Effects Of Different Temperature Biochar-manure Compost On Greenhouse Gases Emission In Upland Red Soil

Aiming at the current situation of strong red soil,low fertility and relatively low productivity in the red soil of southern China,the application of biomass carbon-organic fertilizer compost（biomass charcoal as compost filler）to the red soil in the dryland,exploring the biomass carbon-organic fertilizer The role of composting in greenhouse gas emission reduction and soil nutrient retention in red soil in dryland has potential practical value and broad application prospects.In view of the large influence of temperature on the properties of biomass charcoal,this experiment was carried out in the form of indoor culture test to explore the effects of different temperature biomass carbon-organic compost on greenhouse gas emissions from dryland red soil.The experimental design is as follows:Experiment 1:fresh soil（CK）,fresh soil+biomass charcoal（B1）prepared at 300°C,fresh soil+biomass charcoal（B2）prepared at 550°C,fresh soil+biomass prepared at 800°C Carbon（B3）;Experiment 2:Biomass carbon-organic fertilizer compost（B1M）prepared in fresh soil+300°C,biomass carbon-organic compost（B2M）prepared in fresh soil+550°C,fresh soil+800°C Biomass carbon-organic fertilizer compost（B3M）,fresh soil+organic fertilizer compost（M）.The main findings are as follows:1.The effect of biochar on the greenhouse gas emission of red soil in dryland was significantly different due to different preparation temperatures.The cumulative emission of N2O in B2 treatment was the lowest in 30d,which was significantly lower than that of CK by 8.54%.The cumulative emission of CH4 in each treatment was not significant.Difference;compared with CK,the cumulative emissions of B1 treatment increased by 4.77%,B2 and B3 treatment decreased by 7.95%and 5.09%respectively;overall,B2 treatment greenhouse gas warming potential（GWP）was the lowest,with CK Compared to the significant reduction of 8.21%.The addition of biomass charcoal to the organic fertilizer compost can reduce the greenhouse gas emission of red soil in dryland,and with the increase of biomass carbon preparation temperature,the cumulative emissions of N₂O and CH₄ are increasing,and the cumulative emission of CO₂ is opposite.Compared with M,the cumulative emissions of N₂O,CH₄ and CO₂ treated by B1M,B2M and B3M decreased by 11.9%¹7.8%,-4.51%³.44%and 38.53%⁴8.91%respectively;but B1M,B2M,B3M There was no significant difference in greenhouse gas warming potential（GWP）between treatments,which was 20.98%²3.39%lower than M treatment.2.The addition of biochar significantly improved the physical and chemical properties of red soil in dryland,and the pH,organic carbon,total nitrogen and C/N of dryland red soil increased with the increase of biomass carbon preparation temperature.Compared with CK,the pH,organic carbon content and total nitrogen content of red soil in B1,B2 and B3treatment increased by 4.16%¹5.83%,43.42%¹09.4%,13.08%¹7.75%and27.19%⁷7.49%,respectively.Compared with M,the pH,organic carbon content and total nitrogen content of red soil in B1M,B2M and B3M treatment increased by 1.88%¹7.54%,14.32%³6.63%,4.37%¹0.21%and 2.14%⁴0.30%,respectively.3.The addition of biochar increased the activity of amylase,sucrase and urease in red soil in dryland.The biomass carbon prepared at low temperature had more obvious effects on amylase and sucrase.The biomass carbon prepared at high temperature increased the urease more.The cumulative activity of B1 treatment of amylase and sucrase was the highest in 120d,but the cumulative activity of urease in B3 treatment was the highest,which increased by 16.15%,10.08%and 7.21%,respectively,compared with CK.The addition of biomass charcoal to composting is less effective than amylase,sucrase and urease alone.Biomass carbon-organic fertilizer composting increased the cumulative activity of amylase and sucrase with the increase of biomass carbon preparation temperature,and urease showed the opposite law.4.The effects of biomass charcoal on microbial biomass at different preparation temperatures are also different.The specific performance of biomass charcoal prepared at low temperature is more obvious for the promotion of bacteria and fungi,and with the increase of temperature,AOA and AOB genes As the copy number increases,the copy number of the nirK and nirS genes decreases.The application of organic fertilizer compost significantly increased the soil microbial biomass.The amount of microbial biomass in the organic fertilizer compost was decreased,and the difference in biomass carbon-organic compost between different temperatures was not obvious.In conclusion,the application of biomass charcoal to dryland red soil can reduce the greenhouse gas emissions of red soil in dryland,affect soil invertase,amylase,urease activity and microbial biomass.Adding different temperature biochars to organic fertilizer composting into dryland red soil has obvious effects on greenhouse gas emission reduction,but there is no significant difference between biomass biochar composts at different temperatures.