Physiological And Ecological Indexes Of Cotton Under Different Irrigation Economic Benefits Research

Developing agricultural water saving and improving the efficiency of water use is an important guarantee for the sustainable development of agriculture in Xinjiang.The application and research of water saving technology is playing an important role in modern agriculture.However,low efficiency of cotton irrigation and water resources waste exsist as a common phenomenon.How to choose the most reasonable and economical irrigation method is the best way to solve the problem.In this study,through selecting three percentages of field water holding capacity(50%~55%),(60% ~65%),(70%~75%)and three irrigation methods of mulched drip irrigation,mulched infiltration irrigation and surface irrigation to analyze the microclimatic environment,soil water content change,salinity change,leaf temperature difference,economic benefit evaluation,and then filter out the most benefits cotton irrigation methods,which could provide some theoretical basis for the efficiency promote of agricultural water.The main conclusions of this paper are as follows:(1)The temperature of surface irrigation was the lowest in different treatments as well as the smaller temperature difference between mulched drip irrigation and mulched infiltration irrigation.The three irrigation methods of temperature difference is big which under the 20 cm depth but smaller when in 200 cm.The mulched drip irrigation and mulched infiltration irrigation of temperature appers lower when the depth in 200 cm than 20 cm,but the surface irrigation presents the opposite distribution law.The mulched infiltration irrigation temperature at 20 cm depth was the highest and the surface irrigation temperature at 20 cm depth was the lowest.(2)The soil water content decreased with the irrigation time.In the same layer of soil,the surface irrigation of soil water contented was the smallest and the mulched infiltration irrigation of soil water content was the largest.With the increase of irrigation amount,the water content in different depth of soil layer decreased gradually.The depth of the same irrigation method,the smaller the degree of water change,the greater change of the surface irrigation in different irrigation methods.(3)The mulched drip irrigation and mulched infiltration irrigation have a good effect on restrain salt content,salt are gathered in the surface of the following 30 cm to 50 cm,the surface irrigation easy to cause cotton soil secondary salinization,salt accumulation in the tillage layer.There was a positive correlation between water content and salt content in the same soil layer.(4)The highest value of leaf temperature appeared in the surface irrigation treatment,the lowest in the mulched infiltration irrigation treatment.The order of cotton leaf temperature from high to low in different irrigation modes were: surface irrigation,mulched drip irrigation and mulched infiltration irrigation.The leaf temperature difference between mulched drip irrigation and mulched infiltration irrigation was smaller,but the surface irrigation was bigger.Both mulched drip irrigation and mulched infiltration irrigation can reduce the temperature of cotton leaf.(5)The root distribution pattern of the surface irrigation presents "umbrella" and the mulched drip irrigation appers "cauda equina".The soil layer depth of mulched drip irrigation was 0~20cm,and the depth of mulched infiltration irrigation layer gathered 10~30cm.(6)The irrigation pattern of mulched drip irrigation and mulched infiltration irrigation were more conducive to the growth of cotton physiology and ecology.The results showed that the yield and economic benefit reach optimum when the field water holding capacity of 60%~65% which under the mulched infiltration irrigation.