有机-无机肥配施对水稻氮素吸收利用率的影响

Effect of Combined Application of Organic and Inorganic Fertilizers on Nitrogen Uptake and Utilization Efficiency by Paddy Rice

有机肥替代部分化肥是实现中国化肥零增长的重要技术途径之一。在等氮量替代条件下,以水稻特优128为供试材料,设置不施氮肥(M0)作为空白对照,25%有机肥氮替代氮化肥(M1)、50%有机肥氮替代氮化肥(M2)、75%有机肥氮替代化肥氮(M3)、100%有机肥氮替代化肥氮(M4)、单施化肥氮(M5)共6个处理,研究有机肥氮替代化肥氮对水稻氮素吸收利用率的影响。结果表明:(1)随着水稻生育期的不断推进,不同施肥处理土壤碱解氮含量均呈逐渐降低趋势,有机肥氮替代化肥氮能明显增加土壤碱解氮含量,以25%有机肥氮替代化肥氮效果最好;(2)25%有机肥氮替代化肥氮不仅水稻产量最高,还能够显著提高水稻的氮素累积量、氮肥农学利用率、水稻氮肥吸收利用率、氮肥生理利用率及水稻偏生产力。因此,在等氮量替代条件下,提高水稻氮素吸收利用效率,25%有机肥氮替代化肥氮是一种相对适宜的比例。

Replacing part of chemical fertilizer with organic fertilizer is one of the important technical ways to achieve zero growth in use of chemical fertilizer in China.Paddy rice cultivar"Teyou 128"was treated with NPK fertilizers with different levels of nitrogen fertilizer replaced by organic fertilizer.Six treatments were arranged with no nitrogen fertilizer(M0)as the blank control,organic fertilizer with25%nitrogen in place of chemical N fertilizer(M1),organic fertilizer with 50%nitrogen in place of chemical N fertilizer(M2),organic fertilizer with 75%nitrogen replacing chemical N fertilizer(M3),organic fertilizer with 100%nitrogen replacing chemical N fertilizer(M4)and only chemical N fertilizer(M5)to analyze their effects on uptake and utilization efficiency of paddy rice.The results showed that with the development of rice growth,the content of alkali-hydrolyzable nitrogen in the paddy soil tended to decrease gradually under different N fertilizer treatments.Substitution of chemical N fertilizer with organic fertilizer at different rates significantly increased the content of alkali-hydrolyzable N in the paddy soil.The treatment with substitution of chemical N fertilizer with 25%N organic fertilizer had the best effect,not only giving highest yield among the treatments but also significantly increasing N accumulation rate,agronomic utilization efficiency of N fertilizer,nitrogen absorption efficiency,physiological utilization efficiency of N fertilizer,and partial productivity of rice.Therefore,under equal nitrogen replacement of chemical N fertilizer with organic fertilizer,substitution of chemical fertilizer with 25%N organic fertilizer is a relatively suitable ratio to improve the efficiency of nitrogen absorption and utilization in paddy rice.