红壤养分退化研究Ⅲ:土壤和植株的养分淋失

Nutrient degradation in red soils Ⅲ:nutrient leaching losses from red soils and plants

在自然情况和在人工条件下 ,红壤渗漏水中磷的浓度很低 ,而NO- 3-N浓度随着氮肥硝化作用的进行快速增加 .钾的浓度介于氮磷之间 .在施用NH+ 4 -N氮肥时 ,渗漏水中未见NH+ 4 -N出现 .植株和植物残体经雨水淋洗的养分是主要是钾 ,但植物残体磷溶出量也较高 .

Under natural and anthropogenic conditions, the concentration of P in the leachates of red soils was very low, whereas the concentration of NO - 3-N increased rapidly with the proceeding of nitrification. The concentration of K was in between. NH + 4-N was not detected in the leaching water when NH + 4-N fertilizer was applied. The main nutrient leached out by rain from plants and plant residuals was K, but P was also considerable.