Impact of organic and conventional farming practices on soil quality
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Date
2018
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Publisher
CCSHAU
Abstract
Organic agricultural systems aim at reducing the use of synthetic fertilizers and pesticides in order to
improve soil quality and food safety. Despite the integral role of the management practices in
agricultural production, there is a limited understanding of the effects of organic farming system on soil
properties for seeking as an alternative to the conventional practices. The impact of organic farming on
soil quality in terms of changes in various soil properties as compared to conventional farming was
evaluated. Surface soil samples were collected from organic farm under different cropping systems visa-
vis agricultural and horticultural cropping systems and their adjoining conventional farms from 25
different locations in 11 districts of Haryana. The texture of soils at different locations varied between
sand to clay loam, representing almost all the soil types of the state. The soil samples were analyzed for
various soil physical, chemical and biological properties. Organic farming system decreased the bulk
density of soils at majority of the locations. The average bulk density values of all the locations reduced
significantly from 1.47 to 1.45 Mg m-3 under organic as compared to conventional farming system. The
water stable aggregates (>0.25 mm), moisture content at field capacity and plant available water were
found to increase. Shifting from conventional to organic farming had no effect on pH and EC but
reduced the CaCO3 significantly.Organic farming significantly increased the SOC from 51% to 62% as
a result of which the SCS increased from 11.17 to 13.29 Mg ha-1 over conventional farming. The
magnitude of increase in LOC, POC and MOC was 48.9, 23.6 and 14.7 %, respectively. Different
organic carbon pools in various fractions followed the order MOC > POC > LOC. In addition, an
increase in macro and micro nutrients was also observed. The total bacterial, fungal and actinomycetes
counts were increased by 56.9, 55.2 and 49.5%, respectively, than those in the conventionally managed
soils. Overall, population of rhizobium, azotobacter, azospirillum and PSB increased significantly by
44.1, 39.0, 47.1 and 43.5%. Under organic farming, dehydrogenase activity, alkaline phosphatase
activity and MBC increased by 57.5, 22.8 and 69.1 %, respectively, as compared to conventional
farming system. It is concluded that the conversion of land from conventional to organic farming is
good for maintaining soil quality and could be adopted or promoted as an alternative to the
conventional farming practices for sustainable use of natural resources, and food safety coupled with
climate change.