Effects Of Aerobic Freshwater And Brackish Water On Growth Characteristics Of Spring Wheat

The shortage of fresh water resources severely restricts agricultural production in my country,and the application of water-saving technologies has become an urgent need.This paper aims to improve the efficiency of irrigation water utilization and reduce the risk of secondary salinization,combining oxygenation technology with the efficient use of irrigation water,taking spring wheat as the research object,through soil column infiltration and cultivation test,wheat germination test and spring wheat The pot experiment started the research and mainly got the following conclusions:(1)Brackish water is conducive to soil water infiltration,aerated fresh water will inhibit soil water infiltration,and aerated salt water will promote soil water infiltration.Oxygenated freshwater infiltration in shallower soil layers can increase the concentration of dissolved oxygen in the soil and prolong the consumption time of dissolved oxygen in the soil,while infiltration of brackish water will accelerate the consumption of dissolved oxygen in the soil.The infiltration of oxygen-enhanced brackish water can also make the dissolved oxygen of the soil reach a higher concentration than that of fresh water treatment,and will prolong the consumption time of dissolved oxygen in the soil.The soil salt content fluctuated in the early stage of cultivation,and the aerated water was more volatile than the non-aerated water,and gradually stabilized in the later period.Oxygenated water infiltration can promote the rapid generation of nitrite nitrogen and nitrate nitrogen;brackish water treatment will delay the formation of nitrite nitrogen and ammonium nitrogen,and will accelerate the consumption rate of nitrite nitrogen and ammonium nitrogen;Oxygenated brackish water can improve the rapid consumption of brackish water to inorganic nitrogen.(2)Brackish water with a salinity of 2 g/L is more conducive to wheat seed germination.Oxygenated fresh water can increase the number of wheat seeds germinated on the fourth day of germination,but it inhibits the weight of young roots and the average height of young buds during wheat seed germination;excessively high dissolved oxygen concentration will inhibit the germination of wheat seeds.Wheat seeds under different salinity brackish water aeration treatments showed different suitable dissolved oxygen concentrations.Through correlation and significance analysis,it was found that the germination rate had a good correlation with the salinity and dissolved oxygen concentration,and the germination rate,salinity and dissolved oxygen concentration of wheat seeds under oxygenated brackish water irrigation were established.Between the empirical models,the fit is good.(3)Brackish water irrigation will increase the soil moisture content of the main root zone from spring wheat sowing to jointing stage,while aerated water irrigation will reduce the soil moisture content of the main root zone from spring wheat sowing to jointing stage;Irrigation with brackish water and aerated water during maturity will increase the soil moisture in the main root zone of spring wheat.Compared with the non-aeration treatment,the aeration-treated soil as a whole has a higher average salt content.Both aerated freshwater treatment and brackish water treatment can promote the conversion of urea to ammonium nitrogen,and the conversion time of aerated freshwater treatment is earlier.The distribution of available phosphorus in each treatment was similar to that of nitrate nitrogen and ammonium nitrogen.Brackish water treatment is conducive to the increase of the available potassium content in the surface layer of the soil,and aerated fresh water treatment is not conducive to the increase of the available potassium content in the late spring wheat growth period.(4)Oxygenated freshwater treatment is only conducive to the growth of plant height,leaf area,and aboveground biomass of early spring wheat(0-45 d).The brackish water treatment had an adverse effect on the early growth stage of spring wheat.Oxygenated brackish water significantly promoted the growth of plant height,leaf area and above-ground biomass in the late growth stage of spring wheat.(5)Logistic growth model and modified Logistic growth model can better simulate the change trend of spring wheat plant height,leaf area index,aboveground biomass with growth time,and the change trend of theoretical maximum value of plant height,leaf area index,aboveground biomass All of them are aerobically brackish water>fresh water treatment>bracky water treatment>aeration treatment.