秦王川灌区种植披碱草和小麦对耕地盐碱的影响

Effects of Growing Triticum aestivum and Elymus dahuricus Turcz. on Salinization of Cultivated Landin Qinwangchuan Irrigated Regions

实验以小麦(Triticum aestivum)和披碱草(Elymus dahuricus Turcz.)及其下部土壤为研究对象,通过测定植被的盖度、高度、地上生物量及其下部土壤的水、盐含量等指标,探究了秦王川灌区种植小麦和披碱草对耕地盐碱的影响差异。结果表明:当耕地种植小麦和披碱草后,其地表光照强度、温度和土壤表层(0~5cm)盐含量均显著低于裸地,而地表湿度和土壤表层含水率正好相反,均显著高于裸地(p<0.05)。小麦收获前,种植小麦和披碱草耕地表层盐含量较裸地分别降低近57%和42%;秋末,种植披碱草耕地表层的盐分依然较裸地降低近44%,而原种植小麦地的土壤表层盐含量却较裸地升高了18%。综合以上,秦王川灌区种植春小麦因生育期较短易引发土壤盐碱危害,而种植披碱草可全年覆盖耕地地表,从而可降低耕地发生次生盐渍化的风险。

To explore effects of planting Triticum aestivum and ElymusdahuricusTurcz on salinization of cultivated land in Qinwangchuan irrigated region, Triticum aestivum, ElymusdahuricusTurcz and soil below--groundwere re- garded as research objects in experiment. Analysis of soil moisture and salt was donethrough measuring coverage, height, above--ground biomass of vegetation and moisture and salt content of soil. Results showed that compared with the bare land, the surface sunshine intensity, temperature and salt content of surface soil （0--5cm） under vege- tation coverage showed significant decrease, while ground humidity and soil moisture content were significantly in- ereased（p%0.05）. Before wheat harvest, the topsoil salinity of planting wheat and Elymusdahuricuswere nearly 57~ and 42~/0lower than that of bare land. When autumn came, the surface salt of Elymusdahuricus field is nearly 44~ lower than that of bare ground while the surface salinity of wheat field was nearly 18 ~//0 higher than that of bare land. Obviously, planting spring wheat in Qinwangchuan irrigated regions of Northwest China would cause soil secondary salinization, while planting ElymusdahuricusTurcz may weaken hazard of soil secondary salinization.