In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of ...In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.展开更多
The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the...The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch (Mv). We conducted a 10-year (2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application (22.5 Mg ha^–1). Fertilizer and Mv were applied both individually and in combination (sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80 (by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index (SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input (22.5 Mg ha^–1), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate (with the value higher by 71.6 and 70.1%), whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers (e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China.展开更多
A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon(C) and total nitrogen(TN) under ploughing back o...A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon(C) and total nitrogen(TN) under ploughing back of Chinese milk vetch for 5consecutive years.Six treatments were included in the experiment,they are CK(unfertilized),CF(100% chemical fertilizer with the amount of N,P2O5,K2 O being150,75,120 kg/hm^2respectively),A1(22 500 kg/hm^2 Chinese milk vetch and 100%chemical fertilizer),A2(Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A3(Chinese milk vetch and 60% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A4(Chinese milk vetch and 40% nitrogen and potassium fertilizer and 100% phosphate fertilizer).The results were as follows:application of fertilizer could increase the yield of rice,while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield.Under the condition of milk vetch application with 22 500 kg/hm^2,the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF.And the yield of treatment A3 was basically identical to or slight increase in comparison with that of CF.Decreasing amount of fertilizers cloud improve output value of rice in the case of the utilization of Chinese milk vetch.The treatment A1 increased output value of rice by 5.92% in comparison of CF,and treatment A2 was by 4.08% in the next.Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only.There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF.In general,amount of application of milk vetch with 22 500 kg/hm^2 could replace chemical fertilizer partially,it also could improve rice yield,decrease the production cost,and raise the utilization efficiency of nutrients.展开更多
Green manure can be used as a substitute for chemical fertilizer without reducing rice yield.We studied the responses of soil fertility and rice yield to different combinations of Chinese milk vetch(CMV;Astragalus sin...Green manure can be used as a substitute for chemical fertilizer without reducing rice yield.We studied the responses of soil fertility and rice yield to different combinations of Chinese milk vetch(CMV;Astragalus sinicus L.)and chemical fertilizer in a subtropical double-rice cropping system.Our goal is to reduce chemical fertilizer use and decrease environmental contamination.Compared with the recommended rate of chemical fertilizer(CF),both early-and late-rice yields in the two treatments supplied with 15 and 22.5 Mg CMV ha^-1 plus 60%CF(represented as 60 A and 60 B,respectively)showed no significant differences while the two treatments supplied with 30 and 37.5 Mg CMV ha^-1 plus 60%CF(represented as 60 C and 60 D,respectively)showed significantly higher values.The sustainable yield index(SYI)values in the 60 C and 60 D treatments with double-rice croppong system were significantly higher than those in other treatments(P<0.05).Early-rice yield showed a significant positive relationship with the Chinese milk vetch incorporation rate.The coefficients increased annually from 2009 to 2013 and then decreased in 2014.Soil organic matter increased over time by the end of the experiment in all of the treatment groups.Soil organic matter in 60 A,60 B and 60 C showed no significant difference compared with that in CF,while soil organic matter in 60 D was significantly higher than that in CF.The slopes of soil organic matter and total nitrogen over six years were the highest in 60 C and 60 D.The soil total nitrogen content in 60 A,60 B,60 C and 60 D was higher than that in CF,but the differences were not significant(P>0.05).Therefore,a relatively high Chinese milk vetch incorporation rate(≥30 Mg ha^-1)was more effective in improving the productivity and sustainability of paddy soil.The decreased coefficients of early-rice yield and the Chinese milk vetch incorporation rate in 2014 implied that the benefits of soil fertility and rice yield created by Chinese milk vetch input may decline after five years under a continuously high rate of Chinese milk vetch incorporation.展开更多
文摘In order to explore the technology and effects of reducing nitrogen and potassium fertilizer applications in double-cropping rice,a field plot experiment was conducted to study the effects of optimized application of nitrogen and potassium fertilizers combined with returning Chinese milk vetch and straw to fields on yield,fertilizer utilization efficiency,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO_(2) concentration(Ci),chlorophyll content(SPAD value)and soil physical and chemical properties in late rice harvest period.The results showed that the optimized application of nitrogen and potassium fertilizers combined with the integrated technology of Chinese milk vetch and straw co-returning to the field could enhance the photosynthetic efficiency of double-cropping rice,increase rice yield,and enhance soil biological activity,especially T4 treatment involving the returning of Chinese milk vetch and straw to the field instead of 30%nitrogen fertilizer achieved the highest rice yield,fertilizer use efficiency,net photosynthetic rate and soil biological activity.Compared with the conventional fertilization treatment T2,the total rice yield of T4 treatment increased by 4.1%,among which the early rice and late rice increased by 6.3%and 2.4%,respectively;Pn,Gs and SPAD values of flag leaves at full heading stage significantly increased,and the contents of soil active organic carbon,alkali hydrolyzed nitrogen,available phosphorus and readily available potassium significantly increased.
基金supported by the earmarked fund for China Agriculture Research System (CARS-22)the Key Special Projects in National Key Research and Development Plan of China (2017YFD0301504 and 2016YFD0300900)+1 种基金the Scientific and Technological Innovation Project in Hunan Academy of Agricultural Sciences, China (2017JC47)the International Plant Nutrition Institute, Canada (IPNI China Program: Hunan-18)
文摘The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch (Mv). We conducted a 10-year (2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application (22.5 Mg ha^–1). Fertilizer and Mv were applied both individually and in combination (sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80 (by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index (SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input (22.5 Mg ha^–1), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate (with the value higher by 71.6 and 70.1%), whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers (e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201103005-08)National Science and Technology Support Program during the 12thFive-year Plan(2012BAD05B05-3)International Plant Nutrition Institute S&T Program(Hunan-16)~~
文摘A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon(C) and total nitrogen(TN) under ploughing back of Chinese milk vetch for 5consecutive years.Six treatments were included in the experiment,they are CK(unfertilized),CF(100% chemical fertilizer with the amount of N,P2O5,K2 O being150,75,120 kg/hm^2respectively),A1(22 500 kg/hm^2 Chinese milk vetch and 100%chemical fertilizer),A2(Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A3(Chinese milk vetch and 60% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A4(Chinese milk vetch and 40% nitrogen and potassium fertilizer and 100% phosphate fertilizer).The results were as follows:application of fertilizer could increase the yield of rice,while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield.Under the condition of milk vetch application with 22 500 kg/hm^2,the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF.And the yield of treatment A3 was basically identical to or slight increase in comparison with that of CF.Decreasing amount of fertilizers cloud improve output value of rice in the case of the utilization of Chinese milk vetch.The treatment A1 increased output value of rice by 5.92% in comparison of CF,and treatment A2 was by 4.08% in the next.Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only.There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF.In general,amount of application of milk vetch with 22 500 kg/hm^2 could replace chemical fertilizer partially,it also could improve rice yield,decrease the production cost,and raise the utilization efficiency of nutrients.
基金funded by the National Key Research and Development Program of China(2016YFD0800500 and 2016YFD0200800)the National Natural Science Foundation of China(31860592)+2 种基金the earmarked fund for China Agriculture Research System(CARS-22-Z-06)the Special Scientific Research Fund of Agricultural Public Welfare Profession of China(201503123-07)the Innovation Fund of Jiangxi Academy of Agricultural Sciences,China(2015CBS007 and 20182CBS002)。
文摘Green manure can be used as a substitute for chemical fertilizer without reducing rice yield.We studied the responses of soil fertility and rice yield to different combinations of Chinese milk vetch(CMV;Astragalus sinicus L.)and chemical fertilizer in a subtropical double-rice cropping system.Our goal is to reduce chemical fertilizer use and decrease environmental contamination.Compared with the recommended rate of chemical fertilizer(CF),both early-and late-rice yields in the two treatments supplied with 15 and 22.5 Mg CMV ha^-1 plus 60%CF(represented as 60 A and 60 B,respectively)showed no significant differences while the two treatments supplied with 30 and 37.5 Mg CMV ha^-1 plus 60%CF(represented as 60 C and 60 D,respectively)showed significantly higher values.The sustainable yield index(SYI)values in the 60 C and 60 D treatments with double-rice croppong system were significantly higher than those in other treatments(P<0.05).Early-rice yield showed a significant positive relationship with the Chinese milk vetch incorporation rate.The coefficients increased annually from 2009 to 2013 and then decreased in 2014.Soil organic matter increased over time by the end of the experiment in all of the treatment groups.Soil organic matter in 60 A,60 B and 60 C showed no significant difference compared with that in CF,while soil organic matter in 60 D was significantly higher than that in CF.The slopes of soil organic matter and total nitrogen over six years were the highest in 60 C and 60 D.The soil total nitrogen content in 60 A,60 B,60 C and 60 D was higher than that in CF,but the differences were not significant(P>0.05).Therefore,a relatively high Chinese milk vetch incorporation rate(≥30 Mg ha^-1)was more effective in improving the productivity and sustainability of paddy soil.The decreased coefficients of early-rice yield and the Chinese milk vetch incorporation rate in 2014 implied that the benefits of soil fertility and rice yield created by Chinese milk vetch input may decline after five years under a continuously high rate of Chinese milk vetch incorporation.