添加不同材料对肥料中氮磷在土壤中淋出特性的影响

Leachability of Nitrogen and Phosphate in Soil Receiving Chemical Fertilizers Amended by Different Treatments

采用6种不同类型的材料与化学肥料复合,通过间歇淋溶实验,研究了不同材料对肥料中N、P淋出特性的影响。结果表明,CK处理(施用化学肥料),经过6次淋溶,氮素淋容量占所施氮素的13%左右,硅酸钠对氮素后期淋溶有一定的促进作用,而沸石、胡敏酸、PAM、柠檬酸对氮素淋溶有一定抑制作用,其中以PAM和柠檬酸抑制作用较大,氮素淋溶量只占所施氮素的6.7%左右。氮素累积淋溶量与时间的关系可用指数方程y=aebt来描述。胡敏酸、PAM、柠檬酸对磷素淋溶有促进作用,以柠檬酸的促进作用最强,而其它材料表现出一定的抑制作用;磷素累积淋溶量与时间的关系可以用双常数方程lny=A+Blnt来描述,其中柠檬酸处理使方程的B值最大,反映磷素淋溶量随时间变化增加最快。

Since studying and producing new types of fertilizer with little side effects on environment and ecosystem, is trend of chemical fertilizer development, in this paper, six kinds of different amendments were employed to complex with chemical fertilizer in research on leaching N and P using intermittent leaching experiment at lab scale. During 24 day incubation for six times leaching, it was found that accumulated amounts of leaching N from the chemical fertilizer applied only (CK) accounted for 13 percent of totally applied N. Additionally, the chemical fertilizer amended with zeolite, humic acid, PAM, and citric acid, respectively, inhibited leaching N, accounting for 6.7 to 9.8 percent of the applied N. However, sodium silicate was capable of increasing leaching N in later period of incubation, resulting in higher accumulated amounts of leaching N than other treatments. The relationship between amounts of leaching N and incubation time can be simulated by equation y=aebt. In this equation, a is initial amount of leaching N, b reflects the increasing amounts of leaching N as incubation time varied. Humic acid caused the equation to have a smaller index a, but have a bigger index b. The accumulated amount of leaching P for CK accounted for only 0.51 percent of the applied P. Thus the chemical fertilizer complexed with humic acid, PAM and citric acid, respectively, could accelerate leaching P so that the accumulated amounts of leaching P accounted for from 0.55 to 0.83 percent of the totally applied P. It may be concluded that the accumulated amount of leaching P can be simulated by equation ln y=A+Bln t. as chemical fertilizer complexed with citric acid caused index B to be bigger, which implied that leaching P increased intensively as incubation time varied.