Effects Of Different Nitrogen Rates On Soil Nutrients And Microbial Of Wheat Field Under Nighttime Warrming Before Anthesis

Global warming has caused a foreseeable impact on agricultural production.Winter and spring that winter wheat mainly grown in response to climate warming is more pronounced,nighttime warming is higher than daytime,and underground is higher than aboveground.In recent years,excessive nitrogen fertilizer led to increasingly deterioration of soil environment and nutrient imbalance.In order to investigate the variation of soil physical and chemical environment,nutrient content,enzymes and microbial activity to different nitrogen rates under nighttime warming before flowering of winter wheat.This study set the double factors of open nighttime warming?W1:warming,W0:not warming.The same is as below?before flowering and different nitrogen rates(N1:150 kg-ha^-1,N2:225 kg-ha^-1,N3:375 kg-ha^-1.The same is as below)field experiment.It has great significance to adjust winter wheat crop cultivation and fertilizer management reply to future climate warming.Conclusions are as follows:1.Temperature of underground increased 1.5 ? under open nighttime warming,and aboveground was 0.9 ?.Warming obviously increased ?0 ? accumulated temperature before flowering.Warming led to soil moisture obviously decreased.Nitrogen very significantly reduced soil pH under warming,respectively 0.13%?0.54%?1.23%by N1?N2?N3.Two years' warming led to basic soil pH reduce 2.92%.Warming reduced root water content and root activity of winter wheat.Root activity reduced as nitrogen rates droped,and significantly in jointing.2.Warming decreased soil available phosphorus in maturiy,and soil available potassium of seedling,jointing and heading.Warming significantly increased soil organic matter of seedling and heading.Different nitrogen rates significantly affect soil nitrate N and soil ammonium N of winter wheat in ever period,as N3 significantly increased soil nitrate N and soil ammonium N.Different nitrogen rates significantly affect soil available phosphorus and soil available potassium,as they were highest under N1.Mutual function of warming and nitrogen to soil total N,soil available phosphorus and soil organic matter is the most important.3.Warming before flowering affected soil invertase activity,and significantly promoted soil catalase activity of heading and maturiy.W1 significantly increased soil bacteria biomass and activity,improved richness and estimator of soil bacteria,and led to similarity and overlap rate larger between N1,N2 and N3.Effect of nitrogen to soil urease activity is bigger than warming.N3 significantly reduced soil urease activity of jointing,heading and flowering.N3 significantly increased soil invertase activity of jointing and maturiy.Soil catalase activity was promoted under N1,and jointing was significantly.OTU numbers of soil bacteria by N1 and N3 increased 3.4%and 3.0%under warming,respectively,but it decreased 4.0%by N2.Richness and estimator of soil bacteria is decreased with the increase of nitrogen.Mutual function of warming and nitrogen to soil urease activity of jointing and flowering was very significantly,and soil catalase activity of jointing,heading and flowering had significantly influence.W1N1 promoted soil bacteria biomass and activity,W0N1 secondly.Effect of W1N1 and W1N3 to increase soil microbial biomass carbon was better.Soil microbial biomass nitrogen was largest under W1N3.Production efficiency of nitrogen fertilizer,agronomic efficiency of nitrogen fertilizer,and application rate of nitrogen fertilizer were highest under W1N1.Thus,appropriately reduce nitrogen rate was beneficial to slow down soil acidification and ammonia poisoning,and recovery health of soil environment,meanwhile save cost under climate warming future.