Greenhouse Gases Emission In Different Pig Rearing Modes

With the development of livestock production, intensive and large-scale was continuously improved, greenhouse gases emissions of livestock breeding has caused great concern. Pig industry is one of the main sources of livestock greenhouse gas. Therefore, to evaluate greenhouse gas emission of the different pig breeding model and the effect of related factors and investigate nitrogen transformation in the fermentation bed have important scientific significance, which help reduce greenhouse gases emissions by taking reasonable measures and reduce the risk of contamination on the ecological environment in practical pig production. According to the carbon balance method principle, fluxes of greenhouse gas emissions from different barn were estimated, and to analyze the factors of greenhouse gas emissions of fermentation bed, in Liuhe, Nanjing. And to investigate the change of different nutrient forms in litters, the different nitrogen forms, TOC, C/N ratio, water content, pH were determined in bedding(0-20cm,20-40cm), and simultaneous determinate the emissions of N2O and NH3 by static chamber method. The main conclusions are as follows:(1) The average CH4, CO2 and N2O concentration in fermentation bed was 1.59,893.95,1.00 mg·m-3, which was 61.2%,78.6% and 125.0%of traditional barn, respectively.(2) The emissions of CH4 first increased and then decreased. CH4 emission from pig house varied between 122.48-162.09mg-(h·pig)-1 or 711.27-1199.75 mg-(h-AU)-1. Compared with traditional barn, the average CH4 flux of fermentation bed was 63.6% lower than the traditional barn, while N2O and CO2 was 10 times and 1.4 times higher.(3) Taking into account the traditional farm manure composting and swine lagoon in the course of the follow-up management also emit large quantities of greenhouse gases. The total greenhouse gases emissions per day per pig in CO2 equivalent from fermented bed was 26.3% more than the traditional farm during the experiment, and CO2 was the main contributor to the total greenhouse gas emissions during fermentation bed pig raising, N2O was followed.(4) By correlation analysis, organic matter is a major factor in the impact of methane emissions (r=0.949, P<0.05), the higher content of organic matter, the greater potential methane emissions.(5) The content of TN, NO3--N, alkali-hydrolyzed nitrogen in the layer of litters tended to increase, while NH4+-N increased at first, and then decreased, declined in general. The content of TN, NO3--N, alkali-hydrolyzed nitrogen and NH4+-N of the test at the end in bedding was 111.23%,144.02%,126.35%,89.0% of the beginning, respectively.(6) The emissions of N2O and NH3 volatilization first increased and then decreased, gaseous emissions were, respectively,3.59 kg for N2O,1.69 kg for NH3 during the test.