Abstract: The experiment was conducted in natural rainfall condition under in the Danjiangkou reservoir area from 2013 to 2015 to study the characteristics of nitrogen and phosphorus loss from slop farmland and economic benefit under different planting patterns of maize（Zea mays L.） monoculture, maize intercropping angelica dahurica（Angelica dahurica） and maize intercropping sweet potato [Dioscorea esculenta （Lour.） Burkill]. The result showed that the maize and other crops intercropping had better interception effect on nitrogen and phosphorus runoff loss, and could decrease the soil and water runoff loss from slop farmland. In comparison with the maize monoculture, runoff loss of total nitrogen was decreased under maize intercropping angelica dahurica and maize intercropping sweet potato, with the decreases of 32.09% and 20.37%, respectively, the runoff loss of total phosphorus decreased by 32.08% and 18.40%, respectively, and the sediment particle losses decreased by 9.18% and 11.05%. The maize intercropping angelica dahurica had the highest economic benefit, followed by the maize intercropping sweet potato, and the economic net income reached 4.24 times and 2.73 times than maize monoculture, respectively. Maize intercropping angelica dahurica was the optimal cropping pattern and should be adapted to a larger area in Danjiangkou reservoir area according to its economic benefic and non-point source pollution control by nitrogen and phosphorus in farmland.

Key words: maize（Zea mays L.）, intercropping pattern, sloping farmland, control effect, economic benefits, Danjiangkou reservoir area