A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP...A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK＞MNP＞MN＞NPK＞NP＞M＞N＞the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N＞P＞K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.展开更多
This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. Th...This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. The results showed that incomes, residual nitrogen in soil, and the loss of nitrogen in surface water in rice-garlic system were higher than those in rice-fava bean system. There were positive correlations between the nitrogen loss of farmland, nitrogen inputs, residual nitrogen in soil, and incomes of farmland. Economic benefits and environment benefits are both appropriate, if the area of rice-garlic system would be reduced to 53% and the area of rice-fava bean system increased to 36% of total cropping area in the investigated watershed. Adjustment of planting structure and introduction of reasonable rotation systems is considered an effective measure of controlling agricultural non-point pollution in watersheds of Erhai Lake.展开更多
pH, exchangeable Ca2+ and Mg2+ of soil can influence the yield and quality of flue-cured tobacco. Xuancheng city is the dominant tobacco-planting region in Anhui province since 2008. A general soil survey was conducte...pH, exchangeable Ca2+ and Mg2+ of soil can influence the yield and quality of flue-cured tobacco. Xuancheng city is the dominant tobacco-planting region in Anhui province since 2008. A general soil survey was conducted in Xuancheng city to understand the current situations of pH, exchangeable Ca2+ and Mg2+ of farmlands under tobacco-rice rotation and to decide whether continuous applying dolomite powders to abate soil acidification. In total 124 topsoil samples (0-20 cm) were collected from the typical farmlands and soil pH, exchangeable Ca2+ and Mg2+ were measured. The results showed that soil pH and Ca2+ and Mg2+ in Xuancheng city were generally in the suitable grades, pH ranged from 4.56 to 8.42 with an average of 5.87, exchangeable Ca2+ ranged from 1.01 cmol(1/2Ca2+) kg-1 to 100.55 cmol(1/2Ca2+) kg-1 with an average of 11.07 cmol(1/2Ca2+) kg-1, and exchangeable Mg2+ ranged from 0.14 cmol(1/2Mg2+) kg-1 to 2.86 cmol(1/2Mg2+) kg-1 with an average of 0.81 cmol(1/2Mg2+) kg-1, all spanned from the low grades to the high grades. To the whole Xuancheng city, 37.10%, 62.10% and 72.58% of the surveyed farmlands were in the low grades of pH, exchangeable Ca2+ and Mg2+, respectively, while 52.42%, 25.00% and 20.97% of the farmlands were in the suitable grades, respectively. pH had an extremely significantly positive Napierian logarithm correlation with exchangeable Ca2+ and an extremely significantly positive power correlation with exchangeable Mg2+. In total about 338.2 kg·hm-2 of Ca2+ and 202.4 kg·hm-2 of Mg2+ are annually input into the farmlands, while about 110.4 kg·hm-2 of Ca2+ and 7.4 kg·hm-2 of Mg2+ are annually moved out from the farmlands, exchangeable Ca2+ and Mg2+ were annually increased by 225.2 kg·hm-2 and 187.6 kg·hm-2 in the farmlands, respectively. It is necessary to monitor the farmlands dynamically in order to decide whether continuous applying dolomite powders which should be dependent upon the specific conditions of individual farmlands.展开更多
[Objective] Nitrogen and phosphorus losses of surface runoff in various crop rotation systems in the north of Erhai Lake basin were studied with the objective to provide references for risk evaluation of environmental...[Objective] Nitrogen and phosphorus losses of surface runoff in various crop rotation systems in the north of Erhai Lake basin were studied with the objective to provide references for risk evaluation of environmental pollution and formulating countermeasures to control the nonpoint source pollution from agriculture.[Method] Water samples collected in four typical crop rotation systems distributed in seven towns（townships） in the north of Erhai Lake basin were investigated,as well as the fertilizer input,to explore the dynamic change of nitrogen and phosphorus content in surface water of farmland and ditch water,and the correlation between fertilizer input and the concentrations of nitrogen and phosphorus in the surface water of farmland and in the ditch water.[Result] The results showed that nitrogen loss in surface water of farmland in different crop rotation systems differed greatly,and the risk of nitrogen loss was 38% lower in broad bean-rice crop rotation than that in garlic-rice crop rotation.The water soluble nitrogen was the primary form of nitrogen loss.The content of water soluble nitrogen was significantly higher in garlic-rice crop rotation than that in the other rotation systems,and the concentrations of nitrogen in the surface water of farmland in different crop rotation systems followed the sequence below：garlic-rice crop rotationryegrass-rice crop rotationbroad bean-rice crop rotationrape-rice crop rotation.The loss of phosphorus in the surface water of farmland was relatively low and phosphorus combined with silt was the primary form for phosphorus loss.There was no significant difference of the loss of various forms of phosphorus in different crop rotation systems.The contents of total nitrogen and total phosphorus in the surface water of farmland were higher than that in ditch water,with increasing rates of total nitrogen and total phosphorus in ditch water of 72% and 82%,respectively.Topdressing was the critical reason for the high concentrations of nitrogen and phosphorus in the surface water,which also caused the increasing load to the ditch water.[Conclusion] Both the nitrogen and phosphorus loss were the highest in garlic-rice crop rotation.Reasonable crop rotation systems should be established based on both the environmental and economic benefits.This study provided references for controlling the nonpoint source pollution of farmland and improving the water quality of Erhai Lake.展开更多
Crop modelling can facilitate researchers＇ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 （DSSAT） m...Crop modelling can facilitate researchers＇ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 （DSSAT） model together with the CENTURT soil model were employed to investigate the effect of low nitrogen （N） input on wheat （Triticum aestivum L.） yield, grain N concentration and soil organic carbon （SOC） in a long-term experiment （19 years） under a wheat-maize （Zea mays L.） rotation at Changping, Beijing, China. There were two treatments including NO （no N application） and N150 （150 kg N ha-1） before wheat and maize planting, with phosphorus （P） and potassium （K） basal fertilizers applied as 75 kg P205 ha-1 and 37.5 kg K^O ha-~, respectively. The DSSAT-CENTURY model was able to satisfactorily simulate measured wheat grain yield and grain N concentration at NO, but could not simulate these parameters at N150, or SOC in either N treatment, Model simulation and field measurement showed that N application （N150） increased wheat yield compared to no N application （NO）. The results indicated that inorganic fertilizer application at the rates used did not maintain crop yield and SOC levels. It is suggested that if the DSSAT is calibrated carefully, it can be a useful tool for assessing and predicting wheat yield, grain N concentration, and SOC trends under wheat-maize cropping systems.展开更多
文摘A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK＞MNP＞MN＞NPK＞NP＞M＞N＞the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N＞P＞K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.
基金funded by the National Water Special Program of China during 11th Five-Year Plan period(2008ZX07105-002)
文摘This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. The results showed that incomes, residual nitrogen in soil, and the loss of nitrogen in surface water in rice-garlic system were higher than those in rice-fava bean system. There were positive correlations between the nitrogen loss of farmland, nitrogen inputs, residual nitrogen in soil, and incomes of farmland. Economic benefits and environment benefits are both appropriate, if the area of rice-garlic system would be reduced to 53% and the area of rice-fava bean system increased to 36% of total cropping area in the investigated watershed. Adjustment of planting structure and introduction of reasonable rotation systems is considered an effective measure of controlling agricultural non-point pollution in watersheds of Erhai Lake.
文摘pH, exchangeable Ca2+ and Mg2+ of soil can influence the yield and quality of flue-cured tobacco. Xuancheng city is the dominant tobacco-planting region in Anhui province since 2008. A general soil survey was conducted in Xuancheng city to understand the current situations of pH, exchangeable Ca2+ and Mg2+ of farmlands under tobacco-rice rotation and to decide whether continuous applying dolomite powders to abate soil acidification. In total 124 topsoil samples (0-20 cm) were collected from the typical farmlands and soil pH, exchangeable Ca2+ and Mg2+ were measured. The results showed that soil pH and Ca2+ and Mg2+ in Xuancheng city were generally in the suitable grades, pH ranged from 4.56 to 8.42 with an average of 5.87, exchangeable Ca2+ ranged from 1.01 cmol(1/2Ca2+) kg-1 to 100.55 cmol(1/2Ca2+) kg-1 with an average of 11.07 cmol(1/2Ca2+) kg-1, and exchangeable Mg2+ ranged from 0.14 cmol(1/2Mg2+) kg-1 to 2.86 cmol(1/2Mg2+) kg-1 with an average of 0.81 cmol(1/2Mg2+) kg-1, all spanned from the low grades to the high grades. To the whole Xuancheng city, 37.10%, 62.10% and 72.58% of the surveyed farmlands were in the low grades of pH, exchangeable Ca2+ and Mg2+, respectively, while 52.42%, 25.00% and 20.97% of the farmlands were in the suitable grades, respectively. pH had an extremely significantly positive Napierian logarithm correlation with exchangeable Ca2+ and an extremely significantly positive power correlation with exchangeable Mg2+. In total about 338.2 kg·hm-2 of Ca2+ and 202.4 kg·hm-2 of Mg2+ are annually input into the farmlands, while about 110.4 kg·hm-2 of Ca2+ and 7.4 kg·hm-2 of Mg2+ are annually moved out from the farmlands, exchangeable Ca2+ and Mg2+ were annually increased by 225.2 kg·hm-2 and 187.6 kg·hm-2 in the farmlands, respectively. It is necessary to monitor the farmlands dynamically in order to decide whether continuous applying dolomite powders which should be dependent upon the specific conditions of individual farmlands.
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest,China(201003014-6)the National Natural Science Foundation of China(31160413)~~
文摘[Objective] Nitrogen and phosphorus losses of surface runoff in various crop rotation systems in the north of Erhai Lake basin were studied with the objective to provide references for risk evaluation of environmental pollution and formulating countermeasures to control the nonpoint source pollution from agriculture.[Method] Water samples collected in four typical crop rotation systems distributed in seven towns（townships） in the north of Erhai Lake basin were investigated,as well as the fertilizer input,to explore the dynamic change of nitrogen and phosphorus content in surface water of farmland and ditch water,and the correlation between fertilizer input and the concentrations of nitrogen and phosphorus in the surface water of farmland and in the ditch water.[Result] The results showed that nitrogen loss in surface water of farmland in different crop rotation systems differed greatly,and the risk of nitrogen loss was 38% lower in broad bean-rice crop rotation than that in garlic-rice crop rotation.The water soluble nitrogen was the primary form of nitrogen loss.The content of water soluble nitrogen was significantly higher in garlic-rice crop rotation than that in the other rotation systems,and the concentrations of nitrogen in the surface water of farmland in different crop rotation systems followed the sequence below：garlic-rice crop rotationryegrass-rice crop rotationbroad bean-rice crop rotationrape-rice crop rotation.The loss of phosphorus in the surface water of farmland was relatively low and phosphorus combined with silt was the primary form for phosphorus loss.There was no significant difference of the loss of various forms of phosphorus in different crop rotation systems.The contents of total nitrogen and total phosphorus in the surface water of farmland were higher than that in ditch water,with increasing rates of total nitrogen and total phosphorus in ditch water of 72% and 82%,respectively.Topdressing was the critical reason for the high concentrations of nitrogen and phosphorus in the surface water,which also caused the increasing load to the ditch water.[Conclusion] Both the nitrogen and phosphorus loss were the highest in garlic-rice crop rotation.Reasonable crop rotation systems should be established based on both the environmental and economic benefits.This study provided references for controlling the nonpoint source pollution of farmland and improving the water quality of Erhai Lake.
基金funded by the National Natural Science Foundation of China (41471285)the Agricultural Science and Technology Innovation Program (ASTIP) of Chinese Academy of Agricultural Sciences (CAAS-ASTIP-2016AII)+2 种基金the Key Laboratory of Nonpoint Source Pollution Control,Ministry of Agriculture,China (2014-37)the Newton Fund,United Kingdom (BB/N013484/1)the National Key Research and Development Program of China (2016YFD0200601)
文摘Crop modelling can facilitate researchers＇ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 （DSSAT） model together with the CENTURT soil model were employed to investigate the effect of low nitrogen （N） input on wheat （Triticum aestivum L.） yield, grain N concentration and soil organic carbon （SOC） in a long-term experiment （19 years） under a wheat-maize （Zea mays L.） rotation at Changping, Beijing, China. There were two treatments including NO （no N application） and N150 （150 kg N ha-1） before wheat and maize planting, with phosphorus （P） and potassium （K） basal fertilizers applied as 75 kg P205 ha-1 and 37.5 kg K^O ha-~, respectively. The DSSAT-CENTURY model was able to satisfactorily simulate measured wheat grain yield and grain N concentration at NO, but could not simulate these parameters at N150, or SOC in either N treatment, Model simulation and field measurement showed that N application （N150） increased wheat yield compared to no N application （NO）. The results indicated that inorganic fertilizer application at the rates used did not maintain crop yield and SOC levels. It is suggested that if the DSSAT is calibrated carefully, it can be a useful tool for assessing and predicting wheat yield, grain N concentration, and SOC trends under wheat-maize cropping systems.
