Study On Holstein Dairy Cow Dung CH₄, CO₂&NH₃Emission By Natural Fermentation In Different Seasons

Test using the portable gas detector on the Holstein dairy cow dung in the spring, summer, autumn andwinter outdoor natural fermentation conditions of CH₄, CO₂and NH₃30-day emission, draw30-dayemission of the four seasons change curve and analyze significant of the differences between the seasons,also analyze the temperature and the daily emission of these gases by linear correlation. The results showedthat: the per ton Holstein dairy cow dung in the natural fermentation conditions, CH₄30-day total release ofthe four seasons of spring, summer, autumn and winter, respectively210.79,450.04,168.94and119.45g;CO₂respectively release8428.80,27127.45,5147.29, and1206.61g in30-day; NH₃respectively release56.52g,141.81,35.67and13.38g in30-day. Because of the seasonal average temperature are different,CH₄, CO₂and NH₃30-day emission are not the same, each season different gases emission changes andseasonal temperature changes are consistent: summer> spring> autumn> winter. Each season CH₄, CO₂andNH₃30-day release changes with the average temperature of the test period was a positive linearcorrelation, but the the summer cow dung in NH₃after17-day emission peak of its release graduallydecreased. Although the average winter temperature is-7.25℃, but the cow dung still release alittle CH₄,CO₂and NH₃. Except between spring and autumn, autumn and winter, the rest of the season CH₄emissionsignificantly （P<0.05）. No significant difference （P>0.05） in addition to the the spring30-day with autumn30-day between CO₂emission, the rest of the season30-day of CO₂emission differences were significant（P<0.05）, in which the spring with summer and winter between, summer with autumn and winter, thedifference was highly significant （P<0.01）. The difference was not significant （P>0.05） in addition to theNH₃emission between autumn30-day with spring and winter, the rest of the season30-day NH₃emissiondifferences were highly significant （P<0.01）. The spring CO₂emissions than autumn the rate of increase ismuch higher than the magnitude of the increase in CH₄emissions.