田间施肥引起浅层土中氮的蓄积试验分析

田间施肥后,未挥发和被作物吸收的剩余N素易淋失运移,引起在浅层包气带土壤中的蓄积,且又易再释放进入下层土或地下水中形成污染,并主要受气候、土质结构、微生物作用等的影响。认识和掌握上述规律现象,将有助于研究农田施肥引起地下水污染的治理方法。对田间超量施肥灌溉后,作历时近1年的浅层包气带土壤中N的蓄积试验研究,结果显示:短期内土壤中N的显著蓄积主要发生在土层1.5m以浅部位,随时间、深度及入渗水量的变化而波动。这为探索根治由此引起的地下水污染,提供了较好的应用基础和科学依据。

Fertilization and Nitrogen Accumulation in Shallow Soil of the Field

A large amount of nitrogenous fertilizer that is not absorbed by crops or evaporated into the air is easily leached transport and accumulated in the shallow vadose zone. The accumulated nitrogen is released again and leached down into subsoils and groundwater, causing pollution. The process is mainly affected by climate, soil structure and microorganism transformation, etc. Knowledge and mastery of the above rules will contribute to exploration of ways to control groundwater contamination from fertilization. A field experiment was carried out to determine nitrogen accumulation in the shallow vadose zone within a year after excessive N fertilizer was applied and the field was irrigated. The results showed that nitrogen accumulation mainly occurred in the shallow vadose zone,1.5 m thick, varied with time, depth and amount of infiltration water. The findings of the research may serve as scientific basis for exploring ways to control groundwater contamination caused by fertilizer application.