Analysis Of Shallow Covered Drip Irrigation System And Agricultural Water Saving Potential For Maize In Korqin District,Tongliao City

Located in the eastern part of Inner Mongolia,Korqin District of Tongliao City is one of the main production areas of corn in China.The irrigation water use efficiency and water use efficiency in the region has been low due to traditional irrigation methods(large water irrigation and low-pressure pipe irrigation),so since 2018,we have started to retrofit the irrigation method-transition from traditional irrigation to shallow covered drip irrigation(SCDI),and by 2020 we have completed 8.45×104hm2 of land to be retrofitted.In order to investigate the water-saving and high-yield irrigation system and predict the agricultural water-saving Potential of the region,this experiment was conducted in 2018 and 2019 with "Jingke 968" as the test material for spring maize shallow covered drip irrigation trial.Afterwards,this paper set the irrigation quota for the control group SCDI-ck at 3000 m3/hm2,and the irrigation quota for SCDI-1,SCDI-2 and SCDI-3 at 2700 m3/hm2,2250 m3/hm2 and 1800m3/hm2,respectively,and the optimal irrigation system was Proved to be 2250 m3/hm2 in the two-year trial.The optimal water-efficient irrigation system was studied from2020 onwards based on the Previous two years’ experiments,therefore,five treatments were set up,denoted as SCDI-1,SCDI-2,SCDI-3,SCDI-4,and SCDI-5,with irrigation quotas of 2250 m3/hm2,1950 m3/hm2,1800 m3/hm2,1650 m3/hm2,and1500 m3/hm2,respectively.The differences between non-sufficient irrigation on Physiological traits,canopy temperature,water consumption,yield,water use efficiency and irrigation water use efficiency of maize throughout the reproductive Period at different irrigation rates were analyzed to derive the irrigation system with optimal water saving efficiency.On this basis,the agricultural water saving potential of the region was analyzed by combining the data provided by the water resources bulletin of Korqin District,Tongliao City and the local water bureau in recent years.The following conclusions were drawn.(1)Throughout the maize reproductive period,plant height and leaf area index showed a trend of increasing and then slightly decreasing,while dry matter accumulation gradually increased and reached a maximum at maturity.The 2020 data showed that spring maize plant height,leaf area index and dry matter accumulation were positively correlated with irrigation quotas,i.e.,they increased with increasing irrigation quotas as follows: SCDI-1>SCDI-2>SCDI-3>SCDI-4>SCDI-5.(2)The water consumption(ET)of maize in Tongliao City in 2020 was the highest in the spatulation-filling period,except in the seedling and pulling periods,which were affected by rainfall,similar to the Previous two years’ experiments.Under shallow covered drip irrigation,water consumption of corn increased with increasing irrigation quotas as follows: SCDI-1>SCDI-2>SCDI-3>SCDI-4>SCDI-5.(3)The 2020 data showed that irrigation quotas was positively correlated with maize seed yield and negatively correlated with water use efficiency(WU E)as SCDI-1>SCDI-2>SCDI-3>SCDI-4>SCDI-5,and irrigation water use efficie-ncy(IWUE)as SCDI-1<SCDI-2<SCDI-3<SCDI-4<SCDI-5.Taking into account the maize grain yield,water use efficiency and irrigation water use efficiency,SCDI-1 grain yield was still higher than the other treatments,but in terms of water saving efficiency,SCDI-2 had no significant effect on yield while saving water(P>0.05),so SCDI-2,with an irrigation quota of 1950 m3/hm2,could be formulated as the irrigation system with the highest water saving efficiency.(4)Under the condition of SCDI-2 non-sufficient irrigation system,119 million m3 of water resources can be saved com Pared with SCDI-1.