关键词: 秋浇, 水盐运移, 淋失量, 农田类型, 河套灌区

Abstract: Autumn irrigation is a particular irrigation system designed to wash soil salt into deeper layers and retain a higher water content for the following spring crops in the Hetao Irrigation District of China.The effects of autumn irrigation on leaching of soil salt in different types of farmland in the Hetao Irrigation District are discussed on the basis of field determination of amounts of soil salt leached in 5 types of farmland.Before irrigation,the soil moisture content was the highest in the cabbage field and the lowest in the sunflower field. Autumn irrigation increased soil moisture in all the fields,showing no significant difference between them.After the autumn irrigation,the leaching of soil salt from the soil profiles was in a decreasing order of surface layer(0-40 cm),middle layer(40-80 cm)and deep layer(80-120 cm)in all the fields except the sunflower field,and in a decreasing order of cabbage field,sunflower field,maize field,spring wheat maize inter planting field and spring wheat field.It can be concluded that the leaching of soil salt during the autumn irrigation in fields without crops is significantly correlated with the increase in soil moisture content in 0-100 cm( r =0.990 2),but not with the content of salt in the soil before irrigation.

Key words: autumn irrigation, water and salt transport, leaching amount, farmlands, Hetao Irrigation District