This work systematically investigates the effects of wheat straw/corn stalk mulch on the ecological environment in upland crops (winter wheat, summer corn) field from 1997 to 1998. With and without mulch soil moisture distribution, water demand, day and night variation of soil temperature, weeds control, crop yields, water and soil conservation, as well as improvement of soil texture were experimentally investigated. The optimal mulch rate for both water saving and yield increase was determined. Ineffective interplant evaporation can be turned into effective transpiration of leaf by application of wheat straw/corn stalk mulch, which enhances the utility factor of soil moisture and reduces irrigation norm, and may also regulate soil temperature, increase soil fertility, and improve soil texture after being returned to the field. Wheat straw/corn stalk mulch inhibits evaporation of moisture so that accumulation of salinity near the soil surface is prevented, and thus ameliorates salinization of land. In the region of severe soil erosion, mulch is used to cover land so as to forestall hydraulic and wind erosion of the soil. This work systematically investigates the effects of wheat straw / corn stalk mulch on the ecological environment in upland crops (winter wheat, summer corn) field from 1997 to 1998. With and without mulch soil moisture distribution, water demand, day and night variation of soil temperature, weeds control, crop yields, water and soil conservation, as well as improvement of soil texture were experimentally investigated. The optimal mulch rate for both water saving and yield increase was determined. Ineffective interplant evaporation can be turned into effective transpiration of leaf by application of wheat straw / corn stalk mulch, which enhances the utility factor of soil moisture and reduces irrigation norm, and may also regulate soil temperature, increase soil fertility, and improve soil texture after being returned to the field. Wheat straw / corn stalk mulch inhibits evaporation of moisture so that accumulation of salinity near the soil surface is prevented, and thus ameliorates s alinization of land. In the region of severe soil erosion, mulch is used to cover land so as to forestall hydraulic and wind erosion of the soil.