%0 Journal Article
%T Quantitative model for nitrogen and phosphorus loss ratios from agriculture in China based on linear regression<br>基于线性回归的农业氮磷流失比定量模型研究
%A CAI Long-yan
%A <br>蔡龙炎
%J 土壤
%D 2010
%I 
%X Based on nationwide 63 data of nitrogen and phosphorus losses from 32 formally-published papers, the nitrogen and phosphorus loss ratios from agriculture in China were analyzed. The results showed a significant decline in N, P loss ratios values (p<0.05, n = 63) since 1990s. The changes in N and P losses from agricultural systems might be closely connected with widespread eutrophication nationwide. By linear regression analysis, we found that there is a good linear relationship between nitrogen and phosphorus loss ratios from agriculture and their impact factors, the regression equation is Y = -12.057 + 0.063X1 + 0.143X2 - 1.257X3 + 4.796 X4 - 11.060X5 (X1 : precipitation, X2: total nitrogen input, X3: total phosphorus input, X4: slope, X5, TN/TP, Y: N/P). However, there are still some defects in the quantitative model. The quantitative model is of important and realistic in strengthening water environment protection.
%K Linear regression
%K N/P
%K Agricultural system
%K Quantitative model
%K Nitrogen and phosphorus losses<br>线性回归
%K N/P
%K 农业系统
%K 定量模型
%K 氮磷流失
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=03F54A49DE00578AA0E5DDF5BC021AA7&cid=1A8B5357F0EF07B8&jid=56F69E970C6E5190CDB409D28DD0E3C6&aid=EEBF2E40FDBFB83A99B2956B8A156D0F&yid=140ECF96957D60B2&vid=ECE8E54D6034F642&iid=E158A972A605785F&sid=E04FC1B5BC47587B&eid=4964C30D71DF45FF&journal_id=0253-9829&journal_name=土壤&referenced_num=0&reference_num=63