盐渍土持续利用过程中土壤有机质演化的阶段特征

以曲周试验区为例研究了盐渍土改良和持续利用过程中，土壤有机质演化的阶段性特征。盐生植被的归还条件下，土壤有机质含量小于0．5％，甚至近乎贫瘠；开垦后，作物生物总产量增加，以根茬归还土壤，土壤有机质可维持在0．8％～0．9％；加大秸秆还田量，土壤有机质可提高并维持在1．0％～1．2％；农牧结合，以优质的有机物质归还土壤，使土壤有机质持续提高至1．5％左右。同时，研究了土壤肥力持续提高的系统培肥措施。

Characteristics of Soil Organic Matter in the Process for Sustainable Use of Aalt-affected Soil in Quzhou Experiment Area

In the process of amelioration for salt affected soil and its sustainable use in the Quzhou experiment area, the phasic characteristics of soil organic matter in the area were studied in this paper. In the condition of revert of the halophyte, the soil organic matter is less than 0. 5 %, the soil is even more poor. For the clearage soils, the crop biomass is increased, if the crop roots is returned to the soils, the organic matter kept 0. 8% ~0. 9%. If the returned straw into the soil is increased, it can be increased the organic matter in the soil to 1. 0% ~ 1. 2%. If the generous organic matter is returned to the soils, the soil organic matter can be risen to 1. 5%. Finally, the authors proposed the systematic measure for improvement of soil fertility.