Control of gaseous emissions of ammonia and hydrogen sulphide from cow manure by use of natural materials

Abstract

Winter management practices involving the use of stand-off pads to reduce problems due to cows grazing on wet soils may require storage of cow manure for extended periods prior to field application. Gaseous losses of nitrogen (N) and sulphur (S) from stored cow manure can be considerable, and these gases are offensive and undesirable. Laboratory incubation studies were conducted to measure gaseous loss of ammonia (NH 3 ) and hydrogen sulphide (H 2 S) from stored cow manure under aerobic and anaerobic conditions. The potential of adding a range of natural materials, including soil, untreated pine bark, sawdust and wood savings, to the manure to reduce these gaseous emissions was investigated. Aerobic incubation of manure resulted in a higher emission of NH 3 than anaerobic incubation, while anaerobic incubation resulted in higher emissions of H 2 S. The effectiveness of natural materials in reducing losses of NH 3 was investigated under anaerobic conditions, and pine bark was found to be the most effective. However, all materials reduced NH 3 to some degree. Therefore, the addition of natural materials, such as pine bark and soil, as amendments to cow manure during storage offers potential for reducing emissions of NH 3 and H 2 S.

A test of a winter farm management option for mitigating nitrous oxide emissions from a dairy farm

“…As the stocking rate was three cows per hectare on this grazed pasture, the stand‐off pad itself could contribute about 0.01 kg N 2 O‐N per hectare of grazed pasture to the total emissions associated with the whole farm system. The immobilization of cow excreta N in the wood materials in the pad because of the high C/N ratios of pine bark and sawdust (Luo et al. , 2004) probably caused the initial very low N 2 O emission rates when the cows started to use the pad.…”

Effects of irrigating dairy-grazed grassland with farm dairy effluent on nitrous oxide emissions

“…Therefore, delaying FDE-irrigation after a grazing event could further reduce N 2 O emissions by reducing the levels of surplus mineral-N. However, gaseous emissions from FDE during storage need to be controlled (Luo et al 2004a).…”

Sawdust and bark to treat nitrogen and faecal bacteria in winter stand‐off pads on a dairy farm

“…Ammonium ions, either hydrolysed or mineralised from cows' excreta, can adsorb onto cation exchange surfaces, therefore decreasing the quantity of dissolved ammonium ions and the quantity of equilibrated NH 3 gas available for ammonia volatilisation. This was demonstrated by lower NH 3 volatilisation losses from bark-and sawdust-amended cow manure than unamended manure (Luo et al 2004). Sorption of odorous compounds, including NH 3 gas, by pine bark has also been found to be one of the important mechanisms in removal of odours by biofilters containing bark .…”

“…There are literature reports of the effectiveness of some materials with potential for use in stand-off pads (Bolan et al 2004;Luo et al 2004;Misselbrook & Powell 2005;Vinten et al 2006;Luo & Saggar 2008). in a study in which cow manure was mixed with pine bark, it was found that the bark retained N and reduced gaseous losses including ammonia (NH 3 ) and hydrogen sulphide (H 2 S) (Luo et al 2004). These workers considered that the retention of N may have been due to adsorption and/or immobilisation of N and sulphur by the C-rich bark.…”