A tillage method of combining ridge with no-tillage (RNT) was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern, soil water stable aggregate distribution, nut...A tillage method of combining ridge with no-tillage (RNT) was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern, soil water stable aggregate distribution, nutrients stratification and yields of rice and post-rice crops. After flooded paddy field (FPF) was practiced with RNT for a long time, soil profile changed from G to A-P-G, and horizon G was shifted to a deeper position in the profile. Also the proportion of macroaggregate (> 2 mm) increased, whereas the proportion of silt and clay (< 0.053 mm) decreased under RNT, indicating a better soil structure that will prevent erosion. RNT helped to control leaching and significantly improved total N, P, K and organic matter in soil. The highest crop yields were found under RNT system every year, and total crop yields were higher under conventional paddy-upland rotation tillage (CR) than under FPF, except in 2003 and 2006 when serious drought occurred. RNT was proven to be a better tillage method for lowland rice-based cropping system.展开更多
On farm bio-resource recycling has been given greater emphasis with the introduction of conservation agriculture specifically withclimate change scenarios in the mid-hills of the north-west Himalaya region（NWHR）. Un...On farm bio-resource recycling has been given greater emphasis with the introduction of conservation agriculture specifically withclimate change scenarios in the mid-hills of the north-west Himalaya region（NWHR）. Under this changing scenario, elevation, slope aspect and integrated nutrient management（INM） may affect significantly soil quality and crop productivity. A study was conducted during 2009-2010 to 2010-2011 at the Ashti watershed of NWHR in a rainfed condition to examine the influence of elevation, slope aspect and integrated nutrient management（INM） on soil resource and crop productivity. Two years of farm demonstration trials indicated that crop productivity and soil quality is significantly affected by elevation, slope aspect and INM. Results showed that wheat equivalent yield（WEY） of improved technology increased crop productivity by -20%-37% compared to the conventional system. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-17%. North aspect and higher elevation increased crop productivity by 15%-25% compared to south aspect and low elevation（except paddy）. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-15%. Irrespective of slope, elevation and cropping system, the WEY increased by -30% in this region due to INMtechnology. The influence of elevation, slope aspect and INM significantly affected soil resources（SQI） and soil carbon change（SCC）. SCC is significantly correlated with SQI for conventional（R2 = 0.65＊）, INM technology（R2 = 0.81＊） and for both technologies（R2 = 0.73＊）. It is recommended that at higher elevation.（except for paddy soils） with a north facing slope, INM is recommended for higher crop productivity; conservation of soil resources is recommended for the mid hills of NWHR; and single values of SCC are appropriate as a SQI for this region.展开更多
Soluble phosphate fertilizers have been preferably used in plant crop production. The cost of applying conventional water soluble phosphate fertilizer is high in developing countries since their manufacturing requires...Soluble phosphate fertilizers have been preferably used in plant crop production. The cost of applying conventional water soluble phosphate fertilizer is high in developing countries since their manufacturing requires importing high grade rock phosphate （RP）. As a result, the use of indigenously available low-grade RP is gaining importance globally. In this study, experiments were carried out using clayey loamy alkaline soil to evaluate the agronomic efficiency of fine sized low grade RP with inorganic nitrogen fertilizers and it was further compared with that of soluble phosphate fertilizer （di-ammonium phosphate）, Cicer arietinum was the test crops subjected to treatments of absolute control, di-ammonium phosphate and low grade RP with varying concentrations of ammonium sulphate or ammonium nitrate. The experiments were conducted during 2012-2013 in the bid to study the growth rate and the biomass of the crop. Tests were also performed to determine the residual effects of the fertilizers on the crops. The results revealed that the combined use of low grade RP and ammonium sulphate or ammonium nitrate, at 16 kg N/ha, resulted in an agronomic efficiency, in terms of biomass of plants, comparable to that of di-ammonium phosphate and was found to be a more attractive management option for resource-poor farmers.展开更多
Sustainable potassium （K） management at different soil sites requires understanding the relationships between crop productivity and long-term K fertilizations on a regional or national scale. We analyzed responses o...Sustainable potassium （K） management at different soil sites requires understanding the relationships between crop productivity and long-term K fertilizations on a regional or national scale. We analyzed responses of grain yield of wheat （Triticum aestivurn L.） and maize （Zea mays L.）, K efficiency, and partial balance （difference between K input through fertilizer and K output in the aboveground biomass） during 15- （1990-2005） or 18-year （1990-2008） K fertilizations at five distinctive agroecologicai zones across China. Compared to the inorganic nitrogen （N） and phosphorus （P） fertilization, the inorganic NPK fertilization significantly increased grain yields of wheat （21%） and maize （16% 72%） at Qiyang and Changping, where soils have low exchangeable and non-exchangeable K contents, but not at Uriimqi, Yangling and Zhengzhou, where soils have a high exchangeable and non-exchangeable K and/or low N/K ratio in crop plants. Compared to the inorganic NPK fertilization, the inorganic NPK （30% N） and organic manure （70~~ N） fertilization （NPKM） increased grain yields of wheat （14%-40%） and maize （9%-6170） at four sites, but not at Zhengzhou. For a productivity of wheat at 2-5 t ha-1 or maize at 3-6 t ha 1, 13-26 or 9-17 kg K ha 1 were required to produce 1.0 t wheat or maize. The NP fertilization resulted in the lowest negative partial K balance and accumulated 52 kg K ha-1 year-1 less than the NPK fertilization, which accumulated 28 kg ha 1 year-1 less K than the NPKM fertilization. A re-evaluation of the site-specific fertilization effects on N/K ratio in crop plants and soil K accumulation under current NPK and NPKM t＇ertilization is urgently needed to increase both crop yield and K use efficiency at different agroecologicai zones across China.展开更多
基金Project supported by the National Natural Science Foundation of China (No.40501033)the National Key Technologies R&D Program for the 11th Five-Year Plan of China (No.2007BAD87B10)
文摘A tillage method of combining ridge with no-tillage (RNT) was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern, soil water stable aggregate distribution, nutrients stratification and yields of rice and post-rice crops. After flooded paddy field (FPF) was practiced with RNT for a long time, soil profile changed from G to A-P-G, and horizon G was shifted to a deeper position in the profile. Also the proportion of macroaggregate (> 2 mm) increased, whereas the proportion of silt and clay (< 0.053 mm) decreased under RNT, indicating a better soil structure that will prevent erosion. RNT helped to control leaching and significantly improved total N, P, K and organic matter in soil. The highest crop yields were found under RNT system every year, and total crop yields were higher under conventional paddy-upland rotation tillage (CR) than under FPF, except in 2003 and 2006 when serious drought occurred. RNT was proven to be a better tillage method for lowland rice-based cropping system.
文摘On farm bio-resource recycling has been given greater emphasis with the introduction of conservation agriculture specifically withclimate change scenarios in the mid-hills of the north-west Himalaya region（NWHR）. Under this changing scenario, elevation, slope aspect and integrated nutrient management（INM） may affect significantly soil quality and crop productivity. A study was conducted during 2009-2010 to 2010-2011 at the Ashti watershed of NWHR in a rainfed condition to examine the influence of elevation, slope aspect and integrated nutrient management（INM） on soil resource and crop productivity. Two years of farm demonstration trials indicated that crop productivity and soil quality is significantly affected by elevation, slope aspect and INM. Results showed that wheat equivalent yield（WEY） of improved technology increased crop productivity by -20%-37% compared to the conventional system. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-17%. North aspect and higher elevation increased crop productivity by 15%-25% compared to south aspect and low elevation（except paddy）. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-15%. Irrespective of slope, elevation and cropping system, the WEY increased by -30% in this region due to INMtechnology. The influence of elevation, slope aspect and INM significantly affected soil resources（SQI） and soil carbon change（SCC）. SCC is significantly correlated with SQI for conventional（R2 = 0.65＊）, INM technology（R2 = 0.81＊） and for both technologies（R2 = 0.73＊）. It is recommended that at higher elevation.（except for paddy soils） with a north facing slope, INM is recommended for higher crop productivity; conservation of soil resources is recommended for the mid hills of NWHR; and single values of SCC are appropriate as a SQI for this region.
文摘Soluble phosphate fertilizers have been preferably used in plant crop production. The cost of applying conventional water soluble phosphate fertilizer is high in developing countries since their manufacturing requires importing high grade rock phosphate （RP）. As a result, the use of indigenously available low-grade RP is gaining importance globally. In this study, experiments were carried out using clayey loamy alkaline soil to evaluate the agronomic efficiency of fine sized low grade RP with inorganic nitrogen fertilizers and it was further compared with that of soluble phosphate fertilizer （di-ammonium phosphate）, Cicer arietinum was the test crops subjected to treatments of absolute control, di-ammonium phosphate and low grade RP with varying concentrations of ammonium sulphate or ammonium nitrate. The experiments were conducted during 2012-2013 in the bid to study the growth rate and the biomass of the crop. Tests were also performed to determine the residual effects of the fertilizers on the crops. The results revealed that the combined use of low grade RP and ammonium sulphate or ammonium nitrate, at 16 kg N/ha, resulted in an agronomic efficiency, in terms of biomass of plants, comparable to that of di-ammonium phosphate and was found to be a more attractive management option for resource-poor farmers.
基金Supported by the National Basic Research Program (973 program) of China (Nos. 2011CB100501 and 2007CB309108)the National Natural Science Foundation of China (No. 41071200)
文摘Sustainable potassium （K） management at different soil sites requires understanding the relationships between crop productivity and long-term K fertilizations on a regional or national scale. We analyzed responses of grain yield of wheat （Triticum aestivurn L.） and maize （Zea mays L.）, K efficiency, and partial balance （difference between K input through fertilizer and K output in the aboveground biomass） during 15- （1990-2005） or 18-year （1990-2008） K fertilizations at five distinctive agroecologicai zones across China. Compared to the inorganic nitrogen （N） and phosphorus （P） fertilization, the inorganic NPK fertilization significantly increased grain yields of wheat （21%） and maize （16% 72%） at Qiyang and Changping, where soils have low exchangeable and non-exchangeable K contents, but not at Uriimqi, Yangling and Zhengzhou, where soils have a high exchangeable and non-exchangeable K and/or low N/K ratio in crop plants. Compared to the inorganic NPK fertilization, the inorganic NPK （30% N） and organic manure （70~~ N） fertilization （NPKM） increased grain yields of wheat （14%-40%） and maize （9%-6170） at four sites, but not at Zhengzhou. For a productivity of wheat at 2-5 t ha-1 or maize at 3-6 t ha 1, 13-26 or 9-17 kg K ha 1 were required to produce 1.0 t wheat or maize. The NP fertilization resulted in the lowest negative partial K balance and accumulated 52 kg K ha-1 year-1 less than the NPK fertilization, which accumulated 28 kg ha 1 year-1 less K than the NPKM fertilization. A re-evaluation of the site-specific fertilization effects on N/K ratio in crop plants and soil K accumulation under current NPK and NPKM t＇ertilization is urgently needed to increase both crop yield and K use efficiency at different agroecologicai zones across China.
