| The excessively high nitrogen fertilizer application on farmland and the stagnant crop production are the main problems facing in agricultural production. Therefore, control nitrogenous application, reasonable allocation of other nutrient, synchronous exaltation of crop yield and fertilizer use efficency becomes one of the improtent measures for agricultural sustainable development.Two years rice-wheat rotation (R-W) best nutrient management experiment from 2008 to 2010 were taken in two differents soil fertility experimental sites Baimao and Xinzhuang which were the middle and high fertility soil respectively in Jiangsu Province Suzhou Changshu. Filed experiments were employed with four treatments in 2008 and six in 2009. In order to determine the best nutrient management test scheme of rice-wheat rotation system in Tai Lake basin. The results obstained here could provide theoretical basis for paddy rice and wheat's high yield, high quality and highly effective production in Tai Lake basin.1. Best nutrient management practice could maintain and even enhance the paddy rice and wheat yield by reducing 17.6～48.6% of the farmers practice nitrogen fertilizer application, and significantly increased fertilizer-nitrogen use efficiency.Nitrogen fertilizer application in high fertility soil at Tai Lake basin was 180 kg·hm-2, in middle fertility soil was 210 kg·hm-2, could obtain the higher rice yield which was 9598 kg·hm-2 and 9141 kg·hm-2 respectively, increase yiled 0.4% and 12.8% compared to the lacal farmer's fertilizer practice treatment (FFP). Agronomic efficiency (AEN), Recovery efficiency (REN) and Partial factor productivity (PFPN) were 10.2 kg·kg-1,28.5% and 53.5 kg·kg-1 respectively for Xinzhuang high efficiency treatment (HE), while for Baimao high efficiency treatment 2 (HYHE2), AEN, REN and PFPN were 12.1 kg·kg-1,31.5%,43.5 kg·kg-1. The highest increased range of AEN compared to FFP in high and middle fertility soil was 45.7% and 98.4% respectively.In order to realizes the wheat high production and high nitrogen use effective, N-fertilizer application was 180～210 kg·hm-2 (HYHE treatment) in middle and high fertility soil, wheat yield could achive above 6000 kg·hm-2, N use efficiency was 14.5-22.3 kg·kg-1 and 17.7～·24.6 kg·kg-1 respectively, yield increasing compared to FFP was 23.6% in Baimao and 5.0% in Xinzhuang, while AEN increased 40.3%～74.7% and 6.2%～39.0% for Baimao and Xinzhuang respectively.2. Soil fertility could remarkable influence paddy rice basic yield. Rice basic yield in high fertility soil could reach 7803 kg·hm-2, rice yield in middle fertility soil was 6375 kg·hm-2 in 2008 and 6590 kg·hm-2 in 2009. Yield of CK treatment in two experiment sites was higher than national average level (6300 kg·hm-2). Paddy yield could obviously increase after applying fertilizer, but the scope was only 22.9%～39.7%.For wheat season, wheat yield of control without N-fertilizer treatment (CK) in Xinzhuang was only 1412 kg·hm-2 in 2009 which reduced 765 kg·hm-2 compared to Baimao. The scop of wheat increasing in yield was 97%～319% by adopting the suitable nitrogen application and management measure. Compared with the local FFP treatment, wheat yield increasing 9.3%～26.3% in Baimao by best nutrient management practice, that was only 3.3%～5.0% in Xinzhuang.3. On the Tai Lake middle and high fertility soil, the farmland productivity was the biggest contribution of paddy rice yield (the ratio was above 70%), moreover the contribution ratio of primary nutrient was higher than that of advanced nutrient; the contribution of wheat output was mainly the primary nutrient, for Baimao and Xinzhuang, the ratio were 47.5% and 71.8% respectively, the contribution ratio of advanced nutrient in middle fertility soil was higher than in high fertility soil.4. Wheat plant N accumulation increases quickly from jointing to full heading stage, and the ratio was 30.6%-46.3%, postponing N application formula could sufficient content the wheat later growth stage to the nitrogen demand, meanwhile facilitation the enhanced N-uptake and utilization of wheat plant in grain fulling stage, and increase the wheat output.5. Best nutrient management practice synthesis high-yield cultivation management theory, was beneficial to improve and enhance rice and wheat plant growth status. Both middle and high fertility soil, rice shoot dry weight exhibited an improvement in maturity, mitigated wheat biomass descreased from gain filling stage to mature; besides, BNMP was advantageous to maintain leaf area index and high level leaf SPAD value, retarding leaf senescence.6. Best nutrient management practice could maintain soil Nmin in a quite steady level that was not only advantageous in crops growing to the soil nitrogen absorption, but also reduces the crops harvest, in the soil remains the Nmin content.In summary, carries on the best nutrient management experiment in the Tai Lake area by coordinating the crops growth nutrient absorption rule, the dry matter accumulation rule and the soil nutrient supply rule, could maintain the good crops growth condition, and realizes the goal of reducing nitrogen fertilizer input, improving crop yield and nitrogen fertilizer use efficiency. |
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