Study On Control Of Ammonia Volatilization, Greenhouse Gas Emission And Nitrogen Loss During Cow Dung Storage At Different Ambient Temperatures

Greenhouse gases（CH₄,CO₂）and ammonia（NH₃）are one of the important sources of discharge of animal and poultry manure in China.NH₃ is not only the primary odorous pollutant,but NH₃ volatilization is the main form of nitrogen loss in the process of solid stocking and composting of livestock and poultry faeces.Therefore,this study takes cow dung in Qinghai Province as the research object,through indoor simulation test,studies the greenhouse gas emissions and ammonia emission characteristics in the process of cow dung storage in different seasons and under the treatment of different improvizers,with a view to providing necessary control measures and scientific basis for the production of manure ammonia gas and greenhouse gas emissions for cattle and sheep breeding industry in the Qinghai-Tibet Plateau region.The main results are as follows:（1）The average summer temperature during the simulated storage of cow dung is19.46℃,the average humidity is 50.75%rh,the average temperature in autumn is13.83℃,the average humidity is 49.59%rh,and the average summer temperature is highest in autumn.（2）The water content during the storage of cow dung shows a decreasing trend,with an average water content of 419%t in summer,784%in autumn,and lower in summer than in autumn.The pH change showed the first slow increase and then gradually decreased,the overall is alkaline,the average of the summer pH is 8.33,the autumn pH average is 8.61,the difference between the two seasons of summer and autumn pH is not much different.（3）The total carbon content during the storage period of cow dung tends to stabilize,the average summer carbon content is 369.39 g.kg^-1,the average carbon content in autumn is 359.93 g.kg^-1;The average amount of ammonium nitrogen in summer is 0.323g.kg^-1,the average nitrogen content of nitrous is 0.028g.kg^-1,the average of ammonium nitrogen content in autumn is 0.971 g.kg^-1,and the average nitrogen content of nitrous is 0.02g.kg^-1.（4）In the process of cow dung storage,ammonia and greenhouse gases are not discharged and emission characteristics at different temperatures,and the average emission rate of NH₃ in autumn is 511.62μmol.m^-2.s^-1.The average emission rate of NH₃ in summer is 656.45μmol.m^-2.s^-1,and the average ghest emission rate of NH₃ is significantly higher in summer than in autumn.The average emission rate of CH₄ in autumn is 16.29μmol.m^-2.s^-1.The average emission rate of CH₄ in summer is94.78μmol.m^-2.s^-1,and the summer CH₄ emission rate is higher than in autumn.The average CO₂ emission rate in autumn is 6.33μmol.m^-2.s^-1 and the average CO₂emission rate in summer is 9.06μmol.m^-2.s^-1.The rate of CO₂ emissions in summer is higher than in autumn.（5）Ammonia gas and greenhouse gases vary from temperature to temperature during the storage of cow dung,with accumulated emissions of ammonia at 112.68g.m^-2 in autumn and 79.21 g.m^-2 in summer.The cumulative emissions of CH₄ in the quarter were 2.75 g.m^-2,the cumulative emissions of CH₄ in summer were 19.65g.m^-2,the cumulative emissions of CO₂ in autumn were 2.94g.m^-2,and the cumulative emissions of carbon dioxide in summer were 4.65g.m^-2.Overall,cumulative emissions of ammonia and greenhouse gases were lower in autumn than in summer.（6）NH₃ emissions and greenhouse gas emissions after adding different modifiers during the storage of cow dung at different temperatures show the following changing characteristics:Summer and autumn NH₃:In summer,the inhibition rate of each treatment compared with the blank control was:N39.54%,D19.64%,N+D51.70%,FeCl₃99.75%;the inhibition rate of each treatment in autumn compared with the blank control Respectively:N24.43%,D10.50%,N+D59.78%,FeCl₃97.79%.Summer and autumn CH₄:In summer,the inhibition rate of each treatment compared with the blank control was:N45.13%,D40.82%,N+D58.96%,FeCl₃85.51%;the inhibition rate of each treatment in autumn compared with the blank control Respectively:N61.63%,D79.31%,N+D72.13%,FeCl₃28.67%.Summer and autumn CO₂:In summer,the inhibition rate of each treatment compared with the blank control was:N39.30%,D39.84%,N+D69.53%,FeCl₃84.32%;the inhibition rate of each treatment in autumn compared with the blank control Respectively:N29.07%,D24.32%,N+D69.67%,FeCl₃52.45%.To sum up:four different inhibitors can inhibit ammonia and greenhouse gas emissions,the effects of N+D treatment and FeCl₃ treatment are the most significant.