Difference Analysis On Farmland Carbon Footprint Of Various Crop Rotation Patterns

Aricultural activities are one of the main sources of greenhouse gas emissions in the atmosphere.In this study,three different multiple cropping patterns,including wheat-corn,wheat-wheat and wheat-soybean,were used as research objects.Field trials,household surveys and laboratory analysis were combined to study no-till,tillage,and rotation.The effects of three different tillage practices on carbon emission,carbon absorption,carbon footprint,yield,economic benefit and soil nutrient dynamics of farmland in different cropping patterns were provided to provide theoretical and technical support for agricultural structural adjustment under climate change environment.The main findings are as follows:The tillage measures have significant effects on the carbon footprint of the three multiple cropping patterns.Fertilizer and irrigation are the main sources of carbon emissions under different tillage measures and multiple cropping patterns;carbon emissions per unit area of ? ? fertilizers account for 22%-34% of total carbon emissions per unit area,and carbon emissions per unit area account for total carbon emissions per unit area.60%-77%;among them,the wheat-corn multiple cropping mode has the highest carbon emission per unit area under the tillage measures,and the wheat season is the main carbon emission season,accounting for 65% of the annual total carbon emissions of the wheat-corn multiple cropping model.%;crop as the main source of carbon absorption in farmland,economic output determines carbon uptake,wheat-corn multi-cropping mode has the highest yield per unit area under the tillage and the highest carbon uptake per unit area,among which wheat The proportion of seasonal and autumn crops is 50% each;under different tillage measures and multiple cropping models,the wheat-soybean multiple cropping model has the lowest carbon footprint per unit area under no-tillage measures,and the wheat footprint per unit area is higher.And it is 2.6 times in autumn;in terms of ecological surplus,carbon footprint is negatively correlated with ecological surplus,and the area per unit area of ? ? wheat-soybean multiple cropping mode under no-tillage measures The highest surplus,with an ecological surplus per unit area of ? ? autumncrops.The tillage measures have a greater impact on the yield and economic benefits of the three multiple cropping models.Under the multiple cropping mode,the yield per unit area of wheat season was the highest under tillage measures,and the yield per unit area was the lowest under no-tillage measures.The yield of autumn crops was the main source of annual yield difference,and the wheat-corn multiple cropping mode was used for tillage.Under the measure,the output per unit area is the highest,and the output per unit area of autumn crops accounts for 50% of the annual output.In terms of economic benefits per unit area,the wheat-peanut multiple cropping model has the highest economic benefit per unit area under no-tillage measures,including autumn.The unit area of crops has the highest economic benefit,which is 1.8 times the economic benefit per unit area of wheat season and 64% of the economic benefit per unit area.Different tillage measures and different multiple cropping patterns have a greater impact on soil nutrient content in wheat season.The wheat-peanut multiple cropping pattern and the wheat-soybean multiple cropping mode and the soil nutrient content under no-tillage increased.Among them,the wheat-soybean multiple cropping mode and the wheat-peanut multiple cropping mode increased the soil total nitrogen and ammonia nitrogen content under different multiple cropping patterns.High,soil nitrate nitrogen content decreased,organic matter content increased,soil enzyme activity increased,among which wheat-soybean multiple cropping mode was the most significant;under different tillage measures,no-tillage increased soil moisture content compared with tillage and rotary tillage,Ammonia nitrogen and nitrogen content,as well as surface soil organic matter content.Considering the synergistic effect of ecological and economic benefits,wheat-peanut multiple cropping mode + no-tillage measures can reduce farmland carbon footprint,improve economic benefits,and improve soil nutrients,but no-tillage measures have lower crop yields in a certain period of time,so it can be based on actual conditions.The choice of no-tillage and other tillage measures for round farming combined with the wheat-peanut multiple cropping model.