Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilize...Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilizer recommendations for paddy fields. PFRS utilized geographical information system (GIS) ActiveX Controls, enabling the user to select a location of interest linked to a spatial database of paddy field soil characteristics. The application package also incorporated different soil fertilizer recommendation methods, forming a relational database. The application's structure consisted primarily of building database queries using Standard Query Language (SQL) constructed during run-time, based on user provided spatial parameters of a selected location, the type of soil desired and paddy production criteria. PFRS, which was comprised of five modules including: File, View, Edit, Layer and Fertilizer/Model, provided the user with map-based fertilizer recommendations based on selected soil nutrient P and K map layers as well as N characteristics and land use maps.展开更多
The effectiveness of polyolefin-coated urea （Meister-5 and Meister-10; CU） in a wheat （Triticum aestivum L.）-maize （Zea mays L.） rotation system was studied in lysimeter plots located in the North China Plain fo...The effectiveness of polyolefin-coated urea （Meister-5 and Meister-10; CU） in a wheat （Triticum aestivum L.）-maize （Zea mays L.） rotation system was studied in lysimeter plots located in the North China Plain for three consecutive maizewheat-maize cropping seasons. An isotopic method was used to compare the fate of CU to that of non-coated urea （NCU）, and N application rates of 0, 100, 150 and 225 kg N ha-1 were evaluated. The results showed that the nitrogen use efficiency （15NUE） of CU was 13.3%-21.4% greater than that of NCU for the first crop. Alternatively, when the difference method was applied （apparent NUE）, no significant variations were observed among treatments in all three seasons. Although inorganic N leached from the 1.3 m layer was less than 1% of the total applied N, unidentified losses of 15N （losses of 15N = 15N applied as fertilizer - 15N absorbed by crops - 15N remaining in the 0-0.2 m layer - 15N leached from the 1.3 m layer） in CU-treated plots were 24.2%-26.5% lower than those of NCU-treated plots. The nitrate concentration in the 0-1.3 m layer of CU plots at the end of the experiment was 53% lower than that of NCU-treated plots. Thus, CU increased crop N uptake from fertilizer and reduced unidentified losses of applied N, which can reduce the risk of groundwater pollution.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 40001008) the China-British Higher Education Links (No. SHA/992/297).
文摘Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilizer recommendations for paddy fields. PFRS utilized geographical information system (GIS) ActiveX Controls, enabling the user to select a location of interest linked to a spatial database of paddy field soil characteristics. The application package also incorporated different soil fertilizer recommendation methods, forming a relational database. The application's structure consisted primarily of building database queries using Standard Query Language (SQL) constructed during run-time, based on user provided spatial parameters of a selected location, the type of soil desired and paddy production criteria. PFRS, which was comprised of five modules including: File, View, Edit, Layer and Fertilizer/Model, provided the user with map-based fertilizer recommendations based on selected soil nutrient P and K map layers as well as N characteristics and land use maps.
基金Supported by the National Basic Research Program (973 Program) of China (No. 2007CB109302)the Special Fund for Agro-Scientific Research in the Public Interest, China (No. 201103007)the Japan-China Co-operation Project
文摘The effectiveness of polyolefin-coated urea （Meister-5 and Meister-10; CU） in a wheat （Triticum aestivum L.）-maize （Zea mays L.） rotation system was studied in lysimeter plots located in the North China Plain for three consecutive maizewheat-maize cropping seasons. An isotopic method was used to compare the fate of CU to that of non-coated urea （NCU）, and N application rates of 0, 100, 150 and 225 kg N ha-1 were evaluated. The results showed that the nitrogen use efficiency （15NUE） of CU was 13.3%-21.4% greater than that of NCU for the first crop. Alternatively, when the difference method was applied （apparent NUE）, no significant variations were observed among treatments in all three seasons. Although inorganic N leached from the 1.3 m layer was less than 1% of the total applied N, unidentified losses of 15N （losses of 15N = 15N applied as fertilizer - 15N absorbed by crops - 15N remaining in the 0-0.2 m layer - 15N leached from the 1.3 m layer） in CU-treated plots were 24.2%-26.5% lower than those of NCU-treated plots. The nitrate concentration in the 0-1.3 m layer of CU plots at the end of the experiment was 53% lower than that of NCU-treated plots. Thus, CU increased crop N uptake from fertilizer and reduced unidentified losses of applied N, which can reduce the risk of groundwater pollution.
