Abstract:

【Objective】 The objective of the experiment was to investigate the effect of water quantity and quality on soil water-salt dynamic and water consumption of spring-maize. 【Method】 Field experiments were conducted in 2007-2008 in the middle reach of the Shiyanghe River Basin with different irrigation water quantities and salt concentrations. 【Result】 Results indicated that the effect of water quantity on soil water content was obvious in 60-100 cm soil layer. For salt concentration of 9 g?L-1 and 6 g?L-1 treatments, average soil water content of 20-100 cm kept higher than 25% in 2008. Total salt content increased with the increase of irrigation water concentration and decreased with the decrease of irrigation amount. Water deficit in a certain extent could also elevate water use efficiency（WUE） when irrigated with saline water, but WUE will be significantly reduced when increasing salt concentration in irrigation water when soil salinity exceeded a certain level. Yield of spring maize was reduced by 19.4%-57.9% under irrigation with saline water. Yield in treatment of irrigation with water of 9 g?L-1 of salt for two successive years was only 42% of that with fresh water. 【Conclusion】 Reduced irrigation amount reasonably was benefitial to increase WUE and decrease salt accumulation. Saline water which the salt conlent not exceeds 3 g?L-1 can be taken into account for supporting irrigation resource.

Key words: soil water dynamics, salt distribution, yield, evapotranspiration, water use efficiency