Agriculture Reference
In-Depth Information
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ations. In either case, organic olive farms had a higher degree of technical
efficiency in relation to their production level. The efficiency and energy
models indicate that organic farms have the potential to endure well into
the future.
Co
mparing Soils
Soils are of higher quality on organic farms than on conventional farms,
exemplifying the major difference between these two farming methods. Or-
ganic farmers work to build their soil through crop rotations, improving it
for the next generation. Conventional farms tend to use the soil as amedium
to hold the seed, applying the necessary chemicals for the plant to grow. For
example, a Dutch study found substantial differences between the soils from
farms that produced similar crops under organic and conventional man-
agement for seventy years (Pulleman et al. 2003). On these farms, the soil
organic matter content, the earthworm activity, and mineralization were all
greater on organically farmed soils. Further, the organic soils had higher
water-stable aggregation, which indicates that they hold together when wet
and would be less susceptible to erosion. So there are “beneficial effects of
organic farming” related to both the soil biochemical properties and “soil
physical aspects” (157).
In a U.S. study, the soil structure was distinctly different on two adjacent
farms in eastern Iowa: a 35.6 acre (14.4 ha) conventional grain farm and
a 4-acre (1.6 ha) organic vegetable and grain farm (Gerhardt 1997). Both
farms had been in operation since the 1950s, so results indicated the long-
term variations in field methods on silt loam soils. Soil samples gathered
from five sites on each farm underwent multiple tests. Results showed that
the organic farm had significantly deeper topsoil with coarser texture and
higher organic matter, porosity, and earthworm abundance. It did not show
signs of compaction and erosion, which were obvious on the conventional
farm. Crop types varied considerably between the two, and variations in
cropping and tillage affect soil structure. We can conclude that the manage-
ment methods associated with organic farming (e.g., crop rotations, organic
inputs) help maintain and improve soil structure, which will provide better
crop growth.
Variations between how organic matter breaks down in soils on conven-
tional and organic farms was studied in Ohio (Vazquez et al. 2003). Overall,
earthworm population density was much higher in organic soils. Decom-
position was higher on the organic farm, where more soil decomposers are
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