川东北麦秆还田对水稻氮素吸收转运的影响

摘要

为合理利用秸秆,于2014和2015年两个水稻生长季,在大田条件下,以当地平均施肥量为标准,设置不同量的化肥配施秸秆处理,研究秸秆还田下水稻氮素吸收转运特征.结果表明:较纯化肥处理,秸秆替代一部分氮肥处理对水稻产量、地上部氮素积累量、氮素收获指数及氮肥生产效率无显著影响(P>0.05);在不同程度上降低氮素在穗部的分配比例、营养器官吸收氮素向穗部转运量、转运率、转运氮对籽粒氮素贡献率;在不同程度上提高成熟期营养器官氮素积累量,显著提升抽穗后氮素吸收量及其对籽粒氮素贡献率(P<0.05).综合氮素吸收转运及利用效率,川东北稻麦轮作区水稻季在化肥减施30%基础上,麦秆还田量以6 000 kg/hm2为宜.%Applying agricultural straw residue can improve soil fertility and crop yields.For reasonable utilization of wheat straw,in this study,with local average amount of fertilizer applied as the standard,an experiment about different amount of fertilizer applied with wheat straw residue was conducted to study the N uptake and transformation of rice under field conditions.The results showed that there was no significant effect(P>0.05)when chemical fertilizer combined with wheat straw was applied on rice yield,N accumulation,N harvest index and N production efficiency compared with pure chemical fertilizer.However,the allocation proportion of nitrogen in the ear,the amount of nitrogen translocation from vegetative organs to rice ear,the rate of transfer and the contribution rate of nitrogen translocation to grain were reduced in various degree.While the nitrogen accumulation in vegetative organs was increased in various degree and nitrogen uptake after heading and the contribution rate to grain nitrogen were significantly improved(P<0.05).Considering nitrogen transportation,uptake and utilization efficiency,we suggest that in rice-wheat rotation area in Northeast Sichuan the best amount of straw residue was 6 000 kg/hm2 based on 30% decrement of fertilizer.