Agriculture Reference
In-Depth Information
4.8.7 u
se
of
f
armYard
m
anures
When applied to the soil, manure is a valuable resource, as a fertilizer and soil amendment, in crop
production (Campbell et al., 1986). When applied in excessive amounts, however, manure has a
pollution potential to soil and water (McCalla and Norstadt, 1974). Of particular concern is N in its
several forms. Nitrogen found in manure can be converted into nitrate, a form that is mobile in the
soil and can be leached into groundwater. Nitrate-nitrogen, when present in excess of 10 mg kg
−1
in
drinking water, is regarded as a pollutant and a health hazard (Hendry et al., 1984). However, the
appropriate amount and method of application brings more beneficial effects of farmyard manures
in crop production without having detrimental effects on environmental pollution. Animal manures
contain a considerable amount of N, P, and K and their disposal on land for crop production may be
beneficial from the standpoint of nutrient recycling and reduced use of commercial fertilizers (Kuo
and Baker, 1982). Aoyama et al. (1999) reported that manure application contributes to the accu-
mulation of macroaggregate-protected C and N. Jenkinson et al. (1994) reported that the long-term
application of farmyard manure increases SOC considerably as was found in the classical experi-
ments over 150 years at Rothamsted in the United Kingdom. A microbial biomass is the biomass
of living and dead biomass of soil bacteria and fungi were also doubled by farmyard manure appli-
cation in the Rothamsted field trials (Jenkinson and Rayner, 1977; Mengel et al., 2001). Yang and
Janssen (1997) reported that straw and farmyard manure are important organic inputs in northern
China to maintain or even increase the SOM content.
Manure from cattle and other livestock supplies an estimated 30% of the N needs for crop
production in the northeastern United States and is an important source of N in other livestock-
intensive regions (Bandel and Fox, 1984). In Asian countries such as India, Pakistan, Bangladesh,
and Sri Lanka, the Philippines and China farmyard manures are the major source of nutrient supply
on small farm holdings (Fageria and Gheyi, 1999). Proper and efficient management of manure on
cropland is important for improving the economics of crop production and for minimizing adverse
impacts on water quality (Jokela, 1992).
Manure has long been considered a desirable soil amendment and reports of its effects on soil
properties are numerous (Sommerfeldt and Chang, 1985; Campbell et al., 1986; Tester, 1990).
Manure increases the availability, persistence, and movement of phosphorus (Abbott and Tucker,
1973). Abbott and Tucker (1973) found that P concentration was higher under manured cotton than
under either the control or inorganic nitrogen or P treatments. Manure applied in 1965 and 1967
increased by 35% the P uptake of alfalfa over that of control in 1970. Hannapel et al. (1964) found
that OM treatments increased the movement of P in calcareous soils.
Exchangeable K builds up in soil when large amounts of manure are applied (Mathers and
Stewart, 1974). Pratt and Laag (1977) reported that manure containing 1.6-2.2% N appeared to
mineralize at the rate of 40-50% during the first year after application, 10-20% during the second
year, and 5% during the third year in the irrigated soils of southern California. Meek et al. (1982)
reported that the application of manure resulted in an increase of OM, increase of K and P availabil-
ity in a silty clay soil, and an N mineralization rate of about 5% after the first year. The prerequisite
of the use of farmyard manure is that it should be well decomposed to bring beneficial effects for
plant growth. An undecomposed manure may have a high C/N ratio, may liberate some harmful
products during decomposition, and may consequently bring harmful effects for plant growth.
4.8.8 u
se
of
m
unICIpalItY
C
ompost
Municipality compost is a good source of OM, if it is adequately transformed into compost material.
Composting manure produces a stabilized product that can be stored or spread with little odor or
fly-breeding potential (Fageria, 2002). Brady and Weil (2002) defined composting as the practice
of creating humus-like organic materials outside the soil by mixing, piling, or otherwise storing
organic materials under conditions conducive to aerobic decomposition and nutrient conservation.
