other sources were calculated using the amount and emission factors of input materials as documented in relevant literatures. The results showed that gross greenhouse gases emissions under N1, MN1 and NM2 treatments were 1.760 t(CO2-eq)·t-1, 1.997 t(CO2-eq)·t-1 and 2.550 t(CO2-eq)·t-1, of which 0.145 t(CO2-eq)·t-1, 0.085 t(CO2-eq)·t-1 and 0.047 t(CO2-eq)·t-1 were for raw material mining, 0.032 t(CO2-eq)·t-1, 0.014 t(CO2-eq)·t-1 and 0 t(CO2-eq)·t-1 for agricultural materials production, and 1.583 t(CO2-eq)·t-1, 1.898 t(CO2-eq)·t-1and 2.503 t(CO2-eq)·t-1 for crop planting. Under NM1 and NM2 treatments, crop yields increased respectively by 15.87% and 9.14% and the total greenhouse gases emission during the whole life cycle increased by 13.63% and 44.89%. Compared with N1, greenhouse gases emissions under NM1 and NM2 treatments decreased respectively by 41.37% and 61.58% for raw material mining, 56.25% and 100.00% for agricultural materials production, but then increased by 20.25% and 58.23% for crop planting. Greenhouse gases emission under the three treatments that was due to resource consumption during field operations was 0.069t(CO2-eq)·t-1, 0.065t(CO2-eq)·t-1 and 0.075 t(CO2-eq)·t-1. The CO2 emissions were divided into direct and indirect emissions. Direct emissions came from the use of diesel oil, electricity, pesticides and field emissions during rice growth period at crop planting stage. Then indirect emissions were from the use of raw coal and crude oil (at raw material mining stage), and coal and electricity (at agricultural materials production stage). Irrigation was the main sources of greenhouse gases emission during field management, followed by tillage, cutting stubble and reaping. NM1 and NM2 treatments decreased greenhouse gases emission at raw material mining and agricultural materials production stages, but significantly increased greenhouse gases emissions at crop planting stage. This subsequently increased greenhouse gases emissions in rice production. Advanced fertilization technologies should be explored to improve N utilization efficiency so as to reduce environmental impact. Also livestock and poultry manures should be harmlessly processed before farmland utilization.
2015, 23(9): 1142-1149.
doi: 10.13930/j.cnki.cjea.150162
Abstract:
In order to investigate the effects of waterlogging stress during jointing and tasseling stages on the grain filling of summer maize, field experiments were conducted during summer maize growth seasons in 2011 and 2012. ‘Xundan20’, a widely cultivated maize variety in the Huang-Huai Plain, was used in the study. Ten treatments were set up at jointing and tasseling stages, including surface waterlogging for 3 or 5 days (JF3 or JF5), and subsurface waterlogging for 5, 7 or 10 days (JW5, JW7 or JW10) at jointing stage; and surface waterlogging for 3 or 5 days (TF3 or TF5), and subsurface waterlogging for 5, 7 or 10 days (TW5, TW7 or TW10) at tasseling stage. In the surface waterlogging treatments, 5 cm depth of water layer was maintained on the soil surface. In the subsurface waterlogging treatments, soil water content was maintained above 90% of field capacity without free water layer on the soil surface. In addition, soil moistures of about 70% and 80% field capacity were set as the control treatments respectively for surface waterlogging (CK1) and subsurface waterlogging (CK2). Logistic regression model was used to simulate the effects of surface waterlogging and subsurface waterlogging on the parameters of grain filling, such as grain filling duration, mean grain filling rate and theoretical maximum 1000-seed weight of summer maize. The results showed that waterlogging stress decreased the duration of grain filling mainly due to decreases in the durations of middle and late grain filling phases. Surface waterlogging for 3 to 5 days decreased grain filling duration by 0.2 to 18.9 days whereas subsurface waterlogging for 5 to 10 days decreased grain filling duration by 2.2 to 7.6 days. Compared with CK, surface waterlogging for 3 days at jointing or tasseling stage resulted in an average increase of 8.2%9.9% in mean grain filling rate. Also for 5 days of surface waterlogging, mean grain filling rate decreased by 10.8%20.9%. Subsurface waterlogging for 5 to 10 days resulted in an average decrease of 0.4%5.2% in mean grain filling rate, where the reduction rate increased with increasing duration of subsurface waterlogging. The theoretical maximum 1000-seed weight and the measured 1000-seed weight increased under 3 days of surface waterlogging, while it reduced under 5 days of surface waterlogging and 5 to 10 days of subsurface waterlogging. The same trends were observed in both the simulated and observed 1000-seed weight. Compared with observed values, simulated results showed that the Logistic regression model overestimated the effect of waterlogging stress on 1000-seed weight.
In order to investigate the effects of waterlogging stress during jointing and tasseling stages on the grain filling of summer maize, field experiments were conducted during summer maize growth seasons in 2011 and 2012. ‘Xundan20’, a widely cultivated maize variety in the Huang-Huai Plain, was used in the study. Ten treatments were set up at jointing and tasseling stages, including surface waterlogging for 3 or 5 days (JF3 or JF5), and subsurface waterlogging for 5, 7 or 10 days (JW5, JW7 or JW10) at jointing stage; and surface waterlogging for 3 or 5 days (TF3 or TF5), and subsurface waterlogging for 5, 7 or 10 days (TW5, TW7 or TW10) at tasseling stage. In the surface waterlogging treatments, 5 cm depth of water layer was maintained on the soil surface. In the subsurface waterlogging treatments, soil water content was maintained above 90% of field capacity without free water layer on the soil surface. In addition, soil moistures of about 70% and 80% field capacity were set as the control treatments respectively for surface waterlogging (CK1) and subsurface waterlogging (CK2). Logistic regression model was used to simulate the effects of surface waterlogging and subsurface waterlogging on the parameters of grain filling, such as grain filling duration, mean grain filling rate and theoretical maximum 1000-seed weight of summer maize. The results showed that waterlogging stress decreased the duration of grain filling mainly due to decreases in the durations of middle and late grain filling phases. Surface waterlogging for 3 to 5 days decreased grain filling duration by 0.2 to 18.9 days whereas subsurface waterlogging for 5 to 10 days decreased grain filling duration by 2.2 to 7.6 days. Compared with CK, surface waterlogging for 3 days at jointing or tasseling stage resulted in an average increase of 8.2%9.9% in mean grain filling rate. Also for 5 days of surface waterlogging, mean grain filling rate decreased by 10.8%20.9%. Subsurface waterlogging for 5 to 10 days resulted in an average decrease of 0.4%5.2% in mean grain filling rate, where the reduction rate increased with increasing duration of subsurface waterlogging. The theoretical maximum 1000-seed weight and the measured 1000-seed weight increased under 3 days of surface waterlogging, while it reduced under 5 days of surface waterlogging and 5 to 10 days of subsurface waterlogging. The same trends were observed in both the simulated and observed 1000-seed weight. Compared with observed values, simulated results showed that the Logistic regression model overestimated the effect of waterlogging stress on 1000-seed weight.
2015, 23(9): 1150-1157.
doi: 10.13930/j.cnki.cjea.150351
Abstract:
An investigation in winter fallow field of double-rice cropping system in the red soil area was carried out in 2012 in a long-term fertilization experiment (started in 1982) site in Hengyang Red Soil Experiment Station of Chinese Academy of Agricultural Sciences to study the species, biomass and biodiversity of weed communities during spring season. The investigated long-term fertilization experiment included five fertilization treatments of application of organic fertilizer, chemical fertilizer and combined application of organic and inorganic fertilizers with the same rates of nitrogen (N), phosphorus (P) and potassium (K) in both the organic and chemical fertilizers, which were no fertilizer (CK), organic fertilizer (composted cattle manure, M), combined application of P and K inorganic fertilizer and organic fertilizer (PKM), application of inorganic N, P, and K fertilizer (NPK), combined application of N, K inorganic fertilizer and organic fertilizer (NKM), combined application of N, P inorganic fertilizer and organic fertilizer (NPM), and combined application of N, P, K inorganic fertilizer and organic fertilizer (NPKM). The results showed that the dominant weed species changed and the total density and total biomass of weed communities increased under combined application of organic and inorganic fertilizers. NKM treatment had the largest number of weed species, while the least weed species number was under NPM treatment. Species diversity index (1.118 6), evenness index (0.732 3) and dominance index (0.629 7) of weed communities under M treatment were larger than those under the other treatments. However, M treatment had the lowest total weed density (297.0 plant0.25m-2). Also NPK treatment had the lowest total weed biomass (58.0 g0.25m-2). Compared with other treatments, NPM treatment significantly decreased diversity, evenness and dominance indexes of weed communities, and had the highest total weed density (539.7 plant0.25m-2) and total weed biomass (109.5 g0.25m-2), respectively. Alopecurus japonicas was the dominant weed species, and had weed density of 428.0 plant0.25m-2 and relative weed density of 79.31% under NPM treatment, which were significantly higher than those of dominant weeds under other treatments. It was noted in this study that total dry biomass of weeds was positively correlated with content of soil alkali-hydrolyzable N (r = 0.703), negatively correlated with soil pH (r = –0.697), and significantly positively correlated with soil available P content (rr?=?0.758). Thus soil P was considered as the main factor responsible for the characteristic changes in weed communities under long-term fertilization modes. The proper regulation of soil pH and contents of soil alkali-hydrolyzable N, soil available P and especially soil available P through different long-term fertilization schemes could effectively managed biomass, density, and biodiversity of weed communities during spring season in winter fallow paddy field in the red soil area.
An investigation in winter fallow field of double-rice cropping system in the red soil area was carried out in 2012 in a long-term fertilization experiment (started in 1982) site in Hengyang Red Soil Experiment Station of Chinese Academy of Agricultural Sciences to study the species, biomass and biodiversity of weed communities during spring season. The investigated long-term fertilization experiment included five fertilization treatments of application of organic fertilizer, chemical fertilizer and combined application of organic and inorganic fertilizers with the same rates of nitrogen (N), phosphorus (P) and potassium (K) in both the organic and chemical fertilizers, which were no fertilizer (CK), organic fertilizer (composted cattle manure, M), combined application of P and K inorganic fertilizer and organic fertilizer (PKM), application of inorganic N, P, and K fertilizer (NPK), combined application of N, K inorganic fertilizer and organic fertilizer (NKM), combined application of N, P inorganic fertilizer and organic fertilizer (NPM), and combined application of N, P, K inorganic fertilizer and organic fertilizer (NPKM). The results showed that the dominant weed species changed and the total density and total biomass of weed communities increased under combined application of organic and inorganic fertilizers. NKM treatment had the largest number of weed species, while the least weed species number was under NPM treatment. Species diversity index (1.118 6), evenness index (0.732 3) and dominance index (0.629 7) of weed communities under M treatment were larger than those under the other treatments. However, M treatment had the lowest total weed density (297.0 plant0.25m-2). Also NPK treatment had the lowest total weed biomass (58.0 g0.25m-2). Compared with other treatments, NPM treatment significantly decreased diversity, evenness and dominance indexes of weed communities, and had the highest total weed density (539.7 plant0.25m-2) and total weed biomass (109.5 g0.25m-2), respectively. Alopecurus japonicas was the dominant weed species, and had weed density of 428.0 plant0.25m-2 and relative weed density of 79.31% under NPM treatment, which were significantly higher than those of dominant weeds under other treatments. It was noted in this study that total dry biomass of weeds was positively correlated with content of soil alkali-hydrolyzable N (r = 0.703), negatively correlated with soil pH (r = –0.697), and significantly positively correlated with soil available P content (rr?=?0.758). Thus soil P was considered as the main factor responsible for the characteristic changes in weed communities under long-term fertilization modes. The proper regulation of soil pH and contents of soil alkali-hydrolyzable N, soil available P and especially soil available P through different long-term fertilization schemes could effectively managed biomass, density, and biodiversity of weed communities during spring season in winter fallow paddy field in the red soil area.
Genotypic variation and environmental effects on yield, quality and agronomic traits of sweet potato
LU Huixiang,
TANG Daobin,
WU Zhengdan,
LUO Kai,
HAN Xu,
JING Fu,
LUO Yulong,
ZHANG Xiaoyong,
ZHANG Kai,
WANG Jichun
2015, 23(9): 1158-1168.
doi: 10.13930/j.cnki.cjea.150363
Abstract:
The development of new sweet potato varieties with high starch and anthocyanin contents in storage roots has been the key objective of sweet potato research. In this study, natural variations in five white-fleshed sweet potato (with white or pale yellow flesh color) varieties (lines) and five purple-fleshed sweet potato (with purple flesh color) varieties (lines) were analyzed for the effects of environments on quality traits of storage roots in 2012 and 2013. Analyses of variance and correlation were conducted for the two types of sweet potato accessions in six regions of Chongqing City. The results showed significant differences (P < 0.05) or extremely significant differences (P < 0.01) in yield-related traits (e.g., fresh yield, starch yield and dry root yield) and quality traits (e.g., starch content, dry matter content and anthocyanin content) among genotypes and environments. For all the tested sweet potato varieties (lines), genotypic effect on starch content was greater than environmental and temporal effects. For white-fleshed sweet potato accessions, environmental effect on yield-related traits was greater than genotypic and temporal effects. For purple-fleshed sweet potato, however, environmental and temporal effects on yield were greater than genotypic effect. While higher yield was obtained at intermediate altitude (i.e., Wanzhou or Youyang) conditions, better palatability was obtained at low altitude (i.e., Hechuan and Beibei) conditions. Furthermore, the grade of palatability at intermediate altitude was higher than that at high altitude (i.e., Qianjiang or Wuxi) conditions. The mean variation coefficients (CV) of morphological traits (e.g., stem diameter, vine length and breach number, CV = 0.30) and yield-related traits (CV = 0.28) were high, those of quality traits (e.g., dry matter content, starch content and palatability) was even much smaller (CV = 0.11), while that of anthocyanin content was also high (CV = 0.28). Correlation analysis suggested extremely positive correlations (r ≥ 0.700) among fresh yield, starch yield and dry root yield of sweet potato. Starch content had extremely positive correlations with dry root yield and starch yield (r ≥ 0.363). For white-fleshed sweet potato accessions, stem diameter had extremely significantly positive correlation with vine length (r = 0.439), extremely significantly negative correlation with starch content (r = 0.433), and significantly negative correlation with starch yield (r = 0.318). For purple-fleshed sweet potato accessions, commodity rate was significantly positively correlated with branch number, starch yield and dry root yield (r = 0.345, 0.368 and 0.357, respectively). In addition, a significantly negative correlation (r = 0.397) was noted between vine length and branch number. It was concluded that affecting factors of yield, quality and agronomic traits of different genotypic accessions of sweet potato were different. Individualized selection and breeding approaches should be adopted on the basis of sweet potato types and breeding targets. The results provided valuable theoretical reference for screening advantageous environmental factors for quality traits formation, improvement of breeding approaches, and cultivation techniques of sweet potato. This could facilitate the promotion of quality improvement of sweet potato.
The development of new sweet potato varieties with high starch and anthocyanin contents in storage roots has been the key objective of sweet potato research. In this study, natural variations in five white-fleshed sweet potato (with white or pale yellow flesh color) varieties (lines) and five purple-fleshed sweet potato (with purple flesh color) varieties (lines) were analyzed for the effects of environments on quality traits of storage roots in 2012 and 2013. Analyses of variance and correlation were conducted for the two types of sweet potato accessions in six regions of Chongqing City. The results showed significant differences (P < 0.05) or extremely significant differences (P < 0.01) in yield-related traits (e.g., fresh yield, starch yield and dry root yield) and quality traits (e.g., starch content, dry matter content and anthocyanin content) among genotypes and environments. For all the tested sweet potato varieties (lines), genotypic effect on starch content was greater than environmental and temporal effects. For white-fleshed sweet potato accessions, environmental effect on yield-related traits was greater than genotypic and temporal effects. For purple-fleshed sweet potato, however, environmental and temporal effects on yield were greater than genotypic effect. While higher yield was obtained at intermediate altitude (i.e., Wanzhou or Youyang) conditions, better palatability was obtained at low altitude (i.e., Hechuan and Beibei) conditions. Furthermore, the grade of palatability at intermediate altitude was higher than that at high altitude (i.e., Qianjiang or Wuxi) conditions. The mean variation coefficients (CV) of morphological traits (e.g., stem diameter, vine length and breach number, CV = 0.30) and yield-related traits (CV = 0.28) were high, those of quality traits (e.g., dry matter content, starch content and palatability) was even much smaller (CV = 0.11), while that of anthocyanin content was also high (CV = 0.28). Correlation analysis suggested extremely positive correlations (r ≥ 0.700) among fresh yield, starch yield and dry root yield of sweet potato. Starch content had extremely positive correlations with dry root yield and starch yield (r ≥ 0.363). For white-fleshed sweet potato accessions, stem diameter had extremely significantly positive correlation with vine length (r = 0.439), extremely significantly negative correlation with starch content (r = 0.433), and significantly negative correlation with starch yield (r = 0.318). For purple-fleshed sweet potato accessions, commodity rate was significantly positively correlated with branch number, starch yield and dry root yield (r = 0.345, 0.368 and 0.357, respectively). In addition, a significantly negative correlation (r = 0.397) was noted between vine length and branch number. It was concluded that affecting factors of yield, quality and agronomic traits of different genotypic accessions of sweet potato were different. Individualized selection and breeding approaches should be adopted on the basis of sweet potato types and breeding targets. The results provided valuable theoretical reference for screening advantageous environmental factors for quality traits formation, improvement of breeding approaches, and cultivation techniques of sweet potato. This could facilitate the promotion of quality improvement of sweet potato.
2015, 23(9): 1169-1177.
doi: 10.13930/j.cnki.cjea.150221
Abstract:
The GGE (genotype main effect plus genotype by environment interaction effect) biplot is the most powerful statistical and visual display tool available for cultivar evaluation, environmental evaluation and mega-envrironment investigation. The versatility of GGE biplot in displaying cultivar stability and high yielding, identifying ideal cultivars and test environments, evaluating the representativeness and discrimination ability of test sites, and differentiating mega- environments have attracted extensive application in analyzing regional trials of many crops. Nevertheless, few reports have focused on the potential loss of fit of GGE biplot models and model adjustment using information ratio (IR). IR is the product of percent variation explained by each principal component and the minor value of degree of freedom of genotypes along with the number of test locatons in GGE biplot analysis of datasets in regional crop trials. As principal component with IR ≥ 1 has useful information, it is a sufficient and necessary condition of GGE model with appropriate goodness of fit to cover all data analysis. In fact, the goodness of fit of GGE biplot models is restricted to the sum of percent variation explained by the first two principal components (PC1 and PC2), rather than the suitable principal components determined by IR. Thus although GGE biplot model is an efficient graphical display of data structure, it is not so efficient to guarantee optimal fitting of effects. Using the GGE biplot method and collected datasets in national regional cotton (Gossypium hirsutum L.) trials in the Yangtze River Valley in 2000?2012, this study showed the effects of IR adjustments of GGE models in maga-environment investigation. The scores of principal components for IR ≥ 1 in 35 groups of regional cotton trials were used to calculate Euclidean distance matrix among the test environments. Also a hierachical cluster analysis was implemented to outline the scheme of differentiation of the mega-environment. A corresponding analysis was also carried out using fixed first two principal components of GGE biplot analysis for the purpose of mutual comparision between GGE biplot model and IR-adjusted GGE model for mega-environment investigation efficiency. The results showed that while only 28.6% was appropriately fitted by GGE biplot model, 68.6% was under-fitted and 2.9% over-fitted in 35 groups of regional cotton trials. The IR-adjusted GGE model enhanced the goodness of fit by 8.7% and reduced loss of fit by 12.2% for under- and over-fitted GGE biplot model trials. Compared with IR-adjusted model, the superiority index of GGE biplot model was 15.9%. This indicated that GGE biplot model performed satisfactorily in depicting the overall pattern of genotype by environment interaction of regional cotton trials. However, the IR-adjusted GGE model was more reliable and had a more precise goodness of fit. The first hierachical mega-environment differentiation by the IR-adjusted GGE model was the same as that of GGE biplot model in terms of identifying cotton planting regions in Nan-Xiang Basin and Sichuan Basin as particular ecological regions. However, they were significantly different in terms of subregion divisions in the middle and lower reaches of the Yangtze River Valley. The mega-environment division scheme based on the IR-adjusted GGE model was of more practical in terms of geographical and ecological factor representation. Thus the study demonstrated an excellent example of the principles and application effects of GGE biplot adjusted with IR. This served as a significant supplement and improvement to GGE biplot application. It also provided the scientific basis and guidline for the application of GGE biplot in mega-environment investigation.
The GGE (genotype main effect plus genotype by environment interaction effect) biplot is the most powerful statistical and visual display tool available for cultivar evaluation, environmental evaluation and mega-envrironment investigation. The versatility of GGE biplot in displaying cultivar stability and high yielding, identifying ideal cultivars and test environments, evaluating the representativeness and discrimination ability of test sites, and differentiating mega- environments have attracted extensive application in analyzing regional trials of many crops. Nevertheless, few reports have focused on the potential loss of fit of GGE biplot models and model adjustment using information ratio (IR). IR is the product of percent variation explained by each principal component and the minor value of degree of freedom of genotypes along with the number of test locatons in GGE biplot analysis of datasets in regional crop trials. As principal component with IR ≥ 1 has useful information, it is a sufficient and necessary condition of GGE model with appropriate goodness of fit to cover all data analysis. In fact, the goodness of fit of GGE biplot models is restricted to the sum of percent variation explained by the first two principal components (PC1 and PC2), rather than the suitable principal components determined by IR. Thus although GGE biplot model is an efficient graphical display of data structure, it is not so efficient to guarantee optimal fitting of effects. Using the GGE biplot method and collected datasets in national regional cotton (Gossypium hirsutum L.) trials in the Yangtze River Valley in 2000?2012, this study showed the effects of IR adjustments of GGE models in maga-environment investigation. The scores of principal components for IR ≥ 1 in 35 groups of regional cotton trials were used to calculate Euclidean distance matrix among the test environments. Also a hierachical cluster analysis was implemented to outline the scheme of differentiation of the mega-environment. A corresponding analysis was also carried out using fixed first two principal components of GGE biplot analysis for the purpose of mutual comparision between GGE biplot model and IR-adjusted GGE model for mega-environment investigation efficiency. The results showed that while only 28.6% was appropriately fitted by GGE biplot model, 68.6% was under-fitted and 2.9% over-fitted in 35 groups of regional cotton trials. The IR-adjusted GGE model enhanced the goodness of fit by 8.7% and reduced loss of fit by 12.2% for under- and over-fitted GGE biplot model trials. Compared with IR-adjusted model, the superiority index of GGE biplot model was 15.9%. This indicated that GGE biplot model performed satisfactorily in depicting the overall pattern of genotype by environment interaction of regional cotton trials. However, the IR-adjusted GGE model was more reliable and had a more precise goodness of fit. The first hierachical mega-environment differentiation by the IR-adjusted GGE model was the same as that of GGE biplot model in terms of identifying cotton planting regions in Nan-Xiang Basin and Sichuan Basin as particular ecological regions. However, they were significantly different in terms of subregion divisions in the middle and lower reaches of the Yangtze River Valley. The mega-environment division scheme based on the IR-adjusted GGE model was of more practical in terms of geographical and ecological factor representation. Thus the study demonstrated an excellent example of the principles and application effects of GGE biplot adjusted with IR. This served as a significant supplement and improvement to GGE biplot application. It also provided the scientific basis and guidline for the application of GGE biplot in mega-environment investigation.
2015, 23(9): 1178-1184.
doi: 10.13930/j.cnki.cjea.150375
Abstract:
Transgenic Bt rice has been developed successfully and has provided an effective and economical control on lepidopterous pests in rice field. Zoobenthos in paddy fields is an important non-target organism for transgenic Bt rice. To understand the safety of transgenic Bt rice on zoobenthos community in paddy fields, the effects of transgenic Cry1Ab/Ac rice on zoobenthos community were studied in paddy fields using the community method. The experiment was conducted in 2-consecutive-year field of transgenic Cry1Ab/Ac rice ‘Huahui No. 1’ (HH1 for short) in Nanchang, Jiangxi Province. The non-transgenic parent rice ‘Minghui 63’ (MH63 for short) was used as control treatment. Benthic animal community in paddy fields was used as bio-indicator. In 2012, some 22 and 25 species of benthic animals were respectively collected in HH1 and MH63 paddy fields. There were 19 species in common and 7 dominant species in zoobenthos communities in HH1 and MH63 paddy fields. The similarity of all the species and the dominant species of zoobenthos communities in HH1 and MH63 habitats were 0.808 5 and 0.833 3, respectively. In 2013, 26 and 28 species of benthic animals were collected in paddy fields planted respectively with HH1 and MH63, comprising of 22 common and 6 dominant species. The similarity of all the species and the dominant species of zoobenthos communities in HH1 and MH63 paddy fields were respectively 0.814 8 and 1.000 0. Analyses of both total and temporal dynamics of community parameters such as the indexes of species richness, individual number, diversity, evenness and dominance in HH1 and MH63 paddy fields in 2012 and 2013 displayed similar rates and trends and with no observed significant difference. Analysis of HH1 field (with 2 consecutive years of cultivation) in Nanchang suggested that transgenic Cry1Ab/Ac rice had no obvious adverse effect on benthic animal community.
Transgenic Bt rice has been developed successfully and has provided an effective and economical control on lepidopterous pests in rice field. Zoobenthos in paddy fields is an important non-target organism for transgenic Bt rice. To understand the safety of transgenic Bt rice on zoobenthos community in paddy fields, the effects of transgenic Cry1Ab/Ac rice on zoobenthos community were studied in paddy fields using the community method. The experiment was conducted in 2-consecutive-year field of transgenic Cry1Ab/Ac rice ‘Huahui No. 1’ (HH1 for short) in Nanchang, Jiangxi Province. The non-transgenic parent rice ‘Minghui 63’ (MH63 for short) was used as control treatment. Benthic animal community in paddy fields was used as bio-indicator. In 2012, some 22 and 25 species of benthic animals were respectively collected in HH1 and MH63 paddy fields. There were 19 species in common and 7 dominant species in zoobenthos communities in HH1 and MH63 paddy fields. The similarity of all the species and the dominant species of zoobenthos communities in HH1 and MH63 habitats were 0.808 5 and 0.833 3, respectively. In 2013, 26 and 28 species of benthic animals were collected in paddy fields planted respectively with HH1 and MH63, comprising of 22 common and 6 dominant species. The similarity of all the species and the dominant species of zoobenthos communities in HH1 and MH63 paddy fields were respectively 0.814 8 and 1.000 0. Analyses of both total and temporal dynamics of community parameters such as the indexes of species richness, individual number, diversity, evenness and dominance in HH1 and MH63 paddy fields in 2012 and 2013 displayed similar rates and trends and with no observed significant difference. Analysis of HH1 field (with 2 consecutive years of cultivation) in Nanchang suggested that transgenic Cry1Ab/Ac rice had no obvious adverse effect on benthic animal community.
2015, 23(9): 1185-1190.
doi: 10.13930/j.cnki.cjea.150056
Abstract:
Understanding antioxidant enzymes activities and other related physiological indexes of cucumber (Cucumis sativus L.) seedling under repeatedly application of insecticides is critical for safe application of pesticides. In order to explore the effects of three chemical pesticides (Deltamethrin, Acetamiprid and Imidacloprid) and one biological pesticide (Isaria fumosorosea) on cucumber seedlings, activities of antioxidant enzymes (SOD, POD and CAT) and contents of malondiadehyde (MDA), proline (Pro) and protein in pesticides stressed cucumber seedlings were investigated under laboratory conditions. The results showed that different insecticides had different effects on antioxidant enzymes activities and related physiological indexes of cucumber seedlings. For cucumber seedlings under stresses of three chemical insecticides for two days, the activities of three antioxidant enzymes were not significantly different from those of the control. When stress was prolonged to four days, the activities of three antioxidant enzymes in cucumber seedlings under Decamethrin and Acetamiprid stresses significantly increased and were obviously different from those of the control. When stress was prolonged to six days, the activities of SOD and POD of cucumber seedlings under stresses of three chemical insecticides increased and significantly differed from those of the control. Among the three chemical insecticides, Decamethrin showed greater effects than the other two chemical insecticides. After eight to ten days of stress, the activities of three antioxidant enzymes of cucumber seedlings began to decrease and return to the normal level. Moreover, the contents of MDA and proline in cucumber seedlings under stresses of three chemical insecticides for four to eight days obviously increased compared with those of the control. When cucumber seedlings were stressed respectively by Acetamiprid and Decamethrin for ten days, MDA content became significantly higher than the control, while proline content declined to the normal level. The three chemical insecticides decreased protein content in cucumber seedlings at two to eight days after chemical insecticides stresses, the biological insecticide, Isaria fumosoprosea did not significantly affected the activities of SOD, POD and CAT along with the contents of MDA, proline and protein. It was noted that the biological insecticide, Isaria fumosoprosea, was relatively safer than the three chemical insecticides. It took a certain period for cucumber seedlings to recover from the harm caused by chemical insecticides.
Understanding antioxidant enzymes activities and other related physiological indexes of cucumber (Cucumis sativus L.) seedling under repeatedly application of insecticides is critical for safe application of pesticides. In order to explore the effects of three chemical pesticides (Deltamethrin, Acetamiprid and Imidacloprid) and one biological pesticide (Isaria fumosorosea) on cucumber seedlings, activities of antioxidant enzymes (SOD, POD and CAT) and contents of malondiadehyde (MDA), proline (Pro) and protein in pesticides stressed cucumber seedlings were investigated under laboratory conditions. The results showed that different insecticides had different effects on antioxidant enzymes activities and related physiological indexes of cucumber seedlings. For cucumber seedlings under stresses of three chemical insecticides for two days, the activities of three antioxidant enzymes were not significantly different from those of the control. When stress was prolonged to four days, the activities of three antioxidant enzymes in cucumber seedlings under Decamethrin and Acetamiprid stresses significantly increased and were obviously different from those of the control. When stress was prolonged to six days, the activities of SOD and POD of cucumber seedlings under stresses of three chemical insecticides increased and significantly differed from those of the control. Among the three chemical insecticides, Decamethrin showed greater effects than the other two chemical insecticides. After eight to ten days of stress, the activities of three antioxidant enzymes of cucumber seedlings began to decrease and return to the normal level. Moreover, the contents of MDA and proline in cucumber seedlings under stresses of three chemical insecticides for four to eight days obviously increased compared with those of the control. When cucumber seedlings were stressed respectively by Acetamiprid and Decamethrin for ten days, MDA content became significantly higher than the control, while proline content declined to the normal level. The three chemical insecticides decreased protein content in cucumber seedlings at two to eight days after chemical insecticides stresses, the biological insecticide, Isaria fumosoprosea did not significantly affected the activities of SOD, POD and CAT along with the contents of MDA, proline and protein. It was noted that the biological insecticide, Isaria fumosoprosea, was relatively safer than the three chemical insecticides. It took a certain period for cucumber seedlings to recover from the harm caused by chemical insecticides.
2015, 23(9): 1191-1198.
doi: 10.13930/j.cnki.cjea.150149
Abstract:
Evaluation of the degree of land destruction in coal mining areas is critical for suitable land reclamation measures. A number of studies have evaluated the degree of land destruction in coal mining areas in China and around the world. Currently, the common evaluation methods used include the extreme conditions method, fuzzy comprehensive evaluation method, geographic information system (GIS)-based statistical evaluation method, and the index method. While these methods can reflect the degree of land destruction in coal mining areas, there still is difference in evaluation results due to no uniform criteria for determining the index weight. For the same evaluation method, evaluation results are different when different methods are used to determine index weight. Therefore, the precise determination of index weight has remained the core issue of evaluation methods, which directly affects the accuracy of evaluation results. The G1 method proposed by Yajun Guo is an empowerment method that deals with consistency issue of analytic hierarchy process (AHP) and other subjective methods. The characteristics of G1 include a reflection of the importance of indicators by subjective sorting without limiting the number of indicators and dispense with checking consistency. However, the G1 method has no clear description for sorting indicators and is hardly consistent in sorting expert comments. In this study, the fuzzy opinion centralized decision was applied to the G1 method to sort expert comments. This comprehensive treatment of the method gave a group of more reasonable indicator sorting. The method was used to determine the weight of each index and then to establish an improved fuzzy comprehensive evaluation method. The final method successfully resolved excessive subjectivity common in the determination of index weight. The improved fuzzy comprehensive evaluation method was then used to evaluate the degree of land destruction in Fukangyuan Coal Mining area in Shanxi Province. According to the types of land damage, the study area was divided into two categories — subsided land and occupied land, which had a total of 5 evaluation units. An evaluation index system was then established and the weights determined using the improved G1 method. The extents of damage of the 5 evaluation units were eventually evaluated. The results showed that 2 of the 5 land units had moderate destruction, 2 had mild destruction and then 1 had severe destruction. The results obtained with the improved evaluation model were consistent with those obtained with other methods. When combined with field research, the improved method had a higher reliability. Compared with the classical fuzzy comprehensive evaluation method, the improved method emphasized scientific weight determination to overcome the shortcomings of the classical method with which the weight distribution was unreasonable for larger numbers of indicators. This meant that the improved fuzzy comprehensive evaluation method was more suitable for application in evaluating the degree of land disruption in coal mining areas. The method was suitable for determining the state of destroyed lands, establishing land reclamation measures, restoring and reconstructing ecological environments, and consolidating land protection programs.
Evaluation of the degree of land destruction in coal mining areas is critical for suitable land reclamation measures. A number of studies have evaluated the degree of land destruction in coal mining areas in China and around the world. Currently, the common evaluation methods used include the extreme conditions method, fuzzy comprehensive evaluation method, geographic information system (GIS)-based statistical evaluation method, and the index method. While these methods can reflect the degree of land destruction in coal mining areas, there still is difference in evaluation results due to no uniform criteria for determining the index weight. For the same evaluation method, evaluation results are different when different methods are used to determine index weight. Therefore, the precise determination of index weight has remained the core issue of evaluation methods, which directly affects the accuracy of evaluation results. The G1 method proposed by Yajun Guo is an empowerment method that deals with consistency issue of analytic hierarchy process (AHP) and other subjective methods. The characteristics of G1 include a reflection of the importance of indicators by subjective sorting without limiting the number of indicators and dispense with checking consistency. However, the G1 method has no clear description for sorting indicators and is hardly consistent in sorting expert comments. In this study, the fuzzy opinion centralized decision was applied to the G1 method to sort expert comments. This comprehensive treatment of the method gave a group of more reasonable indicator sorting. The method was used to determine the weight of each index and then to establish an improved fuzzy comprehensive evaluation method. The final method successfully resolved excessive subjectivity common in the determination of index weight. The improved fuzzy comprehensive evaluation method was then used to evaluate the degree of land destruction in Fukangyuan Coal Mining area in Shanxi Province. According to the types of land damage, the study area was divided into two categories — subsided land and occupied land, which had a total of 5 evaluation units. An evaluation index system was then established and the weights determined using the improved G1 method. The extents of damage of the 5 evaluation units were eventually evaluated. The results showed that 2 of the 5 land units had moderate destruction, 2 had mild destruction and then 1 had severe destruction. The results obtained with the improved evaluation model were consistent with those obtained with other methods. When combined with field research, the improved method had a higher reliability. Compared with the classical fuzzy comprehensive evaluation method, the improved method emphasized scientific weight determination to overcome the shortcomings of the classical method with which the weight distribution was unreasonable for larger numbers of indicators. This meant that the improved fuzzy comprehensive evaluation method was more suitable for application in evaluating the degree of land disruption in coal mining areas. The method was suitable for determining the state of destroyed lands, establishing land reclamation measures, restoring and reconstructing ecological environments, and consolidating land protection programs.
2015, 23(9): 1199-1209.
doi: 10.13930/j.cnki.cjea.150506
Abstract:
With 141 000 km2 area and accounting for approximately 20% of China’s grain production, the North China Plain is one of the most important agricultural regions in China. Agricultural land uses affect land surface energy and water balance. With changes in natural condition and economics, the spatial distribution patterns of crops change accordingly, affecting the quantity and quality of regional food production. It is important to precisely determine the distributions of land areas under different crops. This lays the basis for not only adjustment and optimization of agricultural structure, but also the reduction of agricultural disaster and protection of groundwater resources. As an advanced technique, remote sensing is widely used in crop research in terms of changes in spatial patterns at different spatial and temporal scales. Remote sensing can also be used to accurately monitor crop planting in real time at low cost. To understand the spatiotemporal variations in crop planting in the North China Plain, this paper established a method for classifying agricultural land use using MODIS NDVI and TM/ETM data. Raw 16-day composite NDVI data were firstly processed using HANTS filtering and then combined with multiple cropping index (MCI) to extract planting areas of winter wheat/summer maize, single-cropping maize, forest and fruit trees, and cotton. The planting areas of vegetables and rice were next extracted by supervised classification using the TM/ETM image data. Finally, the spatiotemporal variations in the main crops planting areas in the North China Plain from 2000 to 2013 were analyzed. The results were as follows: 1) The planting areas of the main corps of the study area extracted from MODIS NDVI and TM/ETM data were stable and highly precise. 2) Winter wheat/summer maize mainly distributed in the piedmont plain of Taihang Mountain and in the Yellow River irrigation regions of Shandong and Henan Provinces. While single-cropping maize widely distributed in the north of Hebei Plain, rice was concentrated in Tianjin, Tangshan and along the coast of the Yellow River. Also vegetables mainly distributed in the suburbs whereas forest and fruit trees scattered over major fruit producing areas and around Beijing and Tianjin. Cotton concentrated in the central region of the North China Plain. 3) The planting areas of food crops (wheat, maize and rice) in the North China Plain decreased obviously. However, economic crops (forest and fruit trees, and vegetables) increased significantly. The percentage changes in area of forest and fruit trees, vegetables and rice were respectively 56.45%, 35.76% and 23.16%. Furthermore, vegetables and rice had an obvious shift in planting area. 4) Landscape pattern indexes of area weighted mean patch fractal dimension and Shannon’s evenness index showed that large-scale degree of winter wheat/summer maize planting enhanced in the south of Hebei Plain, while the planting area of winter wheat/summer maize increased in North Henan. Because different planting areas of several kinds of economic crops in the north of North Henan increased, regional crop diversity index increased. The results provided a critical reference for adjusting agricultural planting structure and reasonable utilization of resources.
With 141 000 km2 area and accounting for approximately 20% of China’s grain production, the North China Plain is one of the most important agricultural regions in China. Agricultural land uses affect land surface energy and water balance. With changes in natural condition and economics, the spatial distribution patterns of crops change accordingly, affecting the quantity and quality of regional food production. It is important to precisely determine the distributions of land areas under different crops. This lays the basis for not only adjustment and optimization of agricultural structure, but also the reduction of agricultural disaster and protection of groundwater resources. As an advanced technique, remote sensing is widely used in crop research in terms of changes in spatial patterns at different spatial and temporal scales. Remote sensing can also be used to accurately monitor crop planting in real time at low cost. To understand the spatiotemporal variations in crop planting in the North China Plain, this paper established a method for classifying agricultural land use using MODIS NDVI and TM/ETM data. Raw 16-day composite NDVI data were firstly processed using HANTS filtering and then combined with multiple cropping index (MCI) to extract planting areas of winter wheat/summer maize, single-cropping maize, forest and fruit trees, and cotton. The planting areas of vegetables and rice were next extracted by supervised classification using the TM/ETM image data. Finally, the spatiotemporal variations in the main crops planting areas in the North China Plain from 2000 to 2013 were analyzed. The results were as follows: 1) The planting areas of the main corps of the study area extracted from MODIS NDVI and TM/ETM data were stable and highly precise. 2) Winter wheat/summer maize mainly distributed in the piedmont plain of Taihang Mountain and in the Yellow River irrigation regions of Shandong and Henan Provinces. While single-cropping maize widely distributed in the north of Hebei Plain, rice was concentrated in Tianjin, Tangshan and along the coast of the Yellow River. Also vegetables mainly distributed in the suburbs whereas forest and fruit trees scattered over major fruit producing areas and around Beijing and Tianjin. Cotton concentrated in the central region of the North China Plain. 3) The planting areas of food crops (wheat, maize and rice) in the North China Plain decreased obviously. However, economic crops (forest and fruit trees, and vegetables) increased significantly. The percentage changes in area of forest and fruit trees, vegetables and rice were respectively 56.45%, 35.76% and 23.16%. Furthermore, vegetables and rice had an obvious shift in planting area. 4) Landscape pattern indexes of area weighted mean patch fractal dimension and Shannon’s evenness index showed that large-scale degree of winter wheat/summer maize planting enhanced in the south of Hebei Plain, while the planting area of winter wheat/summer maize increased in North Henan. Because different planting areas of several kinds of economic crops in the north of North Henan increased, regional crop diversity index increased. The results provided a critical reference for adjusting agricultural planting structure and reasonable utilization of resources.
WANG Heting,
DONG Hui,
QI Longchang,
LI Xuesong,
WANG Teng,
SONG He,
CHEN Song,
DONG Zhaorong,
ZHANG Xiufu
2015, 23(9): 1210-1214.
doi: 10.13930/j.cnki.cjea.150130
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：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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