Effects Of Rainfall Harvesting With Water-saving Irrigation Cultivation On Soil Moisture&Temperature Environment And Growth Of Winter Wheat

In this research, the soil moisture-temperature environment and growth of winter wheatin sub-humid areas were analyzed comparatively by setting different cultivation systems ofroot domain rainfall harvesting with no irrigation, rainfall harvesting with supplementaryirrigation, traditional rain-fed cultivation and border irrigation cultivation. The mainconclusions are as follows：1. Rainfall harvesting with water-saving irrigation cultivation can effectively improvethe soil moisture content in0~200cm soil layer，performance in0~60cm shallow soil wasmost obvious. Seedling stage to the middle of filling，effects of soil moisture conservationunder rainfall harvesting with water-saving irrigation cultivation processed with the advanceof growth；the middle and late stage of filling to maturity，effects of soil moistureconservation under rainfall harvesting with water-saving irrigation cultivation diminishedalong with the significant increase of rainfall. Irrigation significantly improved soil moistureconditions in regreen period and water consumption in the whole growth time of crop，effectof soil moisture conservation diminished with the advance of growth. Rainfall harvesting withno irrigation cultivation could more significantly increase the soil moisture and waterconsumption in the whole growth time than rain-fed cultivation；the soil moisture underrainfall harvesting with supplementary irrigation cultivation was higher and the waterconsumption was significantly lower than border irrigation cultivation，had great changes onwater status of wheat. Under the same planting conditions，the soil moisture under60cmfurrow width was better than it under40cm furrow width，there was no significant differencesbetween the two.2. Effects of different cultivations on soil temperature was different，the specific effectsgradually weakened along with the deepening of the soil. In the early stages (seeding andwintering)，the temperature performances under different cultivations was：rainfall harvestingwith60cm furrow width>rainfall harvesting with40cm furrow width>rain-fed cultivation，and rainfall harvesting had some insulation，and the insulation effects with broadband typewas better than the narrowband. In the middle and later periods（regreen-maturity），the temperature performance under different treatments was： rain-fed cultivation>borderirrigation cultivation> rainfall harvesting with no irrigation of60cm furrow width>rainfallharvesting with supplementary irrigation of60cm furrow width>rainfall harvesting with noirrigation of40cm furrow width>rainfall harvesting with supplementary irrigation of40cmfurrow width，every rainfall harvesting had certain cooling effects，that could effectivelyreduce the temperature difference during the whole growth and avoid high temperature stressin later growth stage. Under the same planting conditions，temperature of Irrigation treatmentswere lower than no irrigation treatments.3. Rainfall harvesting cultivation had significant impacts in the whole growth period ofwinter wheat. In seedling stage，the time of seedling tiller was earlier under rainfall harvestingcultivation than others；after regreen period，the growth process was delayed under rainfallharvesting cultivation compared with rain-fed cultivation and border irrigation cultivation.The every growth process was delayed1~2d under rainfall harvesting with supplementaryirrigation compared with rainfall harvesting with no irrigation. The indexes of plant height，dry matter and stem number under rainfall harvesting were better than rain-fed cultivation andborder irrigation cultivation，better promoted the winter wheat growth. Rainfall harvestingwith supplementary irrigation could further promote the growth of winter wheat on the basesof rainfall harvesting with no irrigation than others. The growth conditions of winter wheatunder60cm furrow width were better than it under40cm furrow width.4. Rainfall harvesting with water-saving irrigation cultivation effectively improved theN，P，K use efficiency of crops，reducing the invalid loss of fertilizer，coordinating therelationship between soil moisture and fertilizer well，effectively increasing the nutrients tothe grain and other "bases". The N，P，K use efficiency under rainfall harvesting with noirrigation T1，T3were more significantly improved than that under traditional rain-fedcultivation T5. Fertilizer use efficiency under rainfall harvesting with supplementaryirrigation cultivation was not lower，which was due to the reduce of irrigation amount，thanborder irrigation cultivation with adequate irrigation. The N，K use efficiency under T2werehigher than which under T6，and the fertilizer use efficiency between T4and T6were nosignificant differences. Under the same furrow width conditions，the fertilizer use efficiencyunder irrigation treatments were higher than which under the corresponding free irrigationtreatments. Compared between different furrow width，the fertilizer use efficiency under60cm furrow width was significantly higher than which under40cm furrow width，consistentwith the soil moisture condition.5. The findings of this study are：the effects of yield-increasing and water-saving underrainfall harvesting with no irrigation were more significant than rain-fed cultivation，efficient use of rainfall can be realized. Furthermore，the experiment showed that，it could maintain thesame output levels between rainfall harvesting with half amount of irrigation and borderirrigation cultivation with sufficient irrigation，and rainfall harvesting with supplementaryirrigation significantly increased water use efficiency，and the purposes of efficient use ofirrigation water and save irrigation were realized. In addition，the effects of yield-increasingand water-saving under60cm furrow width were better than that under40cm furrow width.Because of the significant yield-increase effect with irrigation，so in the area，rainfallharvesting with supplementary irrigation cultivation which combined with little irrigation isthe ideal yield-increasing and water-saving planting for the region，which could make the dualefficient use of rain and irrigation.