不同地面形式自然通风奶牛舍冬季温室气体和氨气排放量

Greenhouse gas and ammonia emissions of naturally ventilated cowsheds with different floor types in winter

研究不同地面形式对我国自然通风奶牛舍气体排放量的影响。选取河南省郑州市中荷奶牛培训中心2个典型的带有放牧场自然通风奶牛舍,牛舍地面分别为漏缝地板和实体地面,使用CO2平衡法计算通风换气量,同时测试分析舍内冬季温室气体和NH3的排放量。结果表明:1)采用改进的CO2平衡法计算的自然通风牛舍通风量与奶牛的生产阶段有关;2)漏缝地板牛舍内CO2、N2O、NH3和CH4的质量浓度均显著高于实体地面牛舍(P<0.05),2栋奶牛舍内CO2和CH4浓度存在一定的正相关关系(R2=0.37~0.65);3)漏缝地板牛舍的NH3和CH4排放量显著高于实体地面牛舍(P<0.05),其NH3排放量分别为19.83和11.45 g/(HPU·d),CH4排放量为117.22和32.66 g/(HPU·d)。漏缝地板牛舍的N2O排放量和实体地面牛舍无显著差异,其排放量分别为0.12和0.11 g/(HPU·d);4)温度可以显著影响舍内NH3排放量,舍内温度与氨气的排放量呈现正相关关系(R2=0.76)。实体地面奶牛舍内温室气体和NH3的浓度和排放量均低于漏缝地板奶牛舍,主要原因是实体地面的清粪次数明显高于漏缝地板。因此,漏缝地板牛舍需要增加粪坑中粪尿的清除次数,以此降低舍内有害气体的浓度和排放量。

To study the effect of different ground forms on gas emission rates of natural ventilation dairy houses in China,2 typical naturally ventilated dairy buildings were elected as tested house(slatted floor cowshed and solid floor cowshed)in China-Dutch dairy training center,Zhengzhou,Henan Province.The concentrations and emission rates of greenhouse gas(GHG)and NH3 were monitored and analyzed.The results showed that:1)The ventilation rates of natural ventilation cowsheds calculated by CO2 balance method were related to the production stage of cows.2)The mass concentrations of CO2,N2O,NH3 and CH4 of slatted floor cowshed were significantly higher than those of solid floor cowshed(P<0.05).Meanwhile,there was a strong positive correlation between the mass concentration of CO2 and CH4 in the 2 dairy buildings(R2=0.37-0.65).3)The emission rates of NH3 and CH4 of slatted floor cowshed were significantly higher than those of solid floor cowshed.The emission rate of NH3 in slatted floor cowshed and solid floor cowshed were 19.83 and 11.45 g/(HPU·d)and the emission rates of CH4 were 117.22 and 32.66 g/(HPU·d),respectively.There is no significantly difference of the emission rate of N2O between slatted floor cowshed(0.12 g/(HPU·d))and solid floor cowshed(0.11 g/(HPU·d)).4)Temperature significantly affected the NH3 emission rate in the cowshed,which was positively correlated with ammonia emission(R2=0.76).In short,the concentration and emission rate of GHG and NH3 in the solid floor cowshed were lower than those in the slatted floor cowshed.It was mainly because the feces cleaning times on solid floor were significantly higher than those in the slatted floor.Therefore,the slatted floor dairy cowshed needs to be improved to increase the removal times of feces and urine in the manure pit and reduce the concentration and emission rate of harmful gas in the cowshed.