【摘要】 实验研究了北方自然降雨情况下,玉米生育期间的氮素淋溶。结果表明,氮肥的施用量对土壤中硝态氮的积累和移动有影响,氮肥施用量超过300kg hm-2时,0～40cm土层硝态氮累积量明显增加,50cm的土层硝态氮的累积达到高峰;50cm以下土壤中硝态氮累积量逐渐降低,100cm土层施肥处理的硝态氮累积量明显高于对照;从经济效益方面分析,氮肥最佳施肥量为200kg hm-2,过量施肥并不能获得高的经济效益;从环境方面分析,氮肥用量超过150kg hm-2就会发生氮素淋溶。更多还原

【Abstract】 Nitrogen fertilizer is a potential contaminant of the ground water.The purpose of study was to determine influence of fertilizer application rate on the N movement in the soil during crop season.The experiment showed that,the nitrogen rate had influence on the N movement in the soil.While application of fertilizer N over the 300kg hm-2,the nitrate accumulation increased in 0-40cm soil layer,and the accumulation peak was in the 50cm layer.After the 50cm the nitrate was decreased gradually.The soil nitrate accumulation of N treatment was greater than the no nitrogen in the 100cm.The economic nitrogen fertilizer was 200kg hm-2.While the nitrogen fertilizer was over 150kg hm-2 the nitrate leaching will occurr under the spring corn in the dry areas of north China.更多还原