Effect Of Intercropping On Water And Salt Fertilizer And Cotton Growth Characteristics Under Brackish Water Drip Irrigation In Film

In order to investigate the characteristics of water and salt transport under the different water and fertilizer control measures in the intercropping cotton field drip irrigation model,this paper carried out field trials on soil water and salt transport characteristics of halophytes and cash crops in cotton fields under different water and fertilizer control measures.as follows:(1)Different irrigation water quality has a certain effect on soil and crop growth.Brackish water irrigation can improve soil water content.In the early growth stage,fresh water irrigation can reduce irrigation volume and reduce deep seepage.When there is no groundwater recharge,the amount of irrigation should be increased at the later stage of growth so as to ensure the normal growth of cotton.The characteristics of groundwater recharge in different irrigation water quality are the same,and the amount of brackish water treatment recharge is slightly larger than that of fresh water treatment.The change trend of salt content in the soil layer at the growth stage of fresh water treatment and brackish water treatment is basically the same,showing a trend of first increase and then decrease.The effect of fresh water irrigation on salt leaching is better than brackish water irrigation,and brackish water irrigation increases production,but there is a risk of salt accumulation,and brackish water irrigation needs to be supplemented with other measures to prevent salinization.Intercropping with salt plants can increase the average water content in the 0-100 cm soil layer at the growth stage to a certain extent,and the effect between the membranes is more significant.Under the condition of intercropping Suaeda,the greater the amount of irrigation water,the higher the soil moisture content,and the maximum value of the average.(2)Under the conditions of intercropping halophytes,the average water content of 0-100cm soil layer can be increased to some extent,and the effect on intermembrane is more significant.The greater the irrigation volume,the higher the soil moisture content.The difference of moisture content between the membrane is larger than that in the membrane,and the upper layer is larger than the lower layer.Intercropping halophytes increase the water consumption of cotton to a certain extent.Under the condition of intercropping,the greater the amount of water,the greater the soil moisture content,the better one function relationship.Under the treatment of different fertilizations,the difference of the amount of accumulated fertilizer in each treatment is becoming more and more big,and the water content of the soil layer is also more and more different.The soil moisture content was increased significantly.Under the condition of Suaeda salsa,the greater the amount of fertilizer applied,the smaller the water consumption.(3)Intercropping halophytes can obviously reduce the average salt content and desalination rate in the 0-100cm soil layer,and the halophytes has more effect on the interfilm salt content than that in the membrane,and the effect of desalination in the surface layer 0-30cm soil is better than that of the 40-100cm soil layer,and the effect is best.Under the condition of intercropping,the greater the amount of irrigation,the smaller the average salt content in the soil layer at the end of the fertility period,the depth of the soil layer influenced by different irrigation amounts is different.When the irrigation amount is large,the desalination rate of the 0-30cm soil layer is better than that of the 40-100cm soil layer,and the reverse is the opposite when the irrigation amount is small.At the same time,too large or too small amount of fertilizer will cause the increase of soil average salt content,and suitable fertilization can effectively reduce the average soil salinity and reduce the effect of salt on crop growth.(4)Intercropping halophytes can increase the average content of nitrate nitrogen and ammonia nitrogen growth period in soil to some extent,which is beneficial to the growth of cotton and the utilization of nitrogen,and the effect of alfalfa is better than that of the Suaeda.Intercropping halophytes can increase the ratio of potassium to sodium in topsoil,and have the most significant effect at flowering stage.The nitrate nitrogen content in the halophyte treatment group was lower than that of the control group during the period of the growth period,and the halophytes increased the nutrient competition to some extent,that is to say,the amount of fertilizer should be increased in the middle period of the growth period to ensure the normal growth of the crops.The increase of irrigation amount under the condition of Suaeda increased soil nitrate nitrogen to a certain extent,and the average content of ammonia nitrogen growth period was less affected by irrigation amount.In the buds and citigroup with more intensive irrigation,the greater the amount of irrigation,the smaller the ammonia nitrogen content in the soil.The greater the amount of fertilization,the greater the nitrate nitrogen and ammonia nitrogen content in the soil layer.(5)Under the condition of Intercropping of Suaeda,the greater the amount of irrigation,the higher the plant height and the stem diameter,but with the increase of the amount of fertilizer,the plant height and the stem diameter of cotton increased first and then decreased,and the cotton leaf area index was affected most by the amount of fertilizer.Intercropping halophytes can increase cotton yield and water use efficiency.The effect of alfalfa is better than that of alfalfa.Under the condition of intercropping,the greater the amount of fertilizer,the greater the yield and water use efficiency,the greater the irrigation water,the greater the yield,but the increasing and then decreasing of the irrigation efficiency.Under the condition of Suaeda salsa and mung bean,the amount of irrigation and fertilization had a positive effect on the dry matter and yield of cotton.Through regression model calculation,it is found that under the intercropping mode,the comprehensive control measures of water and fertilizer have obvious yield advantages compared with single regulation measures,and the effect is better.The maximum yield of Suaeda salsa was 7303kg/ha,with 5712m/ha and 463kg/ha.The amount of irrigation is 5737m/ha,the amount of fertilization is 303kg/ha,and the maximum yield of intercropping mung bean is 5617kg/ha.Intercropping halophytes can increase the maximum yield of cotton.Intercropping mung beans can reduce the use of chemical fertilizers and reduce costs.