Effect Of Chemical Fertilizer Reduction Combined Organic Fertilizer On Rice Growth And Gas Regulation Value In Paddy Field

In order to ensure high yield and stable production,large amounts of chemical fertilizer are applied to paddy fields,a result of excessive fertilization and environmental pollution,which cannot be ignored.Hence,it is an inevitable trend of modern agricultural development to choose scientific and reasonable fertilization measures to achieve a win-win situation between economic and environmental benefits in paddy fields.Previous studies show that reducing chemical fertilizers and combining organic fertilizers could increase the rice yield,However,there`s not enough data to support whether the long-term application of organic fertilizer could improve the economic efficiency while balancing environmental benefits.Therefore,this experiment was conducted at the long-term location fertilization base,Hunan Liuyang,through the method in-situ monitoring of field,In accordance with the local design,set six different treatments including the reducing of chemical fertilizers combined fresh pig manure?PF?,biogas slurry biogas residue?BF?,pig manure compost?DF?,and Astragalus sinicus L.or rice straw?GF?,conventional application of chemical fertilizer?CF?and none nitrogen fertilization?WN?,research under the condition of different fertilization with the influence on early rice and late season rice yield?biomass and CH₄,CO₂,N₂O emissions,calculated the global warming potential and estimated the values of greenhouse gas emissions,the capacity of carbon fixation and oxygen release in paddy fields by the afforestation cost method and industrial oxygen production method.Comparing the differences in the amount of gas regulation value in paddy fields under different fertilization conditions.In order to provide a theoretical reference for the scientific evaluation of the economic efficiency and environmental benefits of chemical fertilizers with different types of organic fertilizers.The main conclusions are as follows:1.The application of organic fertilizer increased rice yield and improved yield component factors.Compared with CF,the rice yield of combined with organic manure treatment increased between 1.16%?11.1%.It also increased the effective panicles per unit area,grain number per panicle,and seed setting rate,but the 1000-grain weight of rice was reduced.In the treatment of organic fertilizers,the yield of DF was the best.2.The application of organic fertilizer increased the emissions of CH₄ and CO₂,and at the same time it reduced N₂O emissions.The cumulative emissions of CH₄ trend was PF>BF>GF>DF>WN>CF,theorderofthecumulativeCO₂emissionswas PF>BF>DF>GF>CF>WN,while the cumulative N₂O emissions is GF>BF>CF>PF>DF>WN.Compared with CF,only CH₄ and CO₂ accumulative emissions of PF reached a significant difference?P<0.05?,while PF and DF reduced N₂O emissions by 4.49%and 8.15%respectively,but there was no significant difference from CF.3.The application of organic fertilizers has increased the warming effect of paddy fields and reduced the intensity of greenhouse gas emissions.The warming effect of each organic fertilizer application has been increased between 8.53%and 55.5%,but after comprehensive consideration of the effect of temperature increase?greenhouse gas emission intensity?per unit output,it was expressed as PF>BF>WN>GF>CF>DF,where DF was the largest reduction compared with CF,with a decrease of 2.21%.4.The application of organic fertilizer enhances the gas regulation function of the paddy ecosystem.After the valuation of the gas regulation function was performed,the positive value of carbon fixation and oxygen release was increased after the application of organic fertilizer in paddy fields.The increment was between 1622.3?/ha?2922.3?/ha,but it also increased the emission of greenhouse gases.The negative value is between 1035.2?/ha?6706.5?/ha.After calculating the total value of the total value,the order was DF>BF>GF>CF>PF>WN,thereinto DF is the highest,which is 1296.2?/ha higher than that of the CF.In summary,considering the impact of organic fertilizers on CH₄,CO₂ and N₂O emissions from paddy fields,and the combined effects of carbon sequestration and oxygen release in paddy fields,pig manure composting is a more scientific and rational fertilizer application measure in this experiment.