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
Soil and water loss has been a major environmental problem in the Danjiangkou Reservoir Region.A study of 14°sloping farmland was performed on impact of different contour hedgerows on runoff,losses of soil and nu...Soil and water loss has been a major environmental problem in the Danjiangkou Reservoir Region.A study of 14°sloping farmland was performed on impact of different contour hedgerows on runoff,losses of soil and nutrients during 2008 and 2011,with five treatments and three replications.The winter wheat and summer maize were used as the test crops.Treatments consisted of four hedgerows:Amorpha(Amorpha fruticosa L.),Honeysuckle(Lonicera japonica Thunb.),Day-lily flower(Hemerocallis citrina Baroni.),and Sabaigrass(Eulaliopsis binata),and a control without hedgerow.Result showed that the runoff under the control treatment was much higher than that of hedgerows.Amorpha could reduce the runoff by 35.2%compared with the control.Soil losses in four hedgerows showed significant reduction in four years(e.g.,Amorpha:78.3%;Honeysuckle:77.1%).Nutrient losses in winter were much higher than that in summer,especially total nitrogen,total phosphorus and total potassium,even though there was an abundant precipitation in summer.Hedgerows greatly affected the soil and nutrient losses on slopping farmland compared with the control treatment,especially Amorpha treatment.The present study found that the Amorpha could be used as the hedgerow species for reducing soil and water loss in the Danjiangkou Reservoir Region.展开更多
The disease types, symptom characteristics, pathogenesis and ecological control technology of hedgerow commonly used in landscape greening in Nanjing, Zhenjiang, Changzhou, Wuxi and Suzhou were systematically studied....The disease types, symptom characteristics, pathogenesis and ecological control technology of hedgerow commonly used in landscape greening in Nanjing, Zhenjiang, Changzhou, Wuxi and Suzhou were systematically studied. The results showed that there were 10 kinds of common diseases of flowers and shrubs in landscape greening in five cities of southern Jiangsu. Among them, 8 were caused by deuteromycotina and 2 were caused by subphylum basidiomycetes. It was pointed out that the disease regularity was directly related to the pathogenic bacteria, temperature and humidity, microclimate and hedgerow growth. For the first time, the ecological control method of hedgerow disease which focused on ecological health maintenance was put forward.展开更多
Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year...Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year study was conducted to investigate the effects of contour hedgerow intercropping on nutrient loss from sloping farmland in this area.Four treatments were applied:(1) Maize + Soybean,(2) Maize,(3) Maize + Alfalfa,and(4) Maize + Hemerocallis citrina Baroni.Results indicated that nutrient loss in the control treatment(Maize) was serious,especially the average loss flux of total nitrogen(2245.8 mg) and total phosphate(2434.2 mg) in a typical rainfall event.However,the nutrient losses by runoff in the other three treatments with contour hedgerow intercropping showed significant reduction.Compared with the control treatment,the total nitrogen loss in the Alfalfa and Hemerocallis citrina Baroni decreased by 80.9% and 85.0%,respectively,and the total phosphorus loss in the two treatments decreased by 91.2% and 92.5%,respectively.Therefore,it is concluded that nutrient losses could be reduced by using contour hedgerows in the Three Gorges Region.Reducing runoff volume and sediment loss was the main mechanisms of contour hedgerow intercropping to reduce nutrient loss.展开更多
A litterbag experiment of 12 weeks was conducted to study nitrogen mineralization process of prunings of six nitrogen-fixing hedgerow species in a dry valley of the Jinsha River. Prunings were incorporated into soil o...A litterbag experiment of 12 weeks was conducted to study nitrogen mineralization process of prunings of six nitrogen-fixing hedgerow species in a dry valley of the Jinsha River. Prunings were incorporated into soil or used as mulch. The results indicated that pruning N of the six hedgerow species was mineralized fast in the first week and then decreased slowly in the rest of the study period. When prunings were incorporated into soil, the amount of nitrogen mineralized by the end of the first week accounted for 69.9%, 58.2%, 54.5%, 43.0%, 29.6% and 20.6% of the total N in prunings of Desmodium rensonii, Tephrosia Candida, Leucaena leucocephala, Albizia yunnanensis, Acacia dealbata, and Acacia mearnsii, respectively. When prunings of L. leucocephala were used as mulch materials, the amount of nitrogen mineralized in the first week was 16.2% less than that of prunings incorporated into soil. The mineralization pattern of pruning N could be simulated by an exponent model Nt% = N01% (1 ?exp(梜1t))+ No2% (1 ?exp(梜2t) where Nt% is cumulative mineralized N in time t, N01 % and No2 % are readily and less readily mineralizable N in prunings, respectively, and k1 and k2 are rate constants. A half-life period of pruning nitrogen mineralization could also be determined by this model. The nitrogen content in the pruning residues decreased quickly in the first week but fluctuated thereafter. The initial C/N ratio was negatively related to the mineralization rate of prunings.展开更多
Given the impermeability,larger dosage,and higher drift of pesticides used in modern hedgerow vine canopies,a novel tunnel-convective air-assisted spraying technology was proposed.Mechanized spraying equipment with hi...Given the impermeability,larger dosage,and higher drift of pesticides used in modern hedgerow vine canopies,a novel tunnel-convective air-assisted spraying technology was proposed.Mechanized spraying equipment with high penetration and low drift was developed.The air-assisted system of this equipment was centrosymmetric,and the fan type was cross-flow.The fan outlet width was 138 mm and the air duct’s main body followed a logarithmic spiral profile,based on parallel flow theory.The external diameter of the impeller was 157 mm,which was fixed into a barrel structure by 23 strong forward-curved blades,each being 1 mm thick.The central angle of the blades was 108°,and the ratio of the internal and external diameters was 0.81.The impeller and air duct served as guides to circulate and reciprocate airflow around the crown,forming a tunnel-convective air-assisted to the vine.Using MATLAB interpolation,the airflow trajectory of the air convection circulation in the door-shaped cover was obtained.The velocity field distribution test showed that,in the case of a canopy,there were tunnel-convective circulating airflows with high velocity on both sides and uniform velocity in the middle of the canopy.Due to the tunnel-convective air-assisted spraying technology,the vertical distribution uniformity of spray deposition has been significantly improved,spray penetration has been enhanced,penetrability has been effectively improved,and droplets on the ground and in the air have been significantly reduced.The results of this study can assist in providing further optimization and improvement of plant protection machinery.The new tunnel-convective air-assisted spraying technology may be a more favorable choice for future spray applications and the environment.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Soil and water loss has been a major environmental problem in the Danjiangkou Reservoir Region.A study of 14°sloping farmland was performed on impact of different contour hedgerows on runoff,losses of soil and nutrients during 2008 and 2011,with five treatments and three replications.The winter wheat and summer maize were used as the test crops.Treatments consisted of four hedgerows:Amorpha(Amorpha fruticosa L.),Honeysuckle(Lonicera japonica Thunb.),Day-lily flower(Hemerocallis citrina Baroni.),and Sabaigrass(Eulaliopsis binata),and a control without hedgerow.Result showed that the runoff under the control treatment was much higher than that of hedgerows.Amorpha could reduce the runoff by 35.2%compared with the control.Soil losses in four hedgerows showed significant reduction in four years(e.g.,Amorpha:78.3%;Honeysuckle:77.1%).Nutrient losses in winter were much higher than that in summer,especially total nitrogen,total phosphorus and total potassium,even though there was an abundant precipitation in summer.Hedgerows greatly affected the soil and nutrient losses on slopping farmland compared with the control treatment,especially Amorpha treatment.The present study found that the Amorpha could be used as the hedgerow species for reducing soil and water loss in the Danjiangkou Reservoir Region.
文摘The disease types, symptom characteristics, pathogenesis and ecological control technology of hedgerow commonly used in landscape greening in Nanjing, Zhenjiang, Changzhou, Wuxi and Suzhou were systematically studied. The results showed that there were 10 kinds of common diseases of flowers and shrubs in landscape greening in five cities of southern Jiangsu. Among them, 8 were caused by deuteromycotina and 2 were caused by subphylum basidiomycetes. It was pointed out that the disease regularity was directly related to the pathogenic bacteria, temperature and humidity, microclimate and hedgerow growth. For the first time, the ecological control method of hedgerow disease which focused on ecological health maintenance was put forward.
基金by the National Science & Technology Pillar Program (Grant No. 2009ZX07104-002)the CAS Actionplan for West Development (GrantNo. KZCX2-XB3-09)the Natural Science Foundation of China (Grant No. 40901255)
文摘Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year study was conducted to investigate the effects of contour hedgerow intercropping on nutrient loss from sloping farmland in this area.Four treatments were applied:(1) Maize + Soybean,(2) Maize,(3) Maize + Alfalfa,and(4) Maize + Hemerocallis citrina Baroni.Results indicated that nutrient loss in the control treatment(Maize) was serious,especially the average loss flux of total nitrogen(2245.8 mg) and total phosphate(2434.2 mg) in a typical rainfall event.However,the nutrient losses by runoff in the other three treatments with contour hedgerow intercropping showed significant reduction.Compared with the control treatment,the total nitrogen loss in the Alfalfa and Hemerocallis citrina Baroni decreased by 80.9% and 85.0%,respectively,and the total phosphorus loss in the two treatments decreased by 91.2% and 92.5%,respectively.Therefore,it is concluded that nutrient losses could be reduced by using contour hedgerows in the Three Gorges Region.Reducing runoff volume and sediment loss was the main mechanisms of contour hedgerow intercropping to reduce nutrient loss.
基金Project supported jointly by the Chengdu Di Ao Science Foundation and the Sichuan Provincial Science Foundation for Young Scient
文摘A litterbag experiment of 12 weeks was conducted to study nitrogen mineralization process of prunings of six nitrogen-fixing hedgerow species in a dry valley of the Jinsha River. Prunings were incorporated into soil or used as mulch. The results indicated that pruning N of the six hedgerow species was mineralized fast in the first week and then decreased slowly in the rest of the study period. When prunings were incorporated into soil, the amount of nitrogen mineralized by the end of the first week accounted for 69.9%, 58.2%, 54.5%, 43.0%, 29.6% and 20.6% of the total N in prunings of Desmodium rensonii, Tephrosia Candida, Leucaena leucocephala, Albizia yunnanensis, Acacia dealbata, and Acacia mearnsii, respectively. When prunings of L. leucocephala were used as mulch materials, the amount of nitrogen mineralized in the first week was 16.2% less than that of prunings incorporated into soil. The mineralization pattern of pruning N could be simulated by an exponent model Nt% = N01% (1 ?exp(梜1t))+ No2% (1 ?exp(梜2t) where Nt% is cumulative mineralized N in time t, N01 % and No2 % are readily and less readily mineralizable N in prunings, respectively, and k1 and k2 are rate constants. A half-life period of pruning nitrogen mineralization could also be determined by this model. The nitrogen content in the pruning residues decreased quickly in the first week but fluctuated thereafter. The initial C/N ratio was negatively related to the mineralization rate of prunings.
基金the National Natural Science Foundation of China(Grant No.51805271)Jiangsu Agricultural Science and Technology Innovation Fund(CX203172,CX181007)+1 种基金‘Qinglan Project’of Jiangsu Province(QLGC)the Fundamental Research Funds for the Central Universities(KYXK2021001).
文摘Given the impermeability,larger dosage,and higher drift of pesticides used in modern hedgerow vine canopies,a novel tunnel-convective air-assisted spraying technology was proposed.Mechanized spraying equipment with high penetration and low drift was developed.The air-assisted system of this equipment was centrosymmetric,and the fan type was cross-flow.The fan outlet width was 138 mm and the air duct’s main body followed a logarithmic spiral profile,based on parallel flow theory.The external diameter of the impeller was 157 mm,which was fixed into a barrel structure by 23 strong forward-curved blades,each being 1 mm thick.The central angle of the blades was 108°,and the ratio of the internal and external diameters was 0.81.The impeller and air duct served as guides to circulate and reciprocate airflow around the crown,forming a tunnel-convective air-assisted to the vine.Using MATLAB interpolation,the airflow trajectory of the air convection circulation in the door-shaped cover was obtained.The velocity field distribution test showed that,in the case of a canopy,there were tunnel-convective circulating airflows with high velocity on both sides and uniform velocity in the middle of the canopy.Due to the tunnel-convective air-assisted spraying technology,the vertical distribution uniformity of spray deposition has been significantly improved,spray penetration has been enhanced,penetrability has been effectively improved,and droplets on the ground and in the air have been significantly reduced.The results of this study can assist in providing further optimization and improvement of plant protection machinery.The new tunnel-convective air-assisted spraying technology may be a more favorable choice for future spray applications and the environment.