Effects Of Irrigation With Micro-sprinkling Hoses On Soil Water Distribution And Water Consumption Characteristics And Grain Yield Of Winter Wheat

To study the effects of irrigation with different configuration setting micro-sprinklinghoses on soil water distribution and water consumption characteristics and grain yield ofwinter wheat, field experiments were conducted in2011~2012growing seasons. Eightirrigation treatments were designed: T0, no irrigation during the whole growth stage; T1toT6, irrigation with different folding diameter and aperture configuration settingmicro-sprinkling hose; T7, traditional border irrigation. The length of micro-sprinkling hoseswere all60m, the sprinkling angle of micro-sprinkling hoses were all80°. Every orifice groupincludes6orifices which are arranged on the hose in a single-oblique fashion. the aperture oforifices in both ends of orifice group (end-orifices) are1.2mm, the aperture of the other4orifices in the middle of orifice group (mid-orifices) were changed with different treatmentdesign. The folding diameter of micro-sprinkling hose is60mm in T1and T2,80mm in T3and T4,100mm in T5and T6; the aperture of mid-orifices are0.8mm in T1, T3and T5, and1.0mm in T2, T4and T6, respectively. The micro-sprinkling hoses were laid along theinter-row of wheat with four rows on each side of the hose. The actual irrigation width of eachhose is1.6m. Each micro-sprinkling irrigation uses the method of supplemental irrigationbased on measured soil moisture to determine the amount of irrigation.Inflow cutoff ratio ofthe traditional border irrigation is90%, irrigation amount according to the actualmeasurement (130.62mm).1、Effects of different treatments on Soil Water Distribution and Water ConsumptionCharacteristics.Irrigation with micro-sprinkling hoses at jointing stage, the soil water content in0-200cm soil layers in each inter-rows had no significant difference in the first half of theborder(0~16m) in each irrigation treatment. The inter-rows soil water content in0~60cm soillayers decreased with increasing the distance between the inter-row and the hose in the middleand posterior segment of the border (29~60m) in T1and T2treatments. The inter-rows soilwater content in0~60cm soil layers decreased with increasing the distance between theinter-row and the hose in the posterior segment of the border (44~60m) in T3and T5treatments.The uniformity of irrigation water horizontal distribution in T4was higher than that of the other treatments. The distribution and dynamics of irrigation water in the soil in T6and T7were the same as those in T4. Irrigation with micro-sprinkling hoses at anthesis stage,the distribution of soil water in each treatment is consistent with that in jointing stage.However, the inter-rows soil water content in0~100cm soil layers decreased with increasingthe distance between the inter-row and the hose in the first half of the border in T1, T2, T3and T5, and compared with jointing stage’s the difference became significantly lager. The soilwater content in0~60cm soil layers farther away from the head of the border the difference ismore obvious. The uniformity of irrigation water horizontal distribution in the borderirrigation is higher than irrigation with micro-sprinkling hoses’ after jointing stage irrigation.The soil water consumption amount in0~40cm soil layer from jointing to anthesis inT4was lower than that in the other treatments. The soil water consumption amount in80~200cm soil layer in T4was close to that in T6, but lower than that in T0, T1, T2, T3andT5. The soil water consumption amount in0~80cm soil layer from anthesis to maturity in T4increased significantly, while that in80~200cm soil layer was lower than that in the othertreatments. The irrigation amount in anthesis, total irrigation amount and total waterconsumption amount in growing season in T4were significantly lower than those in the othertreatments.The total total irrigation amount in growing season in T7is significantly higherthan those in the other treatments, but the total irrigation amount, total irrigation amount issignificantly higher than those in the other treatments.The water consumption amount, waterconsuming intensity and the amount of water consumed coefficient were significantly higherthan those in T4from jointing to anthesis stage and anthesis to maturity stage. The soil waterconsumption amount in0~40cm soil layer is significantly higher than T4.2、Effects of different treatments on nitric nitrogen and nitrogen accumulation, distribution inwheatThe content of nitrate nitrogen of every treatment in0~80cm soil layer was higher atanthesis than those at jointing. At anthesis stage, the nitrate nitrogen content of T0and T2in80~200cm soil layer was significantly lower than than those at jointing. There was nosignificant difference between anthesis stage and jointing stage in the nitrate nitrogen contentof T1, T3, T4, T5and T6in80~100cm soil layer; The nitrate nitrogen content below100cmsoil layer was lower than those at jointing stage. It indicated that measuring moisture did notlead the soil nitrate leaching to below80cm soil layer at jointing stage. Irrigation withconfiguration setting micro-sprinkling hoses, end-orifices are1.2mm, mid-orifices are1.0mmand the folding diameters are80mm(T4) and100mm(T6), promoted absorption of the nitratenitrogen in0~40cm soil layer during jointing and anthesis stage, significantly increased absorption and utilization of the nitrate nitrogen in0~80cm soil layer after anthesis. Theborder irrigation lead the soil nitrate leaching to the deep soil layer. Nitrate nitrogenaccumulating in the60~160cm layer.It indicated that irrigation with the suitable orifices and folding diametersmicro-sprinkling hoses and the border irrigation can promoted the nitrogen assimilation afteranthesis. Promoting the assimilation and accumulation of nitrogen after anthesis, increasingtransfer nitrogen storage amount of vegetative organs before anthesis to grains, increasing theproportion of the distribution of nitrogen in the grain, but the ratio of nitrogen translocated tograin decrease.3、Effects of different treatments on physiological basis, dry matter accumulation anddistributionThe whole growth stage with no irrigation or uniform irrigation decreased the flag leavesmaximal photochemical efficiency at the late stage of grain filling in wheat. Irrigation withconfiguration setting micro-sprinkling hoses, end-orifices are1.2mm, mid-orifices are1.0mmand the folding diameters are80mm(T4) and100mm(T6), it can keep high leaf waterpotential after anthesis, keep normal photosynthesis and transpiration of water, keep thehigher actual photochemical efficiency of flag leaf in the middle and late period of grainfilling, improve photosynthetic rate, promote photosynthetic assimilation, significantlyincreased the grain filling rate and grain weight,which is the physiological basis for highyield.Irrigation with configuration setting micro-sprinkling hoses, end-orifices are1.2mm,mid-orifices are1.0mm and the folding diameters are80mm, promoting the dry matterdistribution and accumulation in different organs at anthesis stage, significantly improving thedry matter assimilation capacity of wheat after anthesis, increasing the distribution andaccumulation amount of dry matter in grain, stem+sheath and ear axis+glume at maturitystage.The border irrigation significantly improved the dry matter assimilation capacity ofwheat after anthesis, but decreased the dry matter in vegetative organs translocating tograin.4、Effects of different treatments on grain yield, water use efficiencyThe spike number、the1000-grain weight、the grain yield、the rain water and soil waterues efficiency in T0is the lowest. The yield water use efficiency、irrigation water useefficiency and irrigation benefit in T4were hightest in the micro-sprinking irrigationtreatment.Results indicated that suitable bandwidth and aperture configuration can improve soil water distribution uniformity, so it can increase grain yield and water use efficiencysignificantly. There was no significant difference between border irrigation(T7) and T4、T6onthe grain yield, but the yield water use efficiency、irrigation water use efficiency and irrigationbenefit in T7were significantly lower than those in T4and T6. Under this experimentalcondition, T4treatment was considered to be an optional treatment for water-saving andhigh-yielding production.