稻草还田模式对稻田土壤速效氮、钾含量及晚稻生长的影响

设计了高桩翻耕抛栽、覆盖免耕抛栽和高桩免耕抛栽3种模式的田间小区试验。结果表明, 不同稻草还田模式对土壤NH₄⁺-N含量影响较大, 对土壤速效钾含量和土壤NO₃^--N含量影响不大; 高桩翻耕模式的土壤NH₄⁺-N、速效钾含量平均值比高桩免耕和覆盖免耕模式分别提高40.8%、7.5%和36.7%、2.0%; 高桩翻耕能促进水稻群体生长, 增加叶片叶绿素含量, 充分利用光能, 增强光合作用; 稻草还田以高桩翻耕模式的增产效果最好, 比高桩免耕、覆盖免耕分别增产5.8%和9.0%。以高桩翻耕稻草还田模式对土壤速效氮、钾含量及晚稻产量的影响最好。

Effect of Patterns of Straw Returning to Field on Contents of Available N, K in Soil and the Later Rice Growth

The contents of available N, K in the different growth stages of later-rice under different patterns of straw returning to field (SRF) were tested respectively in the experiment. The results indicated that the patterns of SRF siginificantly influenced the contents of NH₄⁺-N in soil and unconspicuously influenced the available K contents of soil and NO₃^--N content of soil. The content of available NH₄⁺-N under conventional tillage with high stubble (CTHS) was 40.8% and 36.7% higher than that under zero tillage with high stubble (ZTHS) and that under zero tillage with covering straw (ZTC), respectively. The available K content of soil under CTHS was 7.5% and 2.0% higher than that under ZTHS and that under ZTC, respectively. CTHS could improve rice growth, increase the content of chlorophyll, make full use of light energy, and enhance photosynthetic rate. The yield of CTHS was 5.8% and 9.0% higher than that of ZTHS and that of ZTC, respectively. So in conclusion, CTHS is the optimal pattern for local area.