水田冬种多花黑麦草对土壤氮磷环境释放的影响

Effect of winter cropping Italian ryegrass on N and P leakage from soils

研究以"黑麦草-水稻"草田轮作系统为基础,水田冬种多花黑麦草为研究对象,利用实验生态学的方法,通过对土壤地下渗漏水中N、P含量变化的分析,研究稻田冬种黑麦草的N、P动态,把握在种植过程中N、P向环境原位释放的数量、规律和影响因素,有利于更加客观地评价"黑麦草-水稻"草田轮作系统的环境效应。结果表明,在不施肥的冬闲田,仍可发生N素和P素的损失,一个生长周期中随土壤下渗水的损失量平均为NO3--N 115.98kg/hm2,NH4+-N 0.828 0kg/hm2,P 0.028 5kg/hm2。而冬种黑麦草降低了这种损失,其中施复合肥375kg/hm2处理与冬闲处理相比,NO3--N、NH4+-N和P的淋失量分别降低了49.43%,48.59%,24.11%。施肥量750kg/hm2处理的NO3--N和NH4+-N淋失量比冬闲处理分别降低了38.20%和15.57%,但P的淋失量比冬闲处理略高。

Based on the construction of an Italian ryegrass-rice of N and P loss in underground leakage water under different average loss of N and P through leakage water in the growth rotation （IRR） system, the variety and dynamics experimental treatments were investigated. The cycle was 115.98 kg/ha NO3^--N, 0. 828 0 kg/ha NH4^＋-N and 0. 028 5 kg/ha P under the idle field treatment （CK）. Winter cropping of Italian ryegrass reduced the loss of N and P. Winter cropping Italian ryegrass with 375 kg/hm compound fertilizer, resulted in loss reductions of NO3^--N, NH4^＋-N and P of 49.43%, 48.59% and 24.11%, respectively, compared to the CK. Winter cropping Italian ryegrass with 750 kg/ha compound fertilizer, resulted in loss reductions of NO3--N and NH4＋-N of 38.20% and 15.57%, respectively, while the loss of P was slightly greater than that under CK.