不同耕作方式与秸秆还田对稻田氮磷养分径流流失的影响

Effects of Different Tillage and Straw Return on Nitrogen and Phosphorus Runoff Loss from Paddy Fields

为明确自然降雨条件下稻田田面水氮磷养分径流流失特征,寻求秸秆还田和耕作方式结合下较为有效的减排农艺措施,通过田间试验研究自然降雨条件下不同耕作方式和秸秆还田对稻田田面水氮磷养分径流流失的影响。结果表明:秸秆还田处理较秸秆不还田处理更能够有效减少稻田氮磷养分径流流失总量;秸秆不还田条件下,翻耕、旋耕、免耕总氮径流流失量分别为6.78,8.50,11.09kg/hm2,总磷流失量分别为0.50,0.63,0.78kg/hm2;秸秆还田条件下,翻耕、旋耕、免耕总氮流失量分别为4.82,6.44,8.87kg/hm2,总磷流失量分别为0.39,0.51,0.70kg/hm2;整个稻季氮素径流流失率以免耕秸秆不还田为最高,达3.70%,翻耕秸秆还田为最低,仅为1.61%,磷素径流流失率也是免耕秸秆不还田最高,翻耕秸秆还田最低,分别为1.31%和0.65%。

In order to explore the characteristics of nitrogen and phosphorus runoff loss from paddy fields under natural rainfall conditions,and find an effective emission reduction agronomy measures which combined straw return with tillage method,the paper studied the effects of different tillage and straw return on nitrogen and phosphorus runoff loss from paddy fields under natural rainfall condition by field experiments.The result showed that straw return could effectively reduce the total amount of the nitrogen and phosphorus runoff losses from paddy fields than no straw return.In the non-straw treatments,the total amount of runoff nitrogen from paddy fields during rice growth period were 6.78,8.05,11.09 kg/hm2,respectively for plough,rotary tillage and non-tillage,and in the straw treatments,they were 4.82,6.44,8.87 kg/hm2 respectively.Meanwhile,the total amount of runoff phosphorus were 0.50,0.63,0.78 kg/hm2 respectively for plough,rotary tillage and non-tillage in the non-straw treatments,and they were 0.39,0.51,0.70 kg/hm2 respectively in the straw treatments.In all treatments,the nitrogen and phosphorus runoff loss rate of no tillage with no straw were the highest with a value of 3.70% and 1.31%,plough with straw were the lowest with a value of 1.61% and 0.65%.