Study On Optimal Design Of Drip Irrigation Pipe Network Layout In Machine Picking Cotton

Machine picking cotton has been a large area in Xinjiang to promote,and achieved good results.But the layout of the pipe network,especially the arrangement of drip tape has not been systematically studied.There have been some undesirable phenomena.For example,the same area of the drip irrigation with different arrangements,irrigation plan using the traditional film drip irrigation mode under the irrigation plan,and the machine mode is used only for facilitates the mechanical picking.Therefore,this paper chooses the drip tape arrangements of several commonly used in the current cotton planting mode,the percentage of design length in design limit length of drip tape,and the drip flow of drip tape,as the basic parameters of the design in drip irrigation pipe of machine picking cotton.Through the economic evaluation and field soil moisture migration test method,compared with the design of the input and irrigation effect.To achieve the purpose of optimizing the design.The main conclusions are as follows:(1)The design of drip irrigation of machine picking cotton through different pipe network layout,this paper improves the calculation formula of Design of drip irrigation engineering.Using the formulaP = Sw/SL×100%to calculate the soil moisture ratio,the SL in the formula should be the average spacing of the adjacent drip tape of the whole plot.When calculating the time of irrigation,the amount of drip tape and the number of drip tape on each branch pipe,the drip tape spacing of the corresponding formula should be taken into account,which should be the drip tape average arrangement distance of the whole plot.At present,Design of drip irrigation engineering uses the arrangement distance of the capillary in a film to calculate the amount of the above,only applies to the whole site of the drip tape are equal spacing arrangement.(2)The economic evaluation of the 18 design schemes is carried out in this paper.Choose the best design scheme of economic evaluation result.The program is 1-4,2-2 and 3-5.Stepwise regression analysis using SPSS.The results show that the design of the one-time investment per acre,mainly affected by three factors.The three factors are the number of drip tape under the same film(X1),the drip flow of drip tape(X2),and the percentage of design length in design limit length of drip tape(X3).The model Y = 106.205X1 + 42.325X2 +112.222X3-78.849(R2=0.975)was obtained by stepwise regression.Under the condition of this study,this model could be used to calculate the one-time investment of the design.(3)Under the experimental conditions,the wet front migration velocity of the soil surface with the drip flow rate of 2.6 L/h was higher than that of the soil with the flow rate of 1.8 L/h.When the drip flow rate was 2.6 L/h,the migration velocity of soil surface wetting front showed a decreasing trend,while the wetting front speed of the soil surface when the drip flow was 1.8 L/h showed a decreasing trend and a mutation occurred.It is better to adopt the scheme of the machine picking cotton to arrange the water than adopt the arrangement of traditional the drip tape.According to the schemes a,b and c,it is found that the layout distance of the drip tape can be reduced in the machine mining mode,which can improve the wet uniformity of the soil under the film and improve the soil moisture environment of cotton growth.The irrigation soil moisture uniformity of schemes a and b are better than schemes c which is use of a membrane two tube capillary arrangement,and has a larger amount of irrigation.(4)The optimal design scheme is 2-2.Specific mode:1 membrane 3 drip tape and 6 row cotton,by 10 cm,66 cm,10 cm,66 cm,10 cm,the middle capillary is arranged in the middle position of the narrow row of cotton and the other two drip tapes are arranged in wide rows,and the distance of the middle position is 56 cm,dropper flow rate 2.6 L/h,the length of drip irrigation belt is 80%drip tape limit length.According to the research results,the optimization scheme of drip pipe network layout in machine picking cotton is determined.