Effects of surface soil mixed with sand on water infiltration and evaporation in laboratory

Employing sand mixed with surface soil is very conventional way in agriculture, it plays a significant role in control soil water infiltration, evaporation as well as inhibition soil salt accumulation in arid region in Xinjiang area. In present research, simulating experiments were conducted to investigate the effects of different sand mixed rate on soil water infiltration and soil evaporation. The soil cylinder incubation treatments were setup including 0 (Control), 25%, 50%, 75% of sand mixing rate, respectively. There were extremely significant power relationships among wetting front distance, accumulated infiltration quantity and infiltration time under different mixing rate of sand treatments. The more sand mixed, the more soil water infiltration capacity observed, i. e., the infiltration capacity order was 75%>50%>25%>0. Moreover, by means of sand mixed with soil exerted obvious positive effects on inhibition of soil evaporation, namely, the more sand mixed, the remarkable less soil water evaporated, especially when sand mixed rate increased above 75%. The relationship between cumulative evaporation and time could be described by the Rose experience formula under different mixing rate of sand, and had closely fitting accuracy during the successive evaporation of 20 days. The soil moisture at deep layers which under sand mixed layer could also be remarkably enhanced by means of soil surface mixed with sand. The more mixing rate of sand, the remarkable higher soil water content obtained.