【摘要】 在鄂西南烟区研究了化肥不同施用方式对植烟土壤有效氮时空动态的影响。结果表明,在降雨量较大年份,烟叶移栽后一个月内化学肥料带入的有效氮基本全部损失,有机肥料带入的氮素(有机态氮)则在移栽后45～70 d内在0～20 cm土层内发挥作用;移栽后60 d左右土壤自身有机氮开始矿化加速导致土壤有效氮升高。揭膜可以使化学氮素大量淋失,而全生育期覆膜则使后期土壤有效氮升高。提前施肥可能会使无机肥料氮素转化为有机氮,使氮素淋失的风险大幅度降低。更多还原

【Abstract】 A field experiment was carried out in tobacco planting soil in southwest Hubei to study the effect of different fertilization pattern on available nitrogen dynamics.The results showed that,in years of high rainfall,nitrogen from chemical fertilizers completely leached out within one month after tobacco transplanting.Nitrogen from organic fertilizer in 0-20 cm soil supplied nitrogen to tobacco within 45-70 d after transplanting.Soil organic nitrogen started to mineralize,which increased soil available nitrogen contents 60 d after transplanting.Chemical nitrogen largely leached out under uncover condition and soil available nitrogen increased if using plastic cover.Applying nitrogen fertilizer earlier can cause chemical nitrogen to transfer to organic nitrogen,thus reduce the risk of nitrogen leaching greatly.更多还原