Effects Of Controlled-release Nitrogen Fertilizer Regulation On Winter Wheat Growth And Water And Nitrogen Utilization

It is of great significance to study the technology of efficient utilization of water and fertilizer in wheat production to realize the goals of saving water and fertilizer in agricultural production and simplifying the production process.Taking the wheat variety"xiaoyan 22"as the experimental crop,Three proportions of controlled-release nitrogen fertilizer and ordinary urea were set,respectively:8:2(N2),7:3(N3)and 6:4(N4);There are 2 fertilization methods,namely,the one-time application of mixed fertilizer(C,referred to as base application)and the basic application of controlled-release fertilizer+topdressing of urea(T,referred to as topdressing);At the same time,three controls were set:No fertilization(CK0),pure common urea applied in ratio of basal and topdressing of 4:6(CK1),and pure controlled-release urea once basal applied(CK2).In order to obtain a nitrogen application model that can increase winter wheat yield and increase water and nitrogen utilization efficiency,the effects of the fertilizer method and fertilizer ratio of controlled-release nitrogen fertilizer with urea on the growth physiological indexes,grouting characteristics,yield,water use efficiency and nitrogen utilization of winter wheat were discussed.The results show that:(1)hlorophyll content showed an increasing trend as the proportion of controlled release nitrogen fertilizer increased.Compared with the control group,the appropriate fertilization method and fertilizer ratio significantly increased the chlorophyll content and leaf area index,and maintained a high level during the grouting period.(2)the method of fertilization and the proportion of fertilizer played a regulatory role in the accumulation of dry matter on the overground.Compared with CK1,TN2 and CN3treatments significantly increased the accumulation of dry matter on the overground at the maturity stage,by 8.79%.The dry matter accumulation process was shown as follows:the base application of mixed fertilizers promoted the dry matter accumulation before the jointing period,while application of controlled-release nitrogen+topdressing urea increased the dry matter accumulation.The growth rate of dry matter after flowering was3.98?5.16 t/hm~2,contributing 60.1%?64.56%,which was the main source of seed quality formation.TN2 treatment after flower transshipment volume and after flower contribution rate is the largest.(3)A reasonable proportion of controlled release nitrogen fertilizer with urea and fertilization method can effectively control the characteristic parameters and yield composition parameters of grain filling,optimize the grain filling process of winter wheat,and promote the improvement of grain quality and yield.The rational application of urea can ensure that the material source of grouting is more sufficient,improve the initial growth potential of grains,coordinate the relationship between reservoir and source,and extend the grouting time.In the treatment of one-time use of mixed fertilizers,the grain quality was improved mainly by increasing the maximum grain-filling rate and delaying the maximum grain-filling rate,and the contribution to grain quality was mainly shown in the gradual and rapid growth periods.(4)the yield of CN3 and TN2 treatment was the highest,with no significant difference.When the mixture ratio of controlled-release nitrogen fertilizer and common urea was 7:3,the one-time basal application mainly improved the grain quality by increasing the maximum grouting rate and delaying the maximum rate,and ensured a higher effective panicle number by tiller number,thus improving the yield;When the ratio of controlled-release nitrogen fertilizer+topdressing urea in the early stage was 8:2,the effective panicle rate could be ensured to be higher,the grain quality accumulation could be improved by extending the grouting duration and the growth ratio in the slowing period,and the better 1000-grain weight could be obtained,so as to increase the yield.(5)TN2 treatment showed the best nitrogen apparent utilization rate,nitrogen agronomic utilization rate and partial productivity of nitrogen fertilizer,which were 42.41%,40.37%and 15.15%higher than CK1 treatment,and 31.58%,31.58%and 18.14%higher than CK2 treatment,respectively.Moreover,the nitrogen dependency rate in TN2 treated soil was the smallest,which was 17.15%and 13.82%lower than that in CK1 and CK2,respectively.(6)nitrogen application significantly improved water use efficiency,and fertilization method,fertilizer ratio and their interaction had a significant impact on crop water consumption,water and precipitation utilization efficiency.TN2 treatment improved water use efficiency by 48.59%,12.71%and 9.3%,and precipitation utilization efficiency by57.13%,14.53%and 11.44%.It's the most water efficient treatment.In summary,the appropriate application method and fertilizer ratio significantly affected the growth of winter wheat and the process of water and nitrogen utilization.The TN2-treated nitrogen application model can obtain higher 1000-grain weight,water use efficiency and nitrogen use efficiency while producing higher yield.The nitrogen application mode treated by CN3 can simplify the production process by one-time fertilization while obtaining higher yield.Therefore,in the process of winter wheat production,the nitrogen application model of TN2 treatment was recommended from the perspective of thousand grain weight and water and nitrogen utilization.From the perspective of light and simplified agricultural production,the nitrogen application mode treated by CN3 is recommended,which can save labor and cost while obtaining high yield.