| Soil salinization,water resources shortage,and low efficiency of water utilization are especially severely in Xinjiang.In order to amend alkali-saline soil and improve the production and quality of cotton,the field experiments of magnetized fresh water and brackish water irrigation treatments,and the plot experiment of magnetized fresh water irrigation treatment in three types of alkali-saline soils were conducted to investigate the effect of magnetized water on soil water-salt distribution and cotton growth characteristics.The main results are as follows:(1)The magnetized water irrigation treatment could improve the water holding capacity and strength the absorption of cotton roots to water,thus increasing soil moislure effectively.The soil water content of magnetized fresh water irrigation treatment was greater than magnetized brackish water irrigation treatment.The water content of three types of alkali-saline soils in order are heavy alkaline soil(high),moderate alkaline soil,mildly alkaline soil.The soil water content and consumption were significantly affected by magnetic field intensity,the water consumption of all magnetization treatments were greater than unmagnetized control treatment in whole cotton growth period,in which the 3000Gs treatment is the most effective.(2)The magnetized water irrigation treatment could decrease the salt salinty of soil-root layer,the soil concentration and salt content of magnetized fresh water and brackish water irrigation treatments were lower than control treatment.Besides,the soil salinity of magnetized fresh water irrigation treatment was lower than magnetized brackish water treatment For alkali-saline soils under magnetization,the soil salinity was less then control treatment.The intensity of magnetic field had great influence on soil salinity,the desalting capacity was the strongest for 3000Gs treatment.(3)The magnetized fresh water and brackish water irrigation treatments had remarkable effect on growth characteristics of cotton,including plant height,stem diameter,leaf area index,chlorophyll content and net photosynthetic rate,which were greater than control treatment.Besides,the cotton growth indicators of magnetized fresh water irrigation treatment were greater than magnetized brackish water treatment.There were negative correlations between cotton growth indicators and salt content of alkali-saline soil,which alkaline degree ranges from light to high.The magnetized water irrigation treatment could promote growth and development of cotton in which 3000Gs is the optimal treatment,with the increase of magnetization intensity,the growth characteristics increased firstly and then decreased.(4)The cotton biomass,yield and water use efficiency of magnetized fresh water and brackish water irrigation treatments were larger than control treatment.Compared with magnetized brackish water treatment,the cotton biomass of magnetized fresh water irrigation treatment was increased by 4.1%?18%,the cotton yield was increased by 1.1%?6%and the water use efficiency was increased by 0.6%?5.1%.The biomass,yield and water use efficiency of cotton showed an increasing tendency from heavy alkaline soil to mild alkaline soil.The above ground biomass and yield of cotton were increased obviously by using magnetic water within an appropriate magnetization intensity,which 3000Gs treatment is the best magnetic treatment by taken into consideration of cotton yield and water use efficiency.Compared with control treatment,the cotton biomass of 3000 Gs treatment in three types of alkali-saline soils were increased by 53%?99.5%,the yield was increased by 28.8%?31.69%and the water use efficiency was increased by 27.4%?42.8%.(5)By using the logistic model to match the changes of cotton plant height,leaf area index and total biomass with growth period,the empirical model that fit for magnetized water of under-film drip irrigation was proposed. |
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