供氮水平和有机无机配施对夏玉米产量及土壤硝态氮的影响

Effects of nitrogen fertilizer rate and combined application of organic manure and chemical fertilizer on yield in summer maize and on soil NO_3^-—N

通过大田试验研究了不同氮素水平下有机无机肥料配施夏玉米生育期内土壤硝态氮(NO3--N)的变化规律。结果表明,玉米产量主要受施氮量影响,不受有机无机配施影响;土壤的硝态氮含量随施氮量的增加而增加;有机肥与尿素配合施用,可保证土壤长期和短期的氮素的供应;增施有机肥可以协调土壤氮素的供应,降低土壤NO3--N含量,从而可减少对地下水的污染;夏玉米季的施氮安全值在200 kg/hm2较为适宜,且有机肥无机肥配比以3∶1为宜。

Under different nitrogen fertihzer level and with combined application of organic manure and chemical fertilizer, a field experiment was carried out to study the varying characteristics of soil NO3 ^- - N during the growth period of summer maize. The results showad that： summer maize yield was mainly effected by nitrogen fertihzer rate and not effected by the combined application of organic manure and chemical fertilizer; Soil NO3 ^- - N content increased following the rate of nitrogen fertilizer; Combined appli- cation of organic manure and urea could guarantee both long - term and short - term provision of the soil N; Increasing application of organic manure could coordinate the provision of soil N, and reduce the soil NO3 ^- - N content, thus could decrease the pollution to the ground water. Under the condition of our field experiment, secure fertilizing nitrogen amount of summer roaize was within the scope of 200 kg/hm^2, and the organic manure and chemical fertilizer with a ratio at 3 ： 1 was proper.