Study On Improvement Of Acidity Soil With Lead Pollution

In this study, acidity soil with lead pollution was used as experimental material to study the improvement effects of lime (X₁), calcium magnesium phosphate (X₂) and humic acid (X₃) and the improvement effects of their ratio. "311-A" optimum compound design was adopted in this research, The results were showed as follows:1. Lime raise the pH values of soil , lower weak acid dissolvable lead contents in soil, raise carbonic acid lead, oxidisable lead, and residual lead contents in soil. Lime lower the contents of lead in brassica chinensis shoots too. In this study , low levels (Code number: -2—1) lime enhance brassica chinensis yield while high levels (Code number: 2) restrains.2. Calcium magnesium phosphate raise the pH values of soil , lower weak acid dissolvable lead contents and carbonic acidity lead contents in soil, enhance oxidisable lead contents and residual lead contents in soil. Calcium magnesium phosphate also lower the contents of lead in brassica chinensis shoots. In this study, calcium magnesium phosphate enhance brassica chinensis yield .3.Humic acid lower weak acid dissolvable lead contents, carbonic acidity lead contents, and oxidisable lead contents in soil, and enhance residual leadcontents in soil. In this study, humic acid also lower the contents of lead in brassica chinensis shoots and enhance brassica chinensis yield .4.In this study , mutual effects of lime and calcium magnesium phosphate raise the pH values of acidity soil. Mutual effects of lime and humic acid lower weak acid dissolvable lead contents and enhance residual lead contents in soil. Mutual effects of calcium magnesium phosphate and humic acid enhance residual lead contents in soil.5.In this study, The pH values of soil was significantly anticorrelated with weak acid dissolvable lead contents in soil .The contents of lead in brassica chinensis shoots was significantly correlated with weak acid dissolveable lead contents and significantly anticorrelated with residual lead contents in soil, while were not significantly correlated with oxidisable lead and carbinic acidity lead contents in soil. Fresh weight of brassica chinensis was significantly correlated with weak acid dissolvable lead contents in soil.