A field experiment was carried out to evaluate the effects of drip fertigation combined with plant hedgerows on nitrogen and phosphorus runoff losses in intensive pear orchards in the Tai Lake Basin.Nitrogen and phosp...A field experiment was carried out to evaluate the effects of drip fertigation combined with plant hedgerows on nitrogen and phosphorus runoff losses in intensive pear orchards in the Tai Lake Basin.Nitrogen and phosphorus runoff over a whole year were measured by using successional runoff water collection devices.The four experimental treatments were conventional fertilization(CK),drip fertigation(DF),conventional fertilization combined with plant hedgerows(C+H),and drip fertigation combined with plant hedgerows(D+H).The results from one year of continuous monitoring showed a significant positive correlation between precipitation and surface runoff discharge.Surface runoff discharge under the treatments without plant hedgerows totaled 15.86%of precipitation,while surface runoff discharge under the treatments with plant hedgerows totaled 12.82%of precipitation.Plant hedgerows reduced the number of runoff events and the amount of surface runoff.Precipitation is the main driving force for the loss of nitrogen and phosphorus in surface runoff,and fertilization is an important factor affecting the losses of nitrogen and phosphorus.In CK,approximately 7.36%of nitrogen and 2.63%of phosphorus from fertilization entered the surface water through runoff.Drip fertigation reduced the accumulation of nitrogen and phosphorus in the surface soil and lowered the runoff loss concentrations of total nitrogen(TN)and total phosphorus(TP).Drip fertigation combined with plant hedgerows significantly reduced the overall TN and TP losses by 45.38 and 36.81%,respectively,in comparison to the CK totals.Drip fertigation increased the vertical migration depth of nitrogen and phosphorus nutrients and reduced the accumulation of nitrogen and phosphorus in the surface soil,which increased the pear yield.The promotion of drip fertigation combined with plant hedgerows will greatly reduce the losses of nitrogen and phosphorus to runoff and maintain the high fruit yields in the intensive orchards of the Tai Lake Basin.展开更多
Distribution characteristics of fish assemblages and environmental variation in emerged plant, floating-leaved plant and blank habitats were studied. Emergent plant habitat supported the greatest fish biomass, density...Distribution characteristics of fish assemblages and environmental variation in emerged plant, floating-leaved plant and blank habitats were studied. Emergent plant habitat supported the greatest fish biomass, density and body size, followed by floating-leaved plant habitat, and those of blank habitat was the lowest. Transparency of emergent plant habitat decreased during the period, but of blank habitat increased. Species number of dominant fish of emergent plant habitat compared to the others decreased from four species, i.e., Hemicculter leuciclus, Pseudobrama simoni, Carassius auratus and Ophicephalus argus in May to the single one, C. auratus in September. Those of blank habitat increased from two species, H. leuciclus and Pseudorasbora parva to four species, H. leuciclus, C. auratus, P. parva and O. argus. This result suggested that emergent plant with excessively high density could worsen habitat physical and chemical conditions, resulted in the fish’s emigration to unvegetated area. Those of floating-leaved plant habitat from two species, Cultrichthys erythropterus and P. simoni, changed into four species, C. erythropterus, P. simoni, H. leuciclus and P. parva. The increasing structure complexity and biomass of floating-leaved macrophyte promoted the increase of dominant fish species number with seasonal change. C. auratus, C. erythropterus and H. leuciclus displayed special preferences on emergent plant, floating-leaved plant and blank habitats respectively. Fish’s special habitat preference was determined by plant physical morphology, habitat characteristics and fish breeding habits.展开更多
Ensuring food safety while reducing agricultural non-point source pollution is quite challenging,especially in developing and underdeveloped countries.Effective systematic strategies and comprehensive technologies nee...Ensuring food safety while reducing agricultural non-point source pollution is quite challenging,especially in developing and underdeveloped countries.Effective systematic strategies and comprehensive technologies need to be developed for agricultural non-point source pollution control at the watershed scale to improve surface water quality.In this review,a proposal is made for a full time-space governance strategy that prioritizes source management followed by endpoint water pollution control.The 4R chain technology system is specifically reviewed,including source reduction,process retention,nutrient reuse and water restoration.The 4R chain technology system with the full time-space governance strategy was applied at the scale of an administrative village and proved to be a feasible solution for reducing agricultural non-point source pollution in China.In the future,a monitoring system needs to be established to trace N and P transport.Additionally,new smart fertilizer and intelligent equipment need to be developed,and relevant governance standards and supportive policies need to be set to enhance the efficacy of agricultural non-point source pollution control.展开更多
Dear Editor,Rice is an important staple food crop in Asia,but the anaerobic soil conditions in rice fields cause emission of the potent greenhouse gas,methane(CH)(Le Mer and Roger,2001),and promote the accumulation of...Dear Editor,Rice is an important staple food crop in Asia,but the anaerobic soil conditions in rice fields cause emission of the potent greenhouse gas,methane(CH)(Le Mer and Roger,2001),and promote the accumulation of arsenic(As)in the grain(Le Mer and Roger,2001;Khanam et al.,2020).To facilitate sustainable agriculture,using wastewater as an organic fertilizer is essential for reducing wastewater treatment-associated energy consumption and the recycling of wastewater nutrients(Zou et al.,2009).展开更多
The DeNitrification–DeComposition(DNDC)model is a process model with a series of carbon and nitrogen biogeochemistry in agro-ecosystems.It incorporates the driving factors of the ecological environment and aims to si...The DeNitrification–DeComposition(DNDC)model is a process model with a series of carbon and nitrogen biogeochemistry in agro-ecosystems.It incorporates the driving factors of the ecological environment and aims to simulate the carbon and nitrogen cycle in the terrestrial ecosystem.Furthermore,the model can be applied effectively in a paddy ecosystem.Based on an investigation and literature review,this study summarized and analyzed the impact of agricultural practices such aswatermanagement,fertilizer application,and strawincorporation on greenhouse gas emissions and soil carbon storage.After years of improvement,the DNDC model can presently be used effectively to evaluate the carbon sequestration and emissions mitigation potential of various agricultural practices.However,the related details of scientific processes of agricultural management,such as biochar incorporation and plastic mulching in paddy fields,should be added or modified and combined with experimental cases of actual agricultural practices to complete the calibration of the model,provide theoretical support for its promotion,and establish a reliable method of evaluating carbon sequestration and emissions mitigation in paddy fields.展开更多
基金supported by the International S&T Cooperation Program of Shanghai,China(20390731200)the Major Science and Technology Program for Water Pollution Control and Treatment,China(2017ZX07205)。
文摘A field experiment was carried out to evaluate the effects of drip fertigation combined with plant hedgerows on nitrogen and phosphorus runoff losses in intensive pear orchards in the Tai Lake Basin.Nitrogen and phosphorus runoff over a whole year were measured by using successional runoff water collection devices.The four experimental treatments were conventional fertilization(CK),drip fertigation(DF),conventional fertilization combined with plant hedgerows(C+H),and drip fertigation combined with plant hedgerows(D+H).The results from one year of continuous monitoring showed a significant positive correlation between precipitation and surface runoff discharge.Surface runoff discharge under the treatments without plant hedgerows totaled 15.86%of precipitation,while surface runoff discharge under the treatments with plant hedgerows totaled 12.82%of precipitation.Plant hedgerows reduced the number of runoff events and the amount of surface runoff.Precipitation is the main driving force for the loss of nitrogen and phosphorus in surface runoff,and fertilization is an important factor affecting the losses of nitrogen and phosphorus.In CK,approximately 7.36%of nitrogen and 2.63%of phosphorus from fertilization entered the surface water through runoff.Drip fertigation reduced the accumulation of nitrogen and phosphorus in the surface soil and lowered the runoff loss concentrations of total nitrogen(TN)and total phosphorus(TP).Drip fertigation combined with plant hedgerows significantly reduced the overall TN and TP losses by 45.38 and 36.81%,respectively,in comparison to the CK totals.Drip fertigation increased the vertical migration depth of nitrogen and phosphorus nutrients and reduced the accumulation of nitrogen and phosphorus in the surface soil,which increased the pear yield.The promotion of drip fertigation combined with plant hedgerows will greatly reduce the losses of nitrogen and phosphorus to runoff and maintain the high fruit yields in the intensive orchards of the Tai Lake Basin.
文摘Distribution characteristics of fish assemblages and environmental variation in emerged plant, floating-leaved plant and blank habitats were studied. Emergent plant habitat supported the greatest fish biomass, density and body size, followed by floating-leaved plant habitat, and those of blank habitat was the lowest. Transparency of emergent plant habitat decreased during the period, but of blank habitat increased. Species number of dominant fish of emergent plant habitat compared to the others decreased from four species, i.e., Hemicculter leuciclus, Pseudobrama simoni, Carassius auratus and Ophicephalus argus in May to the single one, C. auratus in September. Those of blank habitat increased from two species, H. leuciclus and Pseudorasbora parva to four species, H. leuciclus, C. auratus, P. parva and O. argus. This result suggested that emergent plant with excessively high density could worsen habitat physical and chemical conditions, resulted in the fish’s emigration to unvegetated area. Those of floating-leaved plant habitat from two species, Cultrichthys erythropterus and P. simoni, changed into four species, C. erythropterus, P. simoni, H. leuciclus and P. parva. The increasing structure complexity and biomass of floating-leaved macrophyte promoted the increase of dominant fish species number with seasonal change. C. auratus, C. erythropterus and H. leuciclus displayed special preferences on emergent plant, floating-leaved plant and blank habitats respectively. Fish’s special habitat preference was determined by plant physical morphology, habitat characteristics and fish breeding habits.
基金supported by grants from the National Key Research and Development Program of China(2021YFD1700803)Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(19)1007).
文摘Ensuring food safety while reducing agricultural non-point source pollution is quite challenging,especially in developing and underdeveloped countries.Effective systematic strategies and comprehensive technologies need to be developed for agricultural non-point source pollution control at the watershed scale to improve surface water quality.In this review,a proposal is made for a full time-space governance strategy that prioritizes source management followed by endpoint water pollution control.The 4R chain technology system is specifically reviewed,including source reduction,process retention,nutrient reuse and water restoration.The 4R chain technology system with the full time-space governance strategy was applied at the scale of an administrative village and proved to be a feasible solution for reducing agricultural non-point source pollution in China.In the future,a monitoring system needs to be established to trace N and P transport.Additionally,new smart fertilizer and intelligent equipment need to be developed,and relevant governance standards and supportive policies need to be set to enhance the efficacy of agricultural non-point source pollution control.
基金supported by the Yashima Environment Technology Foundation and partly by a Grant-inAid for Young Scientists(No.20K19994)Scientific Research(C)(No.17K00594)Fostering Joint International Research(B)(No.18KK0288)from the Japan Society for the Promotion of Science(JSPS)。
文摘Dear Editor,Rice is an important staple food crop in Asia,but the anaerobic soil conditions in rice fields cause emission of the potent greenhouse gas,methane(CH)(Le Mer and Roger,2001),and promote the accumulation of arsenic(As)in the grain(Le Mer and Roger,2001;Khanam et al.,2020).To facilitate sustainable agriculture,using wastewater as an organic fertilizer is essential for reducing wastewater treatment-associated energy consumption and the recycling of wastewater nutrients(Zou et al.,2009).
基金This study was financed by the National Key Research and Development Program of China,China(2017YFD0800204)Shanghai Agriculture Applied Technology Development Program,China(G2016060301 and 2018(1-3)).
文摘The DeNitrification–DeComposition(DNDC)model is a process model with a series of carbon and nitrogen biogeochemistry in agro-ecosystems.It incorporates the driving factors of the ecological environment and aims to simulate the carbon and nitrogen cycle in the terrestrial ecosystem.Furthermore,the model can be applied effectively in a paddy ecosystem.Based on an investigation and literature review,this study summarized and analyzed the impact of agricultural practices such aswatermanagement,fertilizer application,and strawincorporation on greenhouse gas emissions and soil carbon storage.After years of improvement,the DNDC model can presently be used effectively to evaluate the carbon sequestration and emissions mitigation potential of various agricultural practices.However,the related details of scientific processes of agricultural management,such as biochar incorporation and plastic mulching in paddy fields,should be added or modified and combined with experimental cases of actual agricultural practices to complete the calibration of the model,provide theoretical support for its promotion,and establish a reliable method of evaluating carbon sequestration and emissions mitigation in paddy fields.
