Effects Of Tillage And Fertilization On Soil Nitrogen Supplyand Ecological Effect Of Farmland Of Wheat--Maize Rotation In Central Of Henan Province

As one of the main areas of grain production in Henan Province,the planting pattern of winter wheat and summer maize ensured the high yield of grain in central of Henan.At present,there are many problems in this area,such as excessive use of chemical fertilizer,farmland environment quality is low and production input is high.In this study,a two-factor group design was adopted with the long-term positioning test platform for tillage and increased application of organic fertilizer,to explore the effects of different tillage and fertilization methods on soil nitrogen supply and ecological effect of farmland of wheat-maize two-year anniversary,which started in 2010.Deep tillage+organic fertilizer（DTF）,shallow tillage+organic fertilizer（STF）,no tillage+organic fertilizer（NTF）,deep tillage（DT）,shallow tillage（ST）,no tillage（NT）,deep tillage+80%nitrogen fertilizer（DTR）,shallow tillage+80%nitrogen fertilizer（STR）and no tillage+80%nitrogen fertilizer（NTR）,specifically.The following conclusions were drawn:1.Through the analysis of soil physical and chemical properties of the wheat-maize two-year anniversary,finded that add organic fertilizer can effectively improve soil moisture content and reduce soil bulk density,compared with deep tillage and shallow tillage,no-tillage significantly increased the bulk density of 0-20 cm soil layer.Under different treatments,the aggregates ratio of>0.25 was 80-90%,the proportion of<0.25 mm aggregates increased significantly under shallow tillage and organic fertilizer application.The results of soil chemical composition determination results showed that add organic fertilizer increased the content of aldehydes benzene and toluene were reduced.The cation exchange capacity of soil was increased on the treatments of add organic fertilizer,shallow tillage and no-tillage,It is beneficial to increase soil nitrogen content.2.Tillage and fertility had significant effects on soil nitrogen supply.The content of total nitrogen,nitrate nitrogen and ammonium nitrogen decreased gradually with the deepening of soil layer,add organic fertilizer significantly increased soil nitrogen content.In the 0-20 cm soil layer,The contents of total nitrogen and inorganic nitrogen in soil were high under the treatment of shallow tillage+organic fertilizer,compared with deep tillage and no tillage,In the 20-40 cm soil layer,the total nitrogen content was higher under shallow tillage,there was no significant difference in inorganic nitrogen content among different tillage treatments.In the 40-60 cm soil layer,there was no significant difference in total nitrogen content between different treatments.Through the membership function method to evaluate the nitrogen supply capacity,it was found that:soil bulk density,cation exchange capacity and total nitrogen content contributed the most to nitrogen supply capacity,which were 21%,17%and 16%,respectively,Increasing the application of organic fertilizer could effectively improve the soil nitrogen supply capacity,and the comprehensive index under shallow tillage+organic fertilizer treatment was the highest,indicating the highest nitrogen supply capacity.3.The characterized by greenhouse gas emission indicate that the Central Henan region is the"sink"absorbed by CH₄and the"source"of N₂O and CO₂.The cumulative emission fluxes of N₂O and CO₂were highest under the treatment of deep tillage and organic fertilizer.Under different treatment,the cumulative greenhouse gases emission flux was as follows:organic fertilizer>nitrogen fertilizer>80%nitrogen fertilizer;deep tillage>shallow tillage>no tillage.The warming potential was the highest under the treatment of deep tillage+organic fertilizer,which were 33069.97 kg·hm-2 and 27693.02 kg·hm-2,respectively;6.60-52.27%and 7.64-33.65%higher than other treatments;The greenhouse gases emission emission intensity was also the highest under deep tillage+organic fertilizer treatment,6.76-35.04%and5.56-19.82%higher than other treatments,respectively.Reducing tillage intensity was beneficial to reduce warming potential and improve environmental quality.4.Farming and fertilization affect soil nitrogen supply and crop yield by improving soil physical and chemical properties.Increasing the application of organic fertilizers can effectively increase crop yields,the highest annual yield was 21016.14 kg·hm^-2under shallow tillage+organic fertilizer and 20821.4 kg·hm^-2under deep tillage+organic fertilizer,respectively In 2018-2020.The total service value of farmland under shallow tillage+organic fertilizer treatment was the highest,which was 41692.93 yuan·hm-2,0.29%-8.50%higher than other treatments.Among them,the economic benefit showed that the organic fertilizer>nitrogen fertilizer>80%nitrogen fertilizer was applied.The annual input was mainly fertilizer and machinery,therefore,by reducing tillage intensity and the use of nitrogen while ensuring the amount of organic fertilizer,the ratio of input-output can be improved while obtaining higher economic value.Analysis by synthesis,soil nitrogen supply capacity,environmental and economic benefits were significantly improved under the treatment of shallow tillage+organic fertilizer,while crop yield and yield-input ratio were guaranteed.Therefore,the recommended planting mode in central of Henan should be shallow tillage+organic fertilizer.