Effect Of Deep Storage Irrigation On Soil Water Use,Crop Growth And Yield Of Winter Wheat

The crop production capacity in the Guanzhong area is constrained by water shortages caused by a temporal and spatial mismatch between rainfall supply and crop demand.It is of significantimportant to establish a scientifically and reasonably deep storage water irrigation strategy for optimizing water resource allocation and achieving stable and high crop yields.In this study,we used the soil reservoir storage function,planned the deep storage depth reasonably,quantified the water storage and irrigation water,and stored the surface water in the deep soil by irrigation with a large quota during the abundant water period according to the hydrological frequency analysis,and conducted a field experiment of deep storage irrigation of winter wheat in the Guanzhong Plain during 2021-2022,using Xiaoyan22 as the test variety and rainfed(CK)as the control,,and five deep storage and irrigation depths of 80cm(D80),120cm(D120),140cm(D140),160cm(D160)and 180cm(D180)were set.The main results obtained as follows:(1)Deep storage irrigation has a significant effect on soil moisture in winter wheat fields.The 0-100 cm soil of winter wheat was affected by the depth of water storage.After 7days of irrigation,the average water content of 0-200 cm soil layer in each treatment increased by 11.79%～18.97%.Deep storage irrigation can significantly reduce the consumption of effective soil water storage and replenish the deep soil moisture of farmland;when the water storage depth is greater than 80 cm,the average soil moisture of 0-300 cm farmland during the harvest period is above 17%,which is 13.36%～24.34% higher than that of CK treatment,indicating that water storage irrigation can effectively improve the soil water content and provide a good farmland water environment for crops in the next sowing period.(2)There was no significant difference in the height of winter wheat plants under different storage depths,but the leaf area index and SPAD values increased significantly compared with the CK treatment,and the maximum increase in leaf area index and SPAD values were 25.17%(D140)and 12.78%(D180)compared with the CK treatment.Water storage irrigation could increase the percentage of spike in biomass,and the percentage of80-180 cm water storage depth increased 0.16%～1.79% compared with CK.Meanwhile,water storage irrigation could prolong the time of maximum filling rate appearance and active seed filling period of winter wheat,increase the average filling rate and maximum filling rate of winter wheat,and then improve the quality of winter wheat seeds with different deep storage depth.Compared with CK treatment,the yield of winter wheat with different storage depth increased by 8.85%(D80),24.7%(D120),30.9%(D140),17.9%(D160)and 9.8%(D180),respectively.(3)Deep storage water irrigation can generate a leakage supply of 48.87-140.74 mm,which can supplement soil moisture in deep soil layers.The water consumption of winter wheat under different deep water storage irrigation conditions ranged from342.03 mm to460.30 mm during the whole reproductive period,with the lowest percentage of water consumption from effective rainfall(43.72%)in the D120 treatment and the highest percentage of water consumption from soil storage in the CK treatment.Deep storage irrigation significantly improves the rainfall use efficiency,compared with CK treatment,the rainfall use efficiency increases 8.87%～31.01% at different storage depths.Through comprehensive analysis,it was found that setting the water storage depth at 140 cm can optimize the allocation of water resources,increase the amount of water stored in the field,achieve high-yield targets,and maximize benefits.