Effect Of Urea With UAN Under Shallow Buried Drip Irrigation On Spring Maize Production And Nitrogen Efficiency

In 2019,The experiment was carried out in the Agricultural High-tech Demonstration Park in Horqin District,Tongliao City,Inner Mongolia.Using Nonghua 101 as a test variety,with conventional fertilization as CK1 and non-nitrogen application as CK2,studied the effects of urea reduction with UAN(Urea Ammonium Nitrate)under shallow-buried drip irrigation(indicated as 225kg/hm2urea+75kg/hm2UAN?225kg/hm2urea+150kg/hm2UAN?375kg/hm2 urea+75kg/hm2UAN?375kg/hm2 urea+150kg/hm2UAN;respectively abbreviated as N1U1?N1U2?N2U1?N2U2),on root and shoot physiological characteristics,material production,nitrogen use,and nitrogen distribution in the root layer of spring maize populations in the West Liaohe Plain.The main test results are as follows:1.N2U2,N1U2 and N2U1 of the net photosynthetic rate,SPAD value in milking and chlorophyll density of spring maize population were significantly higher than CK1,there were no significant difference between other treatments.2.N2U2,N1U2 and N2U1 of dry matter accumulation of various organs,dry matter accumulation rate before silking,dry matter transshipment volume,dry mattertrans matter transfer rate and contribution of transport amount to grain of spring maize were all significantly higher than CK1,and there were no significant difference among other treatments.These showed that urea with appropriate amount of UAN could promote more assimilation of corn stalk,sheath and leaves to grain.3.N2U2,N1U2,N2U1 of nitrogen accumulation of spring maize population,nitrogen accumulation rate before silking,nitrogen transportation,stalk sheath nitrogen transport rate and contribution rate of transport amount to grain were significantly higher than CK1.Agronomic efficiency of nitrogen fertilizer and nitrogen fertilizer partial productivity of urea with UAN processing were significantly higher than CK1,nitrogen uptake efficiency of urea with UAN processing were significantly higher than CK1,nitrogen fertilizer contribution rate of N2U2 and N1U2 were significantly higher than CK1,N1U1.Urea with appropriate amount of UAN can effectively improve the nitrogen fertilizer efficiency of spring maize and reduce the ineffective loss of nitrogen.4.N2U2,N1U2 and N2U1 of spring maize root dry weight,SOD activity in roots,POD activity in each period were significantly higher than other treatments.It showed that compared with conventional urea application,the urea with appropriate amount of UAN were more beneficial to root growth and enhance the anti-aging ability of maize root.5.N2U2,N1U2 treatments of spring maize ear length,ear thickness,thousand kernel weight and yield were all significantly higher than N1U1,CK1 and CK2.Except N1U1,the economic benefits of each treatment of urea with UAN are higher than CK1 and CK2,among them,the yield and economic benefits of N2U2 have reached the highest.The yield of N2U2 was 13.82t/hm2,it increased by 5.5%and 72.5%compared to CK1 and CK2;the economic benefit of N2U2 was 18,854.77 yuan/hm2,compare with CK1 and CK2,it increased by 858.72 yuan/hm2 and 9,394.81 yuan/hm2 respectively.The increase rates were 4.8%and 99.3%respectively6.Alkali hydrolyzable nitrogen content in each soil layer,soil nitrate nitrogen content in different period were performed CK1 significantly higher than other treatments,CK1 of soil ammonium nitrogen content in each period were significantly higher than other treatments.Urea with UAN treatments of Nitrogen content in root soil were significantly lower conventional urea application.The content of alkali-hydrolyzed nitrogen of CK1 at 0?20cm during silking was 44.6%and 74.1%higher than N1U2 and N1U1;the content of ammonium nitrogen of CK1 at 0?20cm during silking was 27.3%and 60.9%higher than N1U2 and N1U1;the content of nitrate nitrogen of CK1 at 0?20cm during silking was 57.6%and 89.5%higher than N1U2 and N1U1.It showed that the use of UAN can promote the utilization of nitrogen sources in the root soil by maize root system.Under the condition of integrated irrigation of water and fertilizer for spring maize shallow burial drip irrigation in the West Liaohe Plain,topdressing urea 375kg/hm2 with UAN 150kg/hm2 treatment combination can further improve the nitrogen absorption efficiency of spring maize and reduce nitrogen loss.It was a suitable ratio of nitrogen fertilizer topdressing of spring maize shallow-buried drip irrigation integrated with water and fertilizer to reduce nitrogen and increase efficiency in the West Liaohe Plain irrigation area.