Effects Of Sowing Date And Water Nitrogen Interaction On The Growth And Water Nitrogen Utilization Of Spring Maize Under Drip Irrigation In Hexi Region

Aiming at the problems of water shortage and low efficiency of water and fertilization utilization in agricultural production in Hexi Oasis Irrigation Area,field drip irrigation experiment was carried out in Shiyang River Basin agricultural and ecological water saving experimental station of Agricultural University of China.Three sowing dates were set,i.e.S₁:?2018.4.10?,S₂?2018.4.20?,S₃:?2018.4.30?,two irrigation water levels,i.e.I₈₀:80%ET_c,I₁₀₀:100%ET_c?ET_cis crop steaming?and four nitrogen application levels,namely F₀,F₁₂₀?120 kg/hm²?,F₁₈₀?180 kg/hm²?,F₂₄₀?240 kg/hm²?.The effects of sowing date and water nitrogen interaction on the growth,dry matter accumulation,yield and water and fertilizer utilization of spring maize under drip irrigation were studied and analyzed,which provided theoretical basis for reasonable sowing date and regulation measures of water and fertilizer.The main results are as follows:?1?The effects of sowing date and water nitrogen interaction on the growth index and yield of spring maize were revealed.The plant height,leaf area index and dry matter accumulation of maize were positively correlated with irrigation and fertilization,and water nitrogen interaction had a significant effect on yield.When the sowing date was delayed,the plant height increased first and then decreased.The yield of S₁I₁₀₀F₁₈₀treatment was the largest,which was 16830.29 kg/hm²,7.35%higher than that of S₂I₁₀₀F₂₄₀treatment,and14.29%less fertilizer,12.55%higher than that of S₃I₁₀₀F₁₈₀treatment.Timely early sowing?April 10?,100%ET_cirrigation amount and N-P₂O₅-K₂O 180-90-90 kg/hm²fertilization amount can be used as the optimal sowing,irrigation and fertilization model for Shiyang River Basin in Hexi Region.?2?The effects of sowing date and water and nitrogen interaction on the water consumption characteristics of spring maize were analyzed,and the daily water consumption intensity was the strongest from tastasing stage to filling stage.The water consumption modulus of spring maize was different under different irrigation and fertilization and sowing date,and the rule was from tastasing stage to>seedling stage to big trumpet mouth stage to>milk maturity stage.Water use efficiency was positively correlated with irrigation and fertilization.The water use efficiency of S₁I₁₀₀F₁₈₀treatment was 3.1 kg/m³,which was12.32%higher than that of S₁I₈₀F₂₄₀treatment.Under the condition of high nitrogen treatment,the irrigation water utilization efficiency of spring corn was the highest,and its average value was 3.64kg/m³.?3?Nitrogen and water against each spring sowing is discussed the influence of distribution of corn plant n uptake and utilization,increasing irrigation and nitrogen fertilizer will be conducive to maize plants on the absorption of nitrogen accumulation and n application rate of 240 kg/hm²,whole plant organs,stem,leaf and grain nitrogen accumulation quantity of along with the increase of n application rate rising trend will be vegetative organs of stem and leaf was S₃>S₂>S₁,and the n accumulation of grains was S₁>S₂>S₃.The overall variation rule of nitrogen distribution in different organs of spring maize under different sowing dates and water and nitrogen treatment was grain>leaf>stem>cob>bracts.The proportion of seed organs increased with the advance of sowing date,and increased with the increase of irrigation and fertilizer.Irrigation promoted the increase of nitrogen absorption efficiency and nitrogen fertilizer production efficiency,while nitrogen application inhibited the increase.The production efficiency of S₁I₁₀₀F₁₈₀treated nitrogen fertilizer was 93.5 kg/kg,which was 4.9%lower than that of S₁I₁₀₀F₁₂₀,but increased by 42.65%.When sowing date S₁?4.10?,irrigation of 100%ET_c,and nitrogen application of 180 kg/hm²,plant nitrogen uptake volume,accumulation and nitrogen utilization efficiency were the highest.?4?The influence of sowing date on the growth index of spring maize was discussed.LAI increased the fastest at effective accumulated temperature of about 600?,while LAI reached the maximum at effective accumulated temperature of about 950?,and leaf area index of S₃I₁₀₀F₂₄₀was the largest.In the range of 1500??2200?,the dry matter accumulation increased rapidly,and S₁I₁₀₀F₂₄₀had the largest dry matter mass,which was27.15t/hm².?5?The effects of sowing date on the growth process and accumulated temperature demand of spring maize were studied.Different sowing date had a significant effect on the duration of each growth stage of spring maize.The number of days in the growth period showed a decreasing trend with the postponement of sowing date.The whole growth period was shortened by 0.7-1.3d for every 1 day of postponement of sowing date and 0.1-0.3d for sowing date.The selection of a reasonable sowing date should avoid high temperature radiation and excessive rainfall during the grouting period.There was a significant positive correlation between the consistency of effective accumulated temperature and active accumulated temperature and the number of days of growth process.The accumulated temperature demand of early sowing maize was more in the flowering stage,and that of late sowing maize was more in the sowing stage and seedling stage.