安徽省园地氮磷径流流失

茶园、桑园和葡萄园在安徽省分布面积较广,果园的施肥量一般较大,但利用率低,很大一部分氮、磷随地表径流流入水体,给水体污染带来严重威胁。研究安徽省园地径流氮磷流失规律,对于控制安徽省农业面源污染具有重要意义。研究采用径流池收集降雨径流的方法测算出安徽省园地在常规施肥条件下,总氮的年径流流失量为1.85～13.70kg/hm2,其中茶园为2.127kg/hm2,桑园为8.380kg/hm2,葡萄园为7.940kg/hm2;总磷的年径流流失量为0.202～1.770kg/hm2,其中茶园为0.261kg/hm2,桑园为0.263kg/hm2,葡萄园为1.148kg/hm2;总氮的径流流失率在0.049%～0.453%之间,总磷的径流流失率在0.046%～0.416%之间;且铵态氮和硝态氮是园地中氮素径流流失的主要形态,约占总氮的58%,大多数园地中磷素主要以可溶磷的形态径流流失,但在桑园中却只有29.77%的磷素以可溶磷的形态流失。

Nitrogen and Phosphorus Runoff from Garden Plots in Anhui Province

The distribution area of tea garden,mulberry field and grapery are broader in Anhui province.High fertilizer application with a low efficiency in garden plots resulted in nitrogen and phosphorus loss into the water through surface runoff,which caused a serious threat for water pollution.Therefore,to research the characteristic of N and P runoff loss from garden plots has important significance to control agricultural non-point source pollution.In this study,three representative garden plots were selected in Anhui province,to monitor and measure quantitatively the N and P runoff losses under the condition of conventional fertilization by building runoff ponds in farmland.The results showed that the annual runoff loss of total nitrogen was 1.85~13.70 kg/hm2 in garden plots under the condition of conventional fertilization,including which was 2.127,8.380,7.940 kg/hm2 in tea garden,mulberry field and grapery,respectively.The annual runoff loss of total phosphorus was 0.202~1.770 kg/hm2,including which was 0.261,0.263,1.148 kg/hm2 in tea garden,mulberry field and grapery,respectively.The runoff loss percentage of nitrogen fertilizer was between 0.049% and 0.453% and phosphorus fertilizer was between 0.046% and 0.416%.Meanwhile,about 58% of nitrogen was present in the form of nitrate nitrogen and ammonium nitrogen,which were the main forms of nitrogen runoff loss from garden plots.Phosphorus runoff loss was mainly in the form of soluble phosphate in most garden plots,but only about 29.77% phosphorus runoff loss in the form of soluble phosphate in mulberry field.