氮磷肥对黑土浅层土壤氮素累积和移动的影响

利用D饱和最优设计研究了氮磷肥对黑土浅层土壤氮素累积和移动的影响,结果表明,氮磷肥对NO-3 -N含量的影响随着土层的加深逐渐减弱,并且施用尿素的NO-3 -N累积大于施用硝铵。在降雨高峰期存在NH+4 -N向下层土壤的移动,其移动时间滞后于NO-3 -N。尿素施入土壤后对NH+4 -N的累积无明显影响,对NO-3 -N的累积有促进作用。而不同用量的NH+4 -N肥的施入则促进了NH+4 -N的移动和累积。因此黑土玉米农田生态系统氮素做追肥时尿素和硝铵相比尿素更易造成地下水的硝酸盐污染。黑土玉米农田生态系统在作物拔节前期向土壤中施入氮素,将造成这一时期NO-3 -N对地下水的短期污染。

The Effect of Nitrogenous and Phosphorus Fertilizers on Cumulation and Movement of Nitrogen in Shallow Layer of Dark Soil

We studied the effect of nitrogenous fertilizer and phosphorus fertilizer on cumulation and movement of nitrogen in shallow layer of black soil by utilizing D-statured optimum design.The results indicated that the NO~-_3-N contents drops off with the increasing of soil depth after nitrogenous fertilizer and phosphorus fertilizer were used and the amounts of the NO~-_3-N cumulation by applying carbamide were much more than it by applying ammonium nitrate. During the fastigium of rainfall, NH~ _4-N moves into the underlay of soil which was posterior to NO~-_3-N. Acyl amine nitrogenous fertilizer had no obvious effect on the cumulation of NH~ _4-N, but it accelerated the cumulation of NO~-_3-N. The different amounts of NH~ _4-N fertilizer stimnlated the cumulation and morement of NH~ _4-N. So when the nitrogenous fertilizer was applied as superadding fertilizer in corn farmland ecosystem of dark soil, by contrast with ammonium nitrate, carbamide was prone to result in nitrate pollution to groundwater. Applying the nitrogenous fertilizer during the prophase of crop jointing would result in short-term NO~-_3-N pollution to the groundwater.