粮田改种蔬菜后土壤剖面硝态氮的变化

Changes of nitrate-N accumulated in soil profile after changing grain crop land into vegetables land.

对不同种植方式下0～4m土层硝态氮(NO^-_3-N)累积状况的比较研究表明,粮田改种蔬菜后NO^-_3-N被迅速淋洗到2m以下土层;淋洗到下层的NO^-_3-N累积量随种菜时间的延长而不断增加;蔬菜地约41％～50％的NO^-_3-N累积在2～4m土层,粮田约95％NO^-_3-N累积在0～2m土层,其差异是由于施肥方式、灌水量和作物吸收程度的不同所致。

Soil nitrate-N was rapidly leached below 2 meters after changing grain crop land into vegetable land. Because of the difference in fertilization, irrigation, plant uptake and so on, about 41%-50% of soil nitrate-N was accumulated in the soil horizon with depth of 2-4m in vegetable land, and 95% of that was found in 0-2m layer in grain crop land.