Study On Saline Corn Slow-release Fertilizer Of Slow-release Nitrogen Proportion

Maize is very important in agricultural production in Shanxi Province.Maize sown area was 36750ha,which is more than 1/3 of the total sown area in Shanxi.The maize production accounts for 65%of total grain output in Shanxi.There were some problems in recent years such as high input cost,low utilization of nutrient,overuse of high nitrogen fertilizer,and deterioration of soil environment.Slow release fertilizer special for maize which requires less human labor/time and has high nitrogen utilization rate is one of effective approach to solve these problems existing in the production of maize.The main maize planting area-North Shanxi is also widely distributed with saline land,high pH and salinity properties of salind land are main factors that limits maize yield.In the foundation of screening spring maize which in high nitrogen slow-release special coated fertilizer materials grow in salt area of north Shanxi.This work mainly foucsed on finding the best nitrogen ratio of medium to slow-release part in maize product.The optimized coated fertilizer for spring maize grown in saline alkali soil was determined through a series of fertilizer release test.Under pot,buried bag and field conditions,5 different slow-release nitrogen proportion(0%,25%,33%,50%,67%)tests were conducted to study the spring maize yield,its components,dry matter accumulation,plant nitrogen uptake,nitrogen utilization rate and the change of soil pH and EC.The results were shown as below:1 At 25 ?,the differently coated urea relase was studied via hydrostatic cultivation.It was shown that the initial release rate of sulfur coated urea hydrostatic release is high,above 23%,however,"tailing effect" and "locked-in effect" becomes obvious in later period.The hydrostatic release pattern agrees with release pattern in field and nitrogen absorption of Spring Maize.III2 Thorugh soil embedded method,different fertilizers' soil release was studied.The results shown,sulfur coated urea has better release rate in field than in hydrostatic enveriment.The release rate in maize mature period can reach 80%.The daily average release rate of slow release fertilizer is bigger in soil than in water.The maximum daily average release rate of sulfur coated urea in the slight saline alkali soil is more than 2%.3 Through the pot buried bag test,different corrosion effect of nitrogen added proportion of nitrogen release rules,the growth of spring maize and its effect on root and root zone soil was studied.The results showed that all the different slow release nitrogen addition proportion treatments increase maize yield per plant,increase the amount of nitrogen uptake,and improve the utilization rate of nitrogen,at the same time,the underground part of nitrogen absorption was also improved significantly,the maize root and root rhizosphere soil pH were also improved,the poison of high saline alkali soil pH of maize was reduced.Among them,adding slow-release nitrogen ratio for 33%gives a more complete release,nitrogen utilization rate was increased by 14.76%,after the harvest,the aboveground and belowground dry matter accumulation were increased by 20.10%and 13.09%,N uptake were increased by 15.40%and 21.11%,nitrogen accumulation and release rate was more than 96%,urea and ordinary bottom disposable application compared,maize yield was increased by 73.83%,compared with before sowing,0-20cm soil pH value was decreased by 0.09,this proportion is of more in line with the spring maize on nitrogen uptake.4 In order to study slow release nitrogen addition proportion effect on growth of spring maize and environment of fertilizer bags in the field environment of saline alkali land through the method of burying bags in the field.The results showed that the combined application of corrosion effect of nitrogen on maize field growth and pot experiment are consistent.The results also further verify the fertilizer slow-release nitrogen treatment is more effective to the formation of spring maize growth and yield.At the same time,fertilizer around the soil pH value change and pot root rhizosphere soil change trend is consistent,the optimized slow effect nitrogen adding proportion was 33%.After harvest,the 33.98%higher than common urea single basal application of maize yield,nitrogen utilization rate of was increased by 30.91%,0-20cm soil pH value was lowered than before sowing by 0.23.5 The effect of different slow rate of nitrogen addition on the actual production of maize was verified by the large area cultivation of Maize in the field.Results showed that adding corrosion effect of nitrogen significantly increased nitrogen utilization rate in saline alkali soil of spring maize,the optimized slow release fertilizer adding proportion is 33%which increases yield most effectively.under this condition,the yield was increased by 42.23%compared to common urea production.At the same time,nitrogen utilization rate was increased by 33.89%,effectively improve the quality of maize;After applying fertilizer slow-release nitrogen,the topsoil pH and EC values were reduced,the combined application of 33%of sulfur coated urea treated 0-20cm soil pH was reduced by 0.46,EC value was decreased by 0.011 ms/cm,which effectively improved the saline alkali land corn planting soil environment.Through this work,it can be concluded that the application of nitrogen fertilizer effectively improves the nitrogen utilization rate of maize,increase the yield of maize,and improves the environment of saline alkali soil.Among them,the optimized adding proportion was 33%.