Emissions of ammonia, nitrous oxide and methane from different types of dairy manure during storage as affected by dietary protein content

Abstract

In a storage experiment with dairy cow manure, the effects of dietary protein content and manure type on ammonia, nitrous oxide and methane volatilization as well as overall nitrogen (N) loss from manure were investigated. Early-lactating cows received rations with 175, 150 and 125 g crude protein\kg dry matter. Each ration was tested in four manure storage systems reflecting typical farm conditions. These either contained total excreta with high amounts of straw (deep litter manure) or no straw (slurry) or, proportionately, 0n9 of urine and 0n1 of faeces (urine-rich slurry) complemented by the residuals with a low amount of straw (farmyard manure). Manure samples were stored for 7 weeks under controlled conditions and trace gas emission was repeatedly measured. Reduction of N intake decreased daily N excretion and urine N proportion and, on average, led to 0n7-fold lower storage ammonia emission rates on average. Total storage N loss was simultaneously reduced with the extent depending on urine N proportion of the respective manures. A lower dietary protein content furthermore reduced nitrous oxide emission rates in most manure types but increased methane emission from urine-rich slurry ; however, global warming potential (based on trace gas output) of all manures was similar with low and high dietary protein content. In deep litter manure, characterized by the highest C : N ratio, emission rates of total N, ammonia and methane were lowest, whereas nitrous oxide values were intermediate. Substantial emission of nitrous oxide occurred with farmyard manure which also had the highest methane values and, consequently, by far the highest global warming potential. C : N ratio of manure was shown to be suitable to predict total N loss from manure during storage in all manure types whereas urine N proportion and manure pH were only of use with liquid manures.

Enteric and manure-derived methane and nitrogen emissions as well as metabolic energy losses in cows fed balanced diets based on maize, barley or grass hay

“…The C : N ratios found in fresh slurry in this study were rather low compared with other studies (e.g. Kü lling et al, 2001 and2002;Hindrichsen et al, 2006) due to notably high slurry-N contents. However, similar C : N ratios were found in the study of Kü lling et al (2003).…”

Effect of the tropical tannin-rich shrub legumes Calliandra calothyrsus and Flemingia macrophylla on methane emission and nitrogen and energy balance in growing lambs

“…The shift in the excretion of N from urine to faeces as a result of feeding CT-rich legumes is still of practical relevance because the ratio of urinary N to faecal N determines the level of gaseous ammonia losses (Kü lling et al, 2001). The potential of CT to significantly decrease ammonia N emission from the animal's excreta was demonstrated by Ś liwiń ski et al (2004).…”

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

“…Urea and other metabolic byproducts are then extracted from the bloodstream by the kidneys before they are excreted via the urine (Hill et al 2008). Therefore, a large amount of the nitrogen in livestock manure slurry is derived from urinary urea (Canh et al 1997;Dai and Karring 2014;Kulling et al 2001). Urea is also produced industrially by the Bosch-Meiser urea process (Bosch and Meiser 1922), and both urine-derived (manure slurry) and synthetically produced urea are extensively used as fertilizers.…”