Experimental Study On Effect Of Drip Irrigation With Saltwater On The Soil Water And Salt Transport And The Growth And Yield Of Cotton

Xinjiang is a typical irrigation agriculture in arid oasis area, the surface irrigation water is short, the undergroud saltwater is rich, in the situation of serious shortage of water resources, it is an important way to increase irrigation water and solve water resource crisis that combining saltwater irrigation and advanced irrigation technology-drip irrigation, in recent years domestic and foreign scholars had a lot of researches on saltwater irrigation and drip irrigation, but less researches on combining saltwater and drip irrigation, cotton is as the main crops in Xinjiang which is belong to salt-tolerant crops, so this paper is based on cotton and mainly dicussed the effect of drip irrigation with saltwater on soil water and salt transport, growth and yield of cotton from the two parts of irrigation water salinity and alternative irrigation sequence, which will provide theoretical basis for saltwater irrigation and agriculture saving-water, the main conclusions of this paper are as follows:(1) When using saltwater to irrigation soil water and salt distribution feature is same with freshwater irrigation, but soil salinity situation after irrigation is related with irrigation water salinity; soil salinity increases with the increasement of irrigation water salinity, as well as soil moisture, and when alternative irrigation sequence is different the soil moisture and soil salinity in the same depth are highest when using the alternative irrigation sequence of freshwater, saltwater, saltwater, the second is freshwater, saltwater, freshwater, the lowest is freshwater, freshwater, saltwater;(2) When using saltwater to irrigation the water consumption law of cotton under drip irrigation is same with freshwater irrigation, water consumption decreases gradually with the increasement of irrigation water salinity and when alternative irrigation sequence is different the water consumption of cotton is largest when using the alternative irrigation sequence of freshwater, freshwater, saltwater, the second is freshwater, saltwater, freshwater, the least is freshwater, saltwater, saltwater; irrigation in bud, flower and boll stage is more important, otherwsie the yield of cotton will reduce;(3) After the irrigation in the whole growth period, when using freshwater to irrigation the soil in depth of lm is in the state of desalination, when irrigation water salinity is equal or more than 3.0 g/L the soil is in the state of salt accumulation, and the degree of soil salt accumulation is more serious with the increasement of irrigation water salinity; compared with freshwater irrigation all the time, when using alternative irrigation with saltwater and freshwater the soil is in the state of salt accumulation, the degree of soil salt accumulation is the most serious when using the alternative irrigation sequence of freshwater, saltwater, saltwater, the second is freshwater, saltwater, freshwater, the lightest is freshwater, freshwater, saltwater, and when using alternative irrigation sequence of freshwater, freshwater, saltwater the soil is only a little salt accumulation and has a very small effect on the growth of cotton;(4) Compared with freshwater irrigation, when using saltwater to irrigation the increasement of irrigation water salinity has an inhibiting effect on the growth, leaf area and accumulation of dry matter, the yield of seed cotton reduces with it, but compared with freshwater irrigation of 1.2g/L, the yield of cotton is only reduced 10.74% when irrigation water salinity is 3.0g/L; when using alternative irrigation the effect of irrigation on growth and yield of cotton is the most serious when using the alternative irrigation sequence of freshwater, saltwater, saltwater, the second is freshwater, saltwater, freshwater, the lightest is freshwater, freshwater, saltwater, but compared with freshwater irrigation all the time, when using alternative irrigation sequence of freshwater, freshwater, saltwater the yield of cotton is only reduced 4.00%.Finally combining the effect of irrigation water salinity and alternative irrigation sequence on soil water and salt transport, water consumption of cotton, situation of soil salt, growth and yield of cotton, it was initially identified that when the cotton under drip irrigation used saltwater to irrigation directly, the irrigation water salinity was best to control under 3.0 g/L, when using alternative irrigation mode the sequence of freshwater, freshwater, saltwater is better.