Development Of Effectively Urea Ammonium Nitrate Fertilizer And Its Application In Soda Saline-alkali Soil

Soda saline-alkali soil is a kind of stabilized soil with strong alkalinity,poor water permeability and poor physical and chemical properties.The nitrogen fertilizer applied to soda saline-alkali soil is easy to lose in the form of ammonia volatilization and nitrous oxide emission.Tongyu County in the west of Jilin Province is a typical arable soda-saline-alkali soil area.Maize is the main food crop in the area.Maize is a salt-sensitive crop,and soil salinization will limit the potential of maize yield increase.In 2018,the average corn yield in the western part of Jilin Province was 6.65×10~3 kg/hm~2,but in the same year,the average corn yield in Tongyu County was only 3.29×10~3 kg/hm~2,less than half of the average corn yield in the western part of Jilin Province,which seriously restricted the local corn production and economic development.To reduce the nitrogen loss caused by ammonia volatilization and nitrous oxide emission of nitrogen fertilizer in soda saline-alkali soil and reduce the impact of soil salinization on maize production.This paper takes urea ammonium nitrate solution(UAN)and nitrogen fertilizer synergist as research objects,and the"Effectively urea ammonium nitrate fertilizer(Eff UAN)"suitable for soda saline-alkali soil was developed with the application of laboratory preparation methods.The main research findings are as follows:1.Development of Effectively urea ammonium nitrate fertilizer.Two kinds of enhanced liquid nitrogen fertilizer with good stability were developed by orthogonal experimental design and laboratory preparation methods,which were the enhanced liquid nitrogen fertilizer?type(Eff UAN?)and the enhanced liquid nitrogen fertilizer(Eff UAN?).Both kinds of fertilizers were acidic with p H=5.Among them,Eff UAN?total nitrogen content?375 g/L,nitrate nitrogen?94 g/L,ammonium nitrogen?94 g/L,amide nitrogen?87 g/L,phosphorus pentoxide?1 g/L.Eff UAN?Total nitrogen content?375 g/L,nitrate nitrogen?94 g/L,ammonium nitrogen?94 g/L,amide nitrogen?87 g/L,sulfur?5 g/L.2.Effectively urea ammonium nitrate fertilizer reduces ammonia volatilization and accumulated nitrous oxide emissions.The results of soil culture experiment showed that compared with Urea treatment,Eff UAN?and Eff UAN?can reduce the accumulation of ammonia volatilization by 73.7%and 74.3%,and the accumulation emission of nitrous oxide by29.2%and 30.0%.Compared with UAN treatment,Eff UAN?and Eff UAN?can reduce the accumulation of ammonia volatilization by 40.2%and 41.5%,and reduce the accumulation emission of nitrous oxide by 26.3%and 27.0%.3.Effectively urea ammonium nitrate fertilizer promoted the growth and development of maize.The pot experiment showed that compared with Urea treatment,Eff UAN?and Eff UAN?can reduce soil p H by 1.02 and 1.03 units on average.At the jointing stage of maize,the root length density increased by 115.6%and 109.0%at the depth of 21-28 cm underground.Aboveground biomass increased by 12.7%and 12.0%at maturity stage.Compared with UAN treatment,Eff UAN?and Eff UAN?can decrease soil p H by 1.04 and 1.05 units on average,and increase root length density by 46.2%and 56.2%on average at 21?28 cm underground in maize jointing stage.Aboveground biomass of maize increased by 8.3%and 8.2%on average at maturity stage.4.Effectively,urea ammonium nitrate fertilizer increased maize yield and improved nitrogen use efficiency.Under drip irrigation and fertilization,compared with D-UAN and D-UAN,D-Eff UAN could increase yield by 9.8%and 9.1%,and N use efficiency by 18.9 and9.16 percentage points.Compared with C-UAN and C-UAN,C-Eff UAN could increase yield by 18.5%and 13.8%,and N use efficiency by 16.6 and 7.07 percentage points under conventional fertilization.