中国水稻土壤氮素丰缺指标与适宜施氮量

系统总结了中国开展的水稻土壤氮素丰缺指标与适宜施氮量研究。结果表明：水稻土壤氮素丰缺指标不同区域之间差异颇大，以缺氮处理相对产量90%指标为例，土壤碱解氮含量变动于131~ 248 mg/kg 之间；除辽宁、福建、广东和云南4 省外，中国水稻土壤氮素丰缺指标研究存在很多空白区域；水稻土壤缺氮较为普遍，第3~5 级为土壤氮素集中分布的丰缺级别，缺氮处理相对产量大多处在60%~90%；土壤养分丰缺指标研究的试验点数不宜过少，丰缺指标高端和低端采用外推数据需谨慎，并应予以注明；适宜施氮量与土壤氮素丰缺级别线性负相关，与水稻目标产量线性正相关，与氮肥当季利用率线性负相关；当氮肥当季利用率40%、目标产量4.5~15 t/hm2时，土壤氮素丰缺级别第1~7 级的水稻适宜施氮量范围依次为0~0、23~75、45~150、68~225、90~300、113~375、135~450 kg/hm2。

Abundance-deficiency Indices of Soil N and Appropriate Nitrogen Application Rates for Rice in China

In this paper, researches on abundance- deficiency index (ADI) of soil N for rice (SNFR) and appropriate nitrogen fertilizer application rates (ANFAR) conducted in China are systematically summarized. The results show that there are considerable differences of ADI of SNFR in different regions, soil alkaline hydrolysis nitrogen is 131- 248 mg/kg of 90% relative yield of no nitrogen fertilizer treatment. Except 4 provinces of Liaoning, Fujian, Guangdong and Yunnan, researches on ADI of SNFR in China have many blank areas. Soil N deficiency for rice in China is common, and the abundance-deficiency levels of SNFR focus on level 3-5, and the relative yield of no nitrogen fertilizer treatment is between 60%-90%. For research on ADI of soil nutrient, the number of trial sites should not be too limited，and using extrapolating data for the highend and low-end of ADI should be careful and clearly indicated. ANFAR and the abundance-deficiency level of SNFR have a linear negative correlation, ANFAR and the goal yield of rice have a linear positive correlation, and ANFAR and the nitrogen fertilizer use efficiency in current season (NFUEICS) have a linear negative correlation. When the NFUEICS is 40% and the target yield is 4.5- 15 t/hm2, the ANFAR for the SNFR abundance-deficiency level 1-7 from high to low is 0-0, 23-75, 45-150, 68-225, 90-300, 113-375 and 135- 450 kg/hm2, respectively.