养殖场粪污堆存中3种氨挥发测定技术比较研究

Comparison of three methods for measuring ammonia volatilization from manure storage

养殖场粪污堆放存储中的氨挥发损失是粪肥N素养分损失的重要环节。采取控氨措施能够降低粪污堆存过程中的氨排放、保存粪肥养分。从现有的可用于测定粪污堆存过程氨挥发的技术中筛选出简单易行且可靠的技术手段可为我国养殖场氨排放测定技术标准的完善提供重要依据。本研究采用通气法(VCT)、间歇式密闭室抽气法(DCT)和被动采样法(PST)同步测定牛粪堆存过程中未经处理、表面覆盖(醋糟、CZ)及施用外源添加剂(磷酸二氢钾+氯化镁、TJ)的氨挥发特征及排放通量。结果表明:(1)试验期间VCT、PST测定的氨挥发总量均低于DCT测定结果。VCT法下CK、CZ和TJ处理的氨挥发量仅为DCT法测定值的20.46%、10.09%和11.17%,而PST法下CK、CZ和TJ处理的氨挥发量为DCT法测定值的64.38%、68.64%和61.67%;(2)采用VCT、DCT、PST 3种方法测定两类减排措施的减排效果一致,覆盖醋糟(CZ)及施用外源添加剂(TJ)均可起到抑制氨挥发的作用,CZ的减排率为35.83%~70.33%,TJ的减排率为35.89%~65.01%;(3)利用PST法测定所得的氨排放量及减排率与基准方法DCT测定结果基本一致,表明PST法可作为检验农业源氨减排措施效果的测定技术,但仍需进行更多的田间验证,为后续推广提供数据支撑。

Manure storage is an important management sector in animal operations and is an important contributor to NH3 volatilization and to nitrogen loss at farm scale.Therefore,various practices for mitigating ammonia emissions from manure storage have been established to reduce the environmental pollution and to improve manure nutrients recycling.In addition,seeking simple and reliable methods for measuring ammonia volatilization of the manure storage is very important to update and complete the technical standards for the determination of ammonia emission in China’s animal farms.In this study,venting chamber technique(VCT),dynamic chamber technique(DCT)and passive sampling technique(PST)were used simultaneously to measure the ammonia emissions from manure storages under three conditions including untreated manure,surface covering(vinegar residue)and external additives application(potassium dihydrogen phosphate plus magnesium chloride).Results showed that:(1)The cumulative ammonia emissions measured by VCT and PST during the test were lower than those of DCT.The ammonia emissions of CK,CZ and TJ measured by VCT method was only 20.46%,10.09%and 11.17%of the measured values by DCT method,while the ammonia emissions of CK,CZ and TJ measued by PST method was 64.38%,68.64%and 61.67%of the measured value by DCT method;(2)VCT,DCT and PST methods all showed the significant reduction effects of the two mitigation practices,where the mitigation potentials of the CZ and TJ were 35.83%-70.33%and 35.89-65.01%,respectively,and the effectiveness of covering vinegar residue(CZ)and applying external additives(TJ)for ammonia mitigation were confirmed;(3)The mitigation potentials measured by PST method are relatively consistent with those obtained by DCT method,indicating that PST method has certain application potential as a measurement technique for evaluating the effectiveness of potential ammonia mitigation practices.However,more field verification is still needed to provide data support for subsequent promotion.