Abstract:

 In this paper, we have studied the element contents in rain water and soil

leaching water, the output and input flux of farmland tilth and its influencing factors in

the Chengdu economic region The results show that the rain water in the study area

contains a lot of acidic material such as SO2-4, NO-3, etc, and SO2-4>NO-3>Cl- by

concentration The concentrations of Ca2+ and NH+4 are the highest, and NH+4>Ca2+>

K+>Na+>Mg2+ in the rain water The pH of the rain water and the difference between anion

and cation molar concentration are significantly correlated By concentration,

Pb>As>Cd>Se>Hg in the rain water and Pb>As>Se>Cd>Hg in leaching water in different areas; as

a result, the element of Cd, Pb, Se, Hg, etc are accumulated in tilth layer, and As was

carried out from tilth layer into the underground by leaching The Cd flux in the soil from

the rain water is more than that from leaching; the leaching flux of As is 545 to 1316

times higher than the flux from the rain water in some parts of the area The leaching

ratio of tilth elements is related to soil texture and pH value.

Key words:

Key words: rain water; leaching water; fluxes; the Chengdu economic area