Effects Of Straw Subsurface Irrigation On Growth And Yield Of Winter Wheat

Straw subsurface irrigation is a new type of underground irrigation method,which combines the advantages of underground irrigation and straw returning.Preliminary results have been achieved on the production,outflow and seepage test of stalk composite pipe.On this basis,in order to explore the actual use effect of stalk composite pipe in the field and the influence of straw subsurface irrigation on the growth and yield of winter wheat,find out the irrigation technical factors suitable for straw subsurface irrigation to promote the application of stalk composite pipe in the field,taking winter wheat as the research object,the orthogonal test of 3 factors and 3levels was carried out with pipe length,irrigation amount and pressure head as the main test factors,and the growth and yield of winter wheat were analyzed and studied with CROPWAT.The specific conclusions are as follows:1)When the pipeline length is 50 m,the irrigation amount is 25 L/m,and the pressure head is 0.8 m,the plant height of winter wheat at the mature stage is the largest.The pipeline length has the greatest influence on the plant height at the mature stage,and the pressure head has the least influence.When the pipeline length was 50m,the pressure head was 0.3 m,and the irrigation amount was 25 L/m,the leaf area index was the largest,which was beneficial to improve the photosynthesis of winter wheat,but the effects of various factors were not significant.When the pipeline length is 50 m,the irrigation amount is 15 L/m,and the pressure head is 0.8 m,the yield of winter wheat is the largest,the water consumption is the smallest,and the overall benefit is the highest.2)The three indexes of plant height,leaf area index and yield were normalized and analyzed.Combined with the objective function established with yield as the goal and the contribution rate of each factor,the optimal factor combination was selected as L₂A₃H₁,that is,when the pipeline length was 50 m,the irrigation amount was 25 L/m,and the pressure head was 0.3 m,it was most conducive to the growth and yield of winter wheat.3)CROPWAT model can well get the tundra and total water demand of winter wheat fertility,and the irrigation demand in different growth periods can be formulated and quantified according to the actual situation,which can be a good reference for the development of winter wheat irrigation system.4)The simulated irrigation water is relatively sufficient for 307.6 mm,the number of irrigation is 6 times,the irrigation interval is short,no yield phenomenon;the actual irrigation quota is smaller for 60 mm,in the critical period of winter wheat and combined with the actual precipitation time for a total of 3 irrigation,rainfall utilization rate is 99.4%,the yield reduction rate is 26%.The in-depth exploration of the stalk composite pipe is an important way for it to mature also provides more support and options for the stable development of national agriculture.The above findings provide some reference for the application of stalk composite pipe in combination with field crops,but due to the limited variety of crops studied,a higher degree of adaptation and a more complete system of pipe arrangement and irrigation system still needs to be explored more deeply.