温室滴灌配施尿素下土壤微域内pH值的时空分布研究

The pH Value's Space-time Distribution in Soil Little Intra-area for Greenhouse Drip Irrigation with Urea Utilization

在农业生产实际中,温室滴灌并配合施用尿素的做法较为广泛。研究番茄定额施用尿素,试验结果表明,尿素在土壤脲酶的作用下迅速水解转化,生成大量NH4+而造成土壤pH值升高;在48～72h内在一定的土壤微域内形成一个相对较高的pH值区域;同时,土壤pH值经历了低—高—低的变化过程;随着施肥量的增加,其高值出现相对较早而平缓,维持时间较长。

It is an ordinary method that using urea with dripping irrigation in greenhouse production. The paper reported the ration of urea was fertilized tomato. Every experimental plot was planted 8 seedlings, 6 seedlings, 4 seedlings and 2 seedlings, respectively. Per seedling was fertilized urea 0.46 g. The results show that the urea rapidly decomposed by the function of urease. The pH value was raised resulting in a great mount of NH^＋ in the soil solution. After using urea from 2 to 3 days, there is a small region whose pH value is high in the soil. At the same time, the process of low-high-low of pH value in the soil was got through. With the amount of urea increasing, the peak of pH value came out in the earlier, and could maintain longer time than that of the lower amount of using urea.