施肥方式对土壤水肥分布特征影响

The Effect of the Fertilize Methods on Water and Fertilizer Distribution

通过室内土柱试验研究,分析了灌溉施肥与不同深度的土壤施肥处理对土壤水力特性及水肥分布的影响。结果表明,土壤施肥处理不同程度地降低了土壤入渗性能,且施肥层越浅对土壤的减渗作用越大。各处理的土壤水分经过24h再分布过程后无显著差异。在灌溉施肥条件下,土壤中的硝态氮分布较均匀,而磷和钾滞留在土壤表层。对于土壤施肥情况,在灌溉结束后硝态氮被淋洗到湿润峰以上10cm附近,P和K的浓度峰值发生在施肥层附近。施肥深度决定了灌溉结束后浓度峰值出现的位置,施肥层越深,养分浓度的峰值出现的位置越深。

The experiments were caught out to study the effect of fertigation and deep-placement fertilize on soil hydraulic properties and water and fertilizer distribution. The results showed that the fertilizer placement in soil will to some extent reduce the infiltration rate of soil. The lower the fertilizer-applied depth is,the larger the effect on infiltration is. The water distribution in soil at 24 hours after irrigation stopped showed no significant differences among experimental treatments. Under fertigation,the NO3-N in soil is uniformly distributed while P and K is hold up at the surface of the soil. As for the application of fertilizer mixed with soil,the NO3-N is leached out at the positions of 10 cm above the wet front while the concentration peak of P and K occurred near the fertilizer-applied position. The depth of fertilizer-application played positive effect on the depth of the concentration peak.