不同基础地力土壤优化施肥对水稻产量和氮肥利用率的影响

【目的】研究江汉平原地区不同基础地力土壤和优化施肥对水稻产量和氮肥利用率的影响。【方法】以江汉平原水稻主推品种丰两优香一号为试验材料，通过3年田间小区试验，考察分析土壤基础地力不同的稻田优化施肥、农民习惯施肥和不施肥处理的产量、氮肥贡献率、土壤氮素依存率和氮肥利用率等的差异。【结果】土壤基础地力不同的稻田均是优化施肥处理的产量最高，与农民习惯施肥处理比较，高地力和低地力稻田优化施肥处理的产量分别平均提高6.9%和5.0%；与不施肥处理比较，产量分别平均提高17.3%和30.3%。与农民习惯施肥处理比较，优化施肥处理的氮肥吸收利用率、农学利用率和偏生产力均大幅度提高。高地力稻田土壤氮素依存率高、氮肥贡献率小、施肥增产的潜力小；低地力稻田土壤氮素依存率低、氮肥贡献率大、施肥增产的潜力大。【结论】优化施肥可以降低水稻产量对土壤基础地力的依赖，提高氮肥利用率。

Effect of Optimized Fertilization on Grain Yield of Rice and Nitrogen Use Efficiency in Paddy Fields with Different Basic Soil Fertilities

【Objective】 The effects of optimized fertilization on grain yield of rice and nitrogen use efficiency in paddy fields with different basic soil fertilities in Jianghan plain of China were studied.【Method】 Three-year field trials were carried out to investigate the differences in grain yield,soil N dependent rate(SNDR),N fertilization contribution rate(NCR) and the N fertilization efficiency of the popular middle rice variety Fengliangyouxiang1 in three treatments,including modified farmers’ fertilizer practice(MFP),farmers’ fertilizer practice(FFP) and the control,in Jianghan plain,China.【Result】 The results showed that the grain yield of MFP was the highest among all the three different nitrogen fertilizer treatments in all the field spots with different basic soil fertilities.The grain yield of MFP increased by about 6.9% and 5.0% in the high soil fertility field(HSF) and low soil fertility field(LSF) compared with the treatment of FFP,respectively;and about 17.3% and 30.3% in HSF and LSF compared with the control,respectively.Moreover,the N recovery efficiency(NRE),N agronomic efficiency(NAE) and partial factor productivity of applied N(PEPN) of MFP increased more greatly compared with that of FFP.The contribution of N fertilization to the grain yield in the LSF was significantly more than that in the HSF;however,low soil N dependent rate and good grain yield potential were observed in the LSF.【Conclusion】 Optimized fertilization reduced the relative contribution of basic soil fertilities to the grain yield of rice and increased N fertilization efficiency.