Study On Optimum Fertilization Technology Of P Fertilizer For Drip-Irrigated Maize In Xinjiang

[Object]Phosphorus is one of the three essential elements of crop nutrition.Adequate but not excessive phosphorus nutrition is very important to increase crop yield and high phosphorus efficiency in agriculture practice.Xinjiang is one of China's high-yield maize regions,but like many other regions in China,there are long-term problems in agricultural production such as excessive application of phosphate fertilizer and irrational fertilization structure.Through water-fertilizer coupling technology,this thesis studied different P fertilizer type,basal/topdressing ratio of phosphate fertilizer,N/P ratio and P application dose on maize growth and yield response,under drip irrigation.We also studied crop P uptake dynamic in different growth stages.The results of this study could present a systematic knowledge base for drip-irrigated maize production in Northern Xinjiang.[Method]The experiment was conducted in the experimental station of Agricultural College of Shihezi University in2017,and the Experimental Station of Agricultural Science Research Institute of the 9th Division of Xinjiang Production and Construction Corps in 2018.We studied different basal-topdressing ratios of phosphate fertilizer?base:topdressing at 1:0,1:1,1:3,and 0:1?,P fertilizer types?MAP:monoammonium phosphate;UP:urea phosphate;APP:Water-soluble Ammonium Oligophosphate?,N/P ratios?1:0.2,1:0.4and 1:0.5?on maize growth and yield.Plot exploration experiment was conducted in 2017,the tasted maize material was SC 704?Zea Mays L.SC704?.In 2018,we integrated optimal P fertilization methods in-field to test the comprehensive effects.The critical phosphorus concentration curve model and phosphorus nutrition index were studied.The tested maize variety was HeYu 187.[Result]?1?Under the condition of the identical phosphorus input,25%base fertilizer and 75%of topdressing showed best yield increase,which produced 18.05%higher yield then that of 100%base application and the recovery rate of P increased by 23.90%.The study also found that the absorption of N and P of drip-irrigated maize mainly in the late growth stage?spinning to filling stage?,and the absorption of K is mainly in the early growth stage?from jointing stage to near tassel stage stage?.?2?All the three phosphorus fertilizer type increase the available phosphorus content of soil,and available phosphorus content of APP treatment in the soil layer of 10-15 cm increased the most.Under drip irrigation conditions,all three P fertilizer had soil acidification effects,and UP treatment was the most significant.In the field experiment,the soil available phosphorus content in APP treatment was higher in deep soil,and the UP-treatment soil pH was the lowest.APP most significantly promoted maize root development,and the maize tissue has the highest phosphorus content and phosphorus absorption and the highest yield?14.40t/hm²?.?3?Under 300 kg hm^-2 N application,The N/P ratio 1:0.4 had the best effect on maize yield and economic benefit.?4?The sectional quadratic parabola fitting is suitable for the critical phosphorus concentration.If biomass<11.91 t/hm²,the P dynamic curve is:=0.0024*(2-0.0282*(2+0.4662.If biomass?11.91 t/hm²,the P dynamic curve is:=0.0005*(2-0.0382*(2+1.0128?R²=0.980,RMSE=0.071 g/kg,n-RMSE=15.3%?.Where Pc is the concentration of P in maize leave,and DW is the biomass.This model can be used to evaluate the lack of phosphorus nutrients in drip corn.?5?Compared with conventional fertilization,the optimized fertilization technology of phosphorus fertilizer with 8%reduction of nitrogen fertilizer and 24%phosphorus fertilizer has significant effect on increasing yield by integrating individual techniques and replacing diammonium phosphate as base fertilizer with starter fertilizer.The yield is 23.3 t/hm²?14%grain water content?.Compared with conventional fertilization,the yield of this technology increased by 32.1%-36.8%and the chemical fertilizer is reduced by 8%nitrogen fertilizer and 24%phosphorus fertilizer.The marginal productivity increased 13.7%-14.6%with obvious economic benefits.[Conclusion]Under drip irrigation,base:topdressing at 25%:75%and N/P at 1:0.4 were most beneficial to the accumulation of dry matter in maize,the absorption of phosphorus at the later growth stage and the formation of yield in maize in Xinjiang.P concentration in maize leave is a single peak curve with the progress of growth,and suit to fit P dynamic curve with biomass by a sectionalized parabolic curve and P nutrition index.Water-soluble ammonium polyphosphate has the best effect on soil available P,maize root development and yield.Water-soluble ammonium polyphosphate is the best fertilizer for drip-irrigation maize.Integration each single P optimization fertilization technology,combined with water-fertilizer coupling technology,on the base of reducing the input of fertilizer by 17%?24%of P and 8%of N?,maize yield increased more than 30%,achieving the goal of fertilizer-saving and high P efficiency.