节水灌溉对盐渍土盐分调控与土壤微生物区系的影响

河套灌区是我国大型自流灌区之一,盐渍化是该区土壤主要障碍因素之一。目前,河套灌区葵花田生育期灌溉量约为1 100～1 200 m3hm-2,灌溉用水量偏大和地下水位偏高已成为制约当地灌溉农业可持续发展的主要障碍:一方面,水资源浪费严重;另一方

Effects of water-saving irrigation on soil salt distribution and soil microflora in saline soil

The field experiments of 4 irrigation amounts (675m?/hm2, 900m?/hm2, 1125m?/hm2 and 1350m?/hm2) were conducted in Wuyuan County, Hetao irrigation area to analyze the effects of irrigation on soil water and salt distribution, yield of sunflower and soil microflora. The result shows that appropriate water-saving irrigation does well in regulating water-salt balance, as well as forming a good micro-ecological-environment for the reproduction of microorganism. The best irrigation amount during the whole growth period is 900m?/hm2, which meets the requirements of salt-controlling and water-saving and is favorable for the reproduction of bacteria and actinomyces, with relatively satisfying yield. Comparing to irrigation treatments, the number of bacteria, actinomyces and fungi of saline wasteland without irrigation is lowest separately, however, over-excessive or over-less irrigation amount is unfavorable to the reproduction of microorganism. The analysis of predominant bacteria under different irrigation amounts indicates that Bacillus and Pseudomonas distribute widely in all of the irrigation amounts and the diversity is the richest in 900m?/hm2 irrigation with Rhizobium, Pseudoxanthomonas and Luteimonas exist in addition. The simple correlation analysis of different factors shows that the correction between microorganism factors and irrigation amount is positive and it is significantly negative between microorganism factors and soil salt content.