| In response to the traditional farming mode in North China,there are common problems that the soil plough layer is shallowing year by year,the plough bottom layer is thicker,the ability of the plough layer soil to retain water and fertilizer and the irrigation quality is not high.In this study,wheat and summer maize rotation crops as the research object,the subsoiling 40 cm+rotary tillage 15 cm?PS?before winter wheat sowing were designed total of six test treatments combinations with different border fields?border length 50 m,border width,1.7 m,3.4 m,5.1 m?and inflow rate(30 m3·h-1,40 m3·h-1).Conventional rotary tillage 15 cm with border width 3.4 m were used as controls?CK?.The experimental research on soil physical properties,soil infiltration performance,irrigation flow movement and crop growth and development was carried out in Xinxiang Comprehensive Experimental Base of the Chinese Academy of Agricultural Sciences from 2016 to 2017.The purpose of this paper was carried out the research of subsoiling soil infiltration and broad irrigation flow advance and irrigation technical parameters and The Kositiakov model was infiltrated,and the technical parameters of border irrigation under subsoiling cultivation were simulated and the irrigation quality was analyzed and evaluated.The results were as follow:?1?Studying the soil physical characteristics and soil water content in subsoiling cultivation methods was found that subsoiling tillage can improve the soil bulk density,porosity and compactness,and significantly reduced soil bulk density in 0-40 cm soil layer and soil compaction in 20-30 cm soil layer increase soil porosity,and increase soil moisture content in 0-100 cm soil layer and soil water storage in0-60 cm soil layer in a certain extent.?2?Revealing and simulating irrigation flow advance and soil infiltration characteristics under subsoiling cultivation methods,and found that the inflow and width of irrigation have a certain influence on the flow advancing time;When the inflow(40 m3·h-1)and width?3.4 m?were constant,the advancing time of subsoiling tillage irrigation was 5.32 min longer than that of the control.The flow advance data was fitted by exponential function,and the coefficient of determination R2 was above 0.9.Compared with conventional tillage,the initial soil infiltration rate,stable infiltration rate,average infiltration rate,and accumulative infiltration amount increased by 41.53%,50.08%,12.58%,and 12.44%,compared with CK respectively.The Kositiakov infiltration model can be used to better simulate the infiltration process of winter wheat in the jointing stage.The coefficient of determination R2 is 0.920.96,the infiltration coefficient a before irrigation is 11.20,and the infiltration index b is 0.62.The infiltration coefficient a after irrigation was 8.16,and the infiltration index b was 0.83.Subsoiling cultivation significantly improved soil saturated hydraulic conductivity at the depths of 20 cm and 40 cm after sowing of winter wheat.?3?The effects of subsoiling cultivation on crop growth characteristics,yield and water use efficiency were analyzed.It was found that subsoiling cultivation had play a certain role in promoting the growth and development of winter wheat and summer maize,and its plant height,leaf area index and the amount of dry matter accumulation,yield,and yield components are significantly higher than traditional tillage.The water use efficiency was increased by 24.61%and 23.11%compared with traditional tillage.Under the subsoiling cultivation method,the combination of technical parameters of border irrigation with a width of 3.4 m and a flow rate of 40 m3·h-1 was adopted.The crop water use efficiency was the highest,and the water-saving yield increase effect was significant.?4?The WinSRFR model was used to simulate the process of subsoiling tillage border irrigation and to evaluate the irrigation quality.The simulation results were better.The ARE of different treatments was22%29%.The average irrigation efficiency of PS was 86%,and the average uniformity was 81%,which was 2.76%and 4.95%higher than that of conventional cultivation.Among them,under the subsoiling cultivation method,the irrigation efficiency is 95%with a width of 3.4 m and the flow rate of 40 m3·h-1,and the irrigation uniformity is 86%,which is better than other treatment combinations and the irrigation quality is better.?5?Through the analysis of comprehensive factors such as crop yield,water use efficiency,and irrigation quality assessment,the optimal combination of technical parameters for border irrigation under subsoiling cultivation is selected.Obtained subsoiling tillage 40 cm+rotary tillages 15 cm,length 50 m,width 3.4 m,inflow rate 40 m3·h-1,slope 0.0019,cutoff time 0.39 h,roughness 0.211,the infiltration index a value of 0.638 and the infiltration coefficient K value of 118.444 mm·h-a are most suitable for the technical parameters of border irrigation. |
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