施肥对土壤硝态氮含量及分布的影响及合理施肥研究

Effcet of Applying Fertilizer on Content and Distribution of NO_3^--N in Chao Soil and Reasonable Fertilzer Application

通过3 a 6季作物收获后测定不同施肥方式下潮土1 m土层中的硝态氮，结果表明无论是0～20 cm、80～100 cm还是0～100 cm土层，其硝态氮含量顺序均是N＞NK＞NP＞NPK＞SNPK＞MNPK；0～20 cm土层中硝态氮相对值随降雨量增大而减小，降水量大则硝态氮向下淋溶较多；施有机肥或秸秆还田有减轻淋溶的作用。0～60 cm土层中硝态氮相对值在测定时期及处理之间差异均不显著。

The content of NO3--N in 0～100 cm Chao soil after harvest with different fertilizer treatment through 3 years were analyzed. The results indicated that the NO3--N content in 0～20 cm, 80～100 cm and 0～100 cm soil layers was decreased in the order: N> NK> NP> NPK> SNPK > MNPK. The NO3--N content in 0～20 cm layer decreased with precipitation, that was to say precipitation could accelerate NO3--N leaching down, but manure and straw could reduce the leaching. The percentage of NO3--N distributed in 0～60 cm soil layer varied little in different fertilizer treatments.