农田土壤磷素淋溶及其预测

农田土壤磷素淋溶及其预测

第23 卷第12

期

2003 年12 月

生态学报

A CTA ECOLO G ICA S I N

ICA

V o l. 23, N o. 12

D ec. , 2003

农田土壤磷素淋溶及其预测

吕家珑

(西北农林科技大学资源环境学院, 陕西杨凌712100)

摘要: 农田土壤磷的淋溶损失, 不仅造成肥料利用率降低、农业生产成本上升, 还能引起地下和地表水体富营养化。在综合大量中外文献的基础上, 阐述了农田土壤磷素淋溶问题的提出、淋溶对水体富营养化的贡

献、淋溶液中磷素的形态及其比例、影响土壤磷素淋溶的因子、淋溶机理、预测方法, 并对农田土壤磷素淋溶及其预测作了展望。

关键词: 农田土壤; 磷; 淋溶; 预测方法

Phosphorus leach in g from agr icultura l so ils and its pred ic t ion LU J ia2L ong (R esources and E nv ironm ental College, N orthw est S ci2T ech U niversity of A g ricu ltu re and F orestry ,

Y ang ling , S haanx i 712100, China). A cta Ecolog ica S in ica , 2003, 23 (12) : 2689～2701.

Abstract: Pho spho ru s ( P ) is an essen t ia l elem en t fo r p lan t grow th. It also is a key elem en t fo r eu t roph icat io n of w ater bodie s.T he lo ss of P from agricu ltu ral so ils no t on ly leads to a decrease in the u t iliza t io n rat io of fertilizers and an increase in the co st of agricu ltu ral p roduct io n, bu t also gives rise to the eu t r oph icat i o n of su rface w ater and ground w ate r. Eu t r oph icat i o n, cau sed by P en richm en t, first cam e to the fo re in the 1960s, mo st no tab ly in the Great L akes reg io n of the U SA and Canada. In the fo llow ing decade, a ho st of o ther w ater bodies, suffering from varying degrees of pho spho ru s en richm en t, w ere

iden t if ied around the w o rld. T here are tw o w ays fo r pho spho ru s to en ter w ater bodies2po in t sou rce and

non2po in t sou rce. H um an beings did no t pay enough atten t io n to P lo ss from agricu ltu ral land to w ater bodies un t il the 1960s becau se of its lim ited movem en t in so ils. P m ay be lo st from agricu ltu ral land to w ater bodies by several p rocesse s. T hese include ero sio n, su rface runoff and leach ing. It is repo rted that a bou t 35% of the P inpu ts to natu ralw aters now com e from agricu ltu re in the U K, 70% in D enm ark, and 38% in Ge rm any. Since mo st so ils have a very h igh ab so rp t io n capacity fo r P, u sually far exceeding the quan t it ies of P added as m anu res o r fertilizers, it has long been con sidered that leach ing lo sses of P from

so il to w ater are negligib le in m o st case s. T he concen t r at i o n of P requ ired to t r igger eu t r op h icat i o n in fresh w ater is ex t r em ely s m all (as low as 0102～01035 m g P ƒL. T he p rob lem of P leach ing from so il to w ater w as generally no t con sidered i m po rtan t un t il the 1980s. W hen researchers first m easu red P lo sses in drainage w ater in the U K and U SA. It w as repo rted