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market-farming - [Market-farming] ENVIRONMENTAL Benefits of organic and IRV over "conventional" farming

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  • From: "Jill Taylor Bussiere" <jdt AT itol.com>
  • To: <market-farming AT lists.ibiblio.org>
  • Subject: [Market-farming] ENVIRONMENTAL Benefits of organic and IRV over "conventional" farming
  • Date: Tue, 4 Feb 2003 07:41:56 -0600

Other Benefits

Environmental benefits
In addition to those mentioned above, there are other benefits resulting
from organic farming and intensive rotational grazing. According to an
article entitled "Environmental Benefits of Improved Grazing Management" by
Robert Hendershot, Resource Conservationist for the Natural Resources
Conservation Service, "the environmental benefits of well managed pasture
include reduced soil erosion; improved air and water quality; better plant
diversity, vigor and production, and an improved fish and wildlife habitat."
He cites two studies, one by the University of Wisconsin, and the other by
USDA-Agricultural Research Service, North Appalachian Experimental
Watershed, Coshocton, Ohio, that demonstrate that "pastures are the best
'crop' for reducing runoff, erosion, and phosphorus pollution over any other
land use, and that both surface and ground water in pastured watersheds are
"just as good or better than water leaving the adjacent pristine wooded
watershed. Pasture soils are a terrific biological filter to recover
nutrients passing through the soil. Grass roots are active nearly
year-round and thus can recover nutrients efficiently from pasture soils
that can leach from other land uses."

According to the US EPA Index of Watershed indicators
(http://www.epa.gov/iwi/1997/a/dback12b.html) Wisconsin is in the moderate
to high area of potential nitrogen runoff, attributed to commercial
fertilizer applications, uptake of nitrogen by crops, and potential nitrogen
loadings from confined animal waste disposal.

"The deteriorating quality of Wisconsin's ground and surface waters is of
growing public concern. Inadequate management of livestock manures and
over-application of commercial fertilizers are now considered major sources
of nitrate leaching and phosphorus runoff in the state. In Wisconsin, an
estimated 40 percent of rivers and streams and over 90 percent of lakes are
degraded by non-point source pollution , the primary source of which is
considered to be agriculture. (E. Odgers, "Regulations bolster voluntary
programs for clean up of agricultural nonpoint "bad actors" in Wisconsin see
Manure Management in Wisconsin: Results of the 1995 Wisconsin Farmer Poll By
Douglas Jackson-Smith, Monica Nevius, Bradford Barham
http://www.wisc.edu/pats/absmanure.htm)

Organic farming eliminates commercial fertilizer applications, and IRG
eliminates confined animal waste disposal.

Global Warming

There are several emissions related to global warming. CH4 is produced by
the decomposition of manure. Manure that is stored or treated in systems
promoting anaerobic conditions, such as liquid lagoons, ponds, tanks, or
pits, tends to promote more CH4 than that on pasture or range, which
decomposes aerobically, producing very little or no CH4. Feedlot cattle
which are fed a high energy grain diet generate manure with high
CH4-producing capacity. Range or grazed cattle fed a low energy diet of
forage material produce manure with about 50 percent of the CH4-producing
potential of feedlot cattle manure. (Inventory of US Greenhouse Gas
Emissions and Sinks: 1990-2000 April 2002 EPA 430-R-02-003)

N2O emissions are also of concern. "Agricultural soil management is the
largest source of N2O in the United States. "The population of beef cattle
in feedlots, which tend to store and manage manure on site, also increased,
resulting in increased N2O emissions from this animal category. Although
dairy cow populations decreased overall, the population of dairies managing
and storing manure on site - as opposed to using pasture, range, or paddock
or daily spread systems - increased. Therefore, the increase in dairies
using on-site storage to manage their manure results in increased N2O
emissions." (same as above)

"We found that converting cropland to grassland, such as in the Conservation
Reserve Program (CRP) significantly reduces N2O emissions from agriculture.
This mitigation could account for 4 to 13% of the total emissions due to
fertilization. Our study shows that reducing the cropland area and reducing
fertilizer use on soybeans, corn and wheat can significantly reduce GHG
emissions from US agriculture." (MUMMEY DANIEL L ,SMITH JEFFREY L ,BLUHM
GEORGE , Model Assessment of Alternative Soil Management Practices on N2O
Emissions from US Agriculture United States Department of Agriculture
Agricultural Research Service, 1997)
"Commercial fertilizers do not add organic matter to the soil. Unless
organic matter is added, the porosity and the ability of holding water in
the soil will decrease. Under those conditions, added fertilizers can not be
taken up efficiently." This leads to N2O emissions.
(http://www1.ldc.lu.se/iiiee/SOURCES/FARMING/FARMING_HOME.HTML#Fertilisers)

Cultivation of histosols (soils rich in organic matter) also results in N2O
emissions, therefore, raising pasture-fed dairy animals, because they obtain
more of their food from pasture and eat less grain than feedlot dairy cows,
results in fewer acres tilled. (reference - logic)

"Agriculture is the main source of methane (CH4) and nitrous oxide (N2O)
emissions. CH4 emissions from domestic ruminants, animal waste and rice
fields were estimated to be 65-100 (IPCC, 1992; Hogan, 1993), 20-30 (Safley
et al., 1992) and 25.4-54 (IPCC, 1996) Tg/yr. N2O is produced primarily by
microbial processes in the soil (Bouwman, 1990; Duxbury and Mosier, 1993).
It was estimated that more than 75% of the anthropogenic N2O sources are
derived from agriculture, the total amount was 4.2Tg N2O-N/yr (Mosier et
al., 1998b)." (Methodological and Technological issues in Technology
Transfer Chapter 11.2.2, United Nations








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