聚丙烯酰胺减少土壤养分的淋溶损失研究

Effects of Polyacrylamide Application on the Decrease of Soil Fertilizer and Its Mechanism

采用室内人工土柱模拟试验方法,研究了在模拟耕层土壤中施加聚丙烯酰胺(PAM)后,土壤中主要营养元素N、P、K的淋溶损失状况。结果表明,经PAM处理后的土壤淋溶液中NO-3、PO-4和K+浓度均低于对照,其浓度分别较对照平均减少了约45.55%、49.37%和70.24%。PAM处理后,土壤淋溶液中全N、全P、全K的累积含量均低于对照,且随PAM浓度的增加其累积含量呈下降趋势。

The loss of soil fertilizer in soil not only increases the agricultural cost but also pollute the water resources especially in irrigated fields. The effect of polyacrylamide （PAM） on reducing soil nutrient loss was studied by the intermittent leaching experiment. The result showed that when treated by PAM, the concentration of NO3^- ,PO4^3- and K^＋ in soluble liquid decreased strikingly, the average concentration of them decreased by 45.55%,49.37% and 70.24% compared with the control. The accumulative quantities of the total N, P and K in soil soluble liquid were all less than those of the control and decreased further with the increased concentration of PAM. There existed a significant correlation between the accumulated total N, P, K and leaching time, with the correlation coefficients being larger than 0.98. Since PAM bearing an analogy with other macromolecule polymer that had a large molecular constitutional formula, when applied to the soil, PAM made aggregation with soil particles, built an artificial aggregate structure and form a hydrophobic protecting wire net in the soil surface which enhanced the stability of aggregate, which could ab- sorb the fertilizer element and reduced the loss of fertilizer. The effect mechanism of PAM on soil structure and preventing fertilizer losses should be further researched in different types of soils.