Effect Of Different Nitrogen Application On The Formation Of Starch And Yield Of Maize With Drip Irrigation And Fertilization Integration

In this study,the grain and feed corn variety Tianci 19 is used as the research object.Using drip irrigation and fertilizer integration technology,six nitrogen fertilizer treatments were set up(AO is 0 kg·hm-2,A1 is 90 kg·hm-2,A2 is 180 kg·hm-2,A3 is 270 kg-hm-2,A4 is 360 kg·hm-2,and A5 is 450 kg·hm-2).The effects of different nitrogen levels on the biological characteristics,starch quality characteristics,and nitrogen of maize are discussed.The effects of nutrient uptake and migration,photosynthetic characteristics,and yield indicators are designed to explore the optimal nitrogen application rate for maize at the current production level,providing scientific fertilization on the premise of high yield and high quality,increasing the nitrogen fertilizer utilization rate,and thus provide efficient use of corn nitrogen fertilizer.Based on the technical support,the results are as follows:1.Suitable nitrogen application can significantly promote the growth and development of maize.Under different nitrogen treatments,the application of nitrogen at the A3(270 kg hm-2)treatment was the most favorable for the increase of leaf area and maintained a higher leaf area index during the whole growth period.At the same time,it is more conducive to increase root length density,root weight density and root volume,which is beneficial to the growth and development of whole maize plants.2.Appropriate nitrogen application can significantly increase the activity of key enzymes in starch synthesis and increase starch content in corn kernels.The application of nitrogen fertilizer increased the contents of amylose,amylopectin,total starch and key starch-forming enzymes in corn kernels to different extents.When nitrogen was applied to A3,the content of amylose,amylopectin and total starch was increased.Significantly higher than other treatments,the performance of A3>A4>A5>A2>A1>A0.The activities of ADPG-PPase,UDPG-PPase,SEB,GBSS,and SSS in grains were significantly different.The activity of APG was the highest during A3 treatment,and maintained high enzyme activity during the whole growth period,which was beneficial to increase starch accumulation rate and increase grain weight.3.Appropriate nitrogen application can significantly increase nitrogen nutrient transport in maize.With the advancement of the maize growth process,the nitrogen content of leaves and stem sheaths firstly increased and then decreased,and the grain nitrogen content gradually decreased.When nitrogen fertilizer was applied to A3 treatment,the nitrogen accumulation,metastasis and transfer rate of maize were significantly higher than other treatments,and nitrogen in stems and leaves was promoted to migrate into grains.With the increase of nitrogen application rate,corn PEP and RE gradually decreased,and AE,PE,and HI showed the maximum under A3 treatment.It shows that reasonable nitrogen application can increase the nitrogen assimilation efficiency to a certain extent and increase the nitrogen fertilizer utilization rate.4.Appropriate nitrogen application can significantly prolong the greenness of the maize leaves and increase the photosynthetic efficiency.Appropriate nitrogen fertilizer treatment can significantly increase the chlorophyll content,net photosynthetic rate,increase the photosystem ? photochemical efficiency of the functional leaves of maize,and maintain a high photosynthetic capacity during the whole growth period,indicating that appropriate amount of nitrogen fertilizer will delay aging and stabilize the photosynthetic reaction center electrons The delivery system improves the electron transfer efficiency to promote efficient energy distribution and increase photosynthetic efficiency.5.Appropriate nitrogen application significantly increased corn filling rate,extended grouting time,and improved jade yield.Under different nitrogen treatments,corn grain filling duration(T),maximum filling rate corresponding period(tmax),maximum grain growth rate(Wmax),average grain filling rate(G),and grain filling active growth period(P)There was a difference in the performance of A3 treatment,the highest yield of 17791.2 kg-hm-2.Correlation analysis showed that there was a positive correlation between yield and various indicators,indicating that a reasonable application of nitrogen can effectively regulate the intrinsic physiological changes of maize and the growth of the entire plant,which is in turn,conducive to high yields.Combining yield regression with simulation equations and economic benefits,it is recommended that the optimal nitrogen application rate in the area should be 289.5 kg·hm-2.