Effects Of Tillage Modes And New Nitrogen Fertilizers On Ammonia Volatilization And N₂O Emissions In The Soil-crop System

Exploring a green agricultural development path that is coordinated with high crop yields,resource efficiency and environmental friendliness is an urgent need to ensure national food security and resource and environmental security.Nitrogen fertilizer,as an important means of production,had made outstanding contributions to increasing corn yield.By regulating the type of nitrogen fertilizer,it was possible to improve the utilization efficiency of nitrogen fertilizer by corn,reduced the loss of active nitrogen in the soil-crop system,and achieved the synergy of high yield,high nutrient efficiency and environmental safety.The soil tillage mode had an important influence on the effect of nitrogen fertilizer application.In order to further clarify the regulation mechanism of new nitrogen fertilizers on field corn yield and soil-crop system reactive nitrogen emission under different soil tillage modes,a three-year(2018-2020)fixed-point experiment was passed under two soil tillage modes in Lishu County,Jilin Province.The effects of nitrogen fertilizer types on maize yield and the characteristics of active nitrogen emission from the soil-crop system were studied.The main findings are as follows:(1)The tillage mode significantly affected the soil temperature of 0-5 cm soil layer and the soil water content of 0-60 cm soil layer during the key growth period of maize.Compared with the rotary tillage mode,the soil temperature in the 0-5 cm soil layer at the maize seedling and jointing stage of the strip tillage mode decreased by 1.8?and 1.4?,respectively,and the soil temperature of the 0-5 cm soil layer increased by 1.4?and 1.6?during the silking and filling stage,respectively.The strip tillage mode increased the soil moisture content in the jointing,silking,filling and maturity stages of corn,increasing by 3.1%,2.4%,1.7%,and 1.7%,respectively.(2)Under the condition of one-time fertilization,tillage mode and nitrogen fertilizer type significantly affected corn grain yield and corn nitrogen absorption and utilization.Maize grain yield,plant nitrogen uptake and nitrogen use efficiency at maturity stage were 8881 kg hm^-2,121.2kg hm^-2 and 35.5%under strip tillage mode,which were significantly lower than those of rotary tillage mode(9342 kg hm^-2,9342 kg hm^-2,130.6 kg hm^-2 and 45.5%);Compared with conventional nitrogen fertilizers(U),the tested new nitrogen fertilizers significantly increased maize grain yield and increased maize nitrogen absorption and utilization,with a yield increase of 43.0%?46.5%,the nitrogen uptake by plants in the mature period of maize increased by36.5%?40.2%,and the nitrogen utilization efficiency increased by 21.6%?23.6%.(3)Tillage modes and new nitrogen fertilizers significantly affected the soil ammonia volatilization and nitrous oxide emissions.Among them,the cumulative amount of ammonia volatilization and the total emission of nitrous oxide in the soil strip cultivation mode were 19.1kg hm^-2 and 967.1 g N₂O-N hm^-2,respectively,which were significantly higher than those in the rotary cultivation mode(17.5 kg hm^-2 and 886.6 g N₂O-N hm^-2);Compared with conventional nitrogen fertilizers(U),the tested new nitrogen fertilizers significantly reduced the cumulative amount of ammonia volatilization and the total emissions of nitrous oxide by 34.6%?41.2%and19.2%?29.0%,respectively.Among them,resin-coated urea(RCU)had a good ammonia emission reduction effect,and the addition of nitrification inhibitor(DMPP)urea had a good nitrous oxide emission reduction effect.In summary,compared with the rotary tillage mode,the stripe tillage mode reduces the soil temperature of 0-5 cm soil layer in the maize seedling and jointing stages and increases the soil moisture content of 0-60cm soil layer;and it increased the ammonia emission and nitrous oxide emission of the corn planting system,reduced the plant's absorption and utilization of nitrogen and corn grain yield,but did not affect the production increase and gaseous nitrogen reduction effect of the new nitrogen fertilizer under the condition of one-time application.