title: [Minimum application rates for high-yielding rice production system in the Taihu Lake region as a field measure for controlling N and P agricultural loading].
abstract: Excess application with the poor efficiency of fertilizers is one of the major problems confronting the sustainable agricultural development. Whereas, loss of N and P nutrients from farmlands to surface waters is considered as one of the major sources inducing eutrophication. In order to work out a minimum fertilizer application rate for both keeping conventional yield and reducing nutrient loading of non point source pollution, an experiment of formulated fertilization scheme on rice at different rates and nutrient ratios by incorporating the soil supply potential was conducted in a paddy soil Wunitu in Kunshan City, Suzhou. The soil nutrient can supply a yield at 6.75 t/hm2 at least for one cropping season. Among the fertilization treatments, a maximum yield of 9.79 t/hm2 was obtained at fertilization (N + P) rate of 300 kg/hm2kg N and P at a ratio of N to P being 3:2 or 1:1. However, with much lower fertilization (N + P) rate at 240 kg/hm2 with the same ratio a high yield of 9.69 t/hm2 was reached. The fertilizer efficiency of the later was 3 times as that of the former rate. Thus, a economical and environmentally sound mode of fertilization in such paddy soils as total N and P 240 kg/hm2, with N:P:Kratio being 3:2:0 or 1:1:0 was developed. Further study would be directed to a innovation of combination of reducing fertilization rate with rotated fertilization for alternative crops.
authors.affiliation: Inst. Res. Ecos. & Environm. Agri., Nanjing Agric. University, Nanjing 210095, China.
authors.forename: Genxing
authors.initials: G
authors.lastname: Pan
authors.forename: Qinghe
authors.initials: Q
authors.lastname: Zhu
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lianqing
authors.initials: L
authors.lastname: Li
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Huang
authors.forename: Jifang
authors.initials: J
authors.lastname: Wang
authors.forename: Xueyi
authors.initials: X
authors.lastname: Jing
mesh_terms: D018556:Crops, Agricultural / Q000191:economics*; D005308:Fertilizers; D009584:Nitrogen / Q000032:analysis*; D012275:Oryza / Q000254:growth & development*; D010758:Phosphorus / Q000032:analysis*
chemical_list: D005308:Fertilizers; D010758:Phosphorus; D009584:Nitrogen