Manure management

Manure from animal livestock generally contains residual carbon, nitrogen and other substances. During its storage in or outside the stall as well as its application methane and nitrous substances such as N2O, ammonia, and nitrogen gas are emitted. The extent depends on a range of factors which include animal category, feed composition, but also the manure management type such as liquid or solid handling. Methane is produced from manure in an amount which depends on the concentration of organic residues in the manure. Of nitrogen a portion is excreted into the manure as a consequence of protein digestion and is converted to N2O by bacterial processes of nitrification and denitrification (for details see chapter 11.4). After measurements by Schön (1993) per cubic meter of cattle manure about 1,300 g methane and 30 gram nitrous oxide were deliberated. Both CH4 and N2O contribute to the climate effects of agriculture. In U.S. agriculture, this type of emissions amounts to a total of about 41.3 and 9.5 Mio t CO2-eq. for CH4 and N2O, respectively (EPA, 2007b) or about 10 percent of the total emissions in agriculture.

There is a range of technologies applied to prevent such emissions, including separation of solid components of manure, aeration, anaerobic biogas fermentation of manure or coverage with straw. As is indicated by figure 11.1 the best results are achieved through biogas fermentation where emission is 60 percent lower compared to untreated manure. The coverage with straw results in even higher emissions.

140 -,

c

o

o

120

CL

tn

100

c

o

10

80

10

o

60

O

o

40

o

20

>

re

£

0

Anaerobic Separation of Aeration Coverage with digestion solids straw

Figure 11.1 Relative GHG from selected manure treatment technologies

Was this article helpful?

0 0
Organic Gardeners Composting

Organic Gardeners Composting

Have you always wanted to grow your own vegetables but didn't know what to do? Here are the best tips on how to become a true and envied organic gardner.

Get My Free Ebook


Post a comment