Study On Cotton Moisture Transfer Model In Salinized Areas Of Southern Xinjiang

At present,soil salinization is one of the major environmental problems faced by China's agriculture.The negative effect of soil salinization is an important factor that restricts the level of agricultural production.Due to special geological and climatic conditions and unreasonable development over the years,The use of water and soil resources has caused serious problems in secondary soil salinization.Therefore,this paper has carried out research on the cotton water migration model in the salinized areas of southern Xinjiang,which is of great significance for improving water resources,especially agricultural water use efficiency,reducing crop costs,and improving the utilization rate of pesticides and fertilizers.The yield of cotton plants in the salinized areas,the improvement of salinized soil,the prevention of secondary salinization of the soil,the conservation of water resources,and the increase in production and income of farmers have made certain contributions.In this paper,three different irrigation treatments(3500 m3·hm-2,4100 m3·hm-2,4700 m3·hm-2)and three different fertilization(nitrogen fertilizer)treatments were set up at two different salt levels(160 kg·hm-2,260 kg·hm-2,360 kg·hm-2),the experiment adopts the method of drip irrigation under the membrane,the phosphate fertilizer is applied as a base fertilizer at one time,and the nitrogen fertilizer is the top dressing in the seedling stage,bud stage and flower of cotton.The bell period and the boll opening period are applied in 4 times.The effects of different irrigation treatments on cotton ecological indexes,water use efficiency and water migration in different salinized soils in southern Xinjiang were systematically studied.The dynamic changes of water in cotton soils were simulated to reveal different cotton field salinization.Soil irrigation production model.Soil moisture content model SHAW model and HYDRUS-2D software to cotton soil moisture numerical simulation method,The main conclusions obtained for the tests and simulations are as follows:The main conclusions of the test and simulation are as follows:1.Generally speaking,cotton seedling emergence of cotton plants in moderately and mildly salinized soils of the cotton field was delayed by 2 to 3 days.If the soil of the cotton field has more salt,the time of emergence of the cotton plant will be pushed back.In moderate salinity soil of cotton field,cotton seedling emergence time of cotton plants treated with high water irrigation and medium water irrigation was 1 to 2 days earlier than that treated with low water irrigation.The results showed that cotton field could dilute the salinity of cotton field soil when the amount of irrigation water was enough,which was more conducive to the emergence of cotton plants at the growth stage.There is a clear distinction between the heights of cotton plants in the cotton field of soils with different salinities.The results showed that under the same amount of fertilizer applied,the height of cotton plants was affected by WH greater than WM greater than WL.As the cotton grows during the growing process,the cotton plant's need for water becomes larger and larger,which makes the height of the cotton plant more distinct when the amount of irrigation water is different.Cotton plants are subject to water stress under the treatment of WL irrigation water.2.On the mild and moderate salinized soils of the cotton field,proper water and fertilizer conservation had no significant effect on the growth and development of cotton plants.Regardless of the mild or moderate salinized soil in the cotton field,the height of the cotton plants treated with other fertilizers was higher than those cotton plants under the treatment of the low irrigation amount of the cotton field(FL WL?FM WL?FH WL).The stem diameter of cotton plant will increase with the promotion of the growth stage of the cotton plant.The stem diameter of cotton plant will grow to a thicker stage from the budding stage to the flaccid stage.In the case of different amounts of water used in the cotton field and the amount of fertilizer applied,the optimal effect on the thickness of the stem of the cotton plant is in the case of water and fertilizer in the case of FMWH.The index of cotton leaf size is greatly influenced by the water content of the cotton field which is more sensitive to the water content of the cotton field.When the amount of irrigation water of cotton field reaches a certain level,the leaves of the cotton plant will increase,grow faster and the index is getting larger.When the irrigation field of the cotton field is not enough,the leaves will become smaller,the amount will become less and fall off,and the size index of the leaves of the cotton plants will also decrease.With the promotion of the growth stage of cotton plants,the size index of cotton leaves decreases in August,and the different amount of irrigation water will have a significant impact on the size index of cotton leaves.3.In the part of the ground of the cotton plant,the formation of the amount of dry matter accumulation is clearly different under different irrigation treatments.When the amount of irrigation water in the cotton field is 4700 m3.hm-2,and the amount of fertilizer applied is 260 kg.hm'-,the maximum is reached.It is concluded that the best irrigation water treatment for the formation of dry matter accumulation in cotton plants is FMWH when the amount of irrigation water in the cotton field is sufficient.Therefore,applying the appropriate amount of irrigation water and the amount of fertilizer applied on the cotton field can better promote the healthy growth of the cotton plant and facilitate the accumulation of dry matter on the ground part of the cotton plant.4.Moisture of cotton plants in saline soils and the fertilizers moved from 0 to 100 centimeters.Under the high irrigation(WH)treatment of the cotton field,the soil moisture content of the cotton field decreased with the increase of fertilizer application.Under FH WH and FM WH treatment,the soil moisture of the cotton field is the maximum at 60 cm.The moisture content of the soil in the cotton field is in the case of FL WH,the main water-bearing area is 20 to 40 cm,and the largest value appears at 40 cm.The soil moisture content of the cotton field decreases with the depth of the cotton field increasing.At 100 cm,the water content of FL WH is higher than that of FH WH and FM WH,and it is easier to cause deep seepage of cotton field soil.At 60 to 80 cm,it is in the same position as the main root system of cotton,which is conducive to the growth of cotton in the case of FM WH.