再生水灌溉对玉米根际土壤特性和微生物的影响

本研究采用盆栽试验方法,以清水灌溉为对照,分析了不同水质再生水在不同灌溉模式下对玉米根际土壤特性的影响.结果表明,在土壤理化性质方面,再生水灌溉情况下,玉米土壤pH值和电导率(EC)与对照均无显著差异,但pH、EC与灌溉用水pH、EC呈正相关.在土壤营养方面,与对照相比,后期灌三级再生水情况下有效磷、全钾和全氮含量、前期灌二级再生水情况下有效磷和有机质含量均显著增高,这与玉米收获期鲜重和于重测定结果一致,说明前期灌二级再生水和后期灌三级再生水均抑制了根系对养分的吸收,导致玉米生物量下降.在土壤微生物方面,再生水灌溉不同程度地促进了土壤微生物数量的增加;与前期灌二级再生水相比,后期灌二级再生水促进了土壤微生物生长.

The Effect of Irrigation with Reclaimed Water on Soil Peculiarity and Microoaganism Quantity of Maize Root Zone

Irrigation with reclaimed water is an important way to deal with water shortage of agricultural production and solve the problem of sewage pollution. At present, many studies on irrigation with reclaimed water are carried on, and the effect on soil is an important aspect. Taking fresh water irrigation as the control, a pot experiment was used to study the soil characteristic of maize root zone under different irrigation modes with different reclaimed water. The results indicated that, the influence of irrigation with reclaimed water on soil pH and EC was not obvious, but the pH and EC of rhizosphere soil positively correlated with the quality of irrigation water. The content of effective P, total K and total N in the soil irrigated with the third grade water in later growth period of maize increased than that in the control. The content of effective P and organic matter in the soil irrigated with the second grade water in early growth stage of maize also increased significantly, especially the content of effective P being 4-5 times that in the control, which accorded with the fresh weight and dry weight of maize at harvest time, suggesting that the ability of maize to absorb nutrient was restrained under the two irrigation treatments, resulting in the decrease of maize biomass. Irrigation with reclaimed water accelerated the growth of soil microbes. Compared with the irrigation in the early stage, irrigation with the second grade water in later period increased the number of soil microbes.