impact of farmers' organic farming practices on soil properties in ...

Under sugarcane based cropping system, the nitrogen content added to soil through
<strong>organic</strong>s varied from 111.00 (S1) to 152.20 (S2) kg per ha per year and phosphorus content
from 48.35 (S1) to 88.80 (S3) kg per ha per year and potassium content from 87.30 to 159.60
(S3) kg per ha per year.
In case <strong>of</strong> vine yard system, addition <strong>of</strong> nitrogen through <strong>organic</strong>s ranged from 89.00
(V2) to 150.80 (V3) kg per ha per year, phosphorus content varied from 49.30 (V2) to 74.20
(V3) kg per ha per year and potassium content ranged from 70.60 (V2) to 112.80 (V1) kg per
ha per year.
4.2 EFFECT OF ORGANIC FARMING ON SOIL PHYSICAL
PROPERTIES
4.2.1 Soil texture (Table 4)
Particle size distribution <strong>of</strong> cotton based cropping system <strong>of</strong> four <strong>organic</strong> <strong>farming</strong> soil
samples revealed that the average sand, silt and clay content were 12.14, 22.50 and 63.33
per cent, respectively. While in the conventional <strong>farming</strong>, they were 12.32, 23.78 and 62.35
per cent, respectively.
In kharif jowar cropping system, soils <strong>of</strong> two <strong>organic</strong> farms on an average, recorded
sand, silt and clay content <strong>of</strong> 12.61, 23.16 and 63.67 per cent, respectively, while in the
conventional <strong>farming</strong>, they were 13.17, 24.45 and 62.39 per cent, respectively.
An average <strong>of</strong> 13.29, 22.76 and 61.60 per cent <strong>of</strong> sand, silt clay contents were
observed in soils <strong>of</strong> rabi jowar cropping system under <strong>organic</strong> <strong>farming</strong>. Soils <strong>of</strong> conventional
<strong>farming</strong> under same cropping system contained 12.70, 24.20 and 60.37 per cent <strong>of</strong> sand, silt
clay, respectively.
In sugarcane based cropping system, the average <strong>of</strong> four <strong>organic</strong> farm soils
accounted for sand, silt and clay content <strong>of</strong> 11.57, 23.51 and 63.66 per cent, respectively as
compared to 11.60, 24.79 and 61.84 per cent, respectively in soils <strong>of</strong> conventional farms.
In vineyard system, the average <strong>of</strong> sand, silt and clay content <strong>of</strong> soils <strong>of</strong> <strong>organic</strong> farms
was 10.15, 20.23 and 68.70 per cent, respectively. While in the conventional <strong>farming</strong>, they
were 11.96, 20.63 and 66.72 per cent, respectively.
All the soils under both <strong>organic</strong> and conventional <strong>farming</strong> were clay in texture,
irrespective <strong>of</strong> cropping system followed.
4.2.2 Bulk density
The data on the effect <strong>of</strong> <strong>organic</strong> <strong>farming</strong> on bulk density <strong>of</strong> soils under different
cropping systems is given in Table 5, 6, 7 and 8.
Under cotton based cropping system (Table 5), on an average, the soils <strong>of</strong> four farms
showed a reduction in bulk density <strong>of</strong> surface soil from 1.42 Mg m -3 in conventional farms to
1.31 Mg m -3 in <strong>organic</strong> farms and from 1.44 to 1.35 Mg m -3 in subsurface soil. The average
decrease in bulk density was to the extent <strong>of</strong> 7.75 per cent and 6.25 per cent in surface and
subsurface soil, respectively. Among the soils <strong>of</strong> four <strong>organic</strong> farms, the highest decrease in
bulk density was observed in soils <strong>of</strong> C4 farmer (9.40%) followed by C2 farmer (7.30%) and
lowest reduction was observed in soils <strong>of</strong> C 1 farmer (3.60%).
In kharif jowar based cropping system (Table 6), the average <strong>of</strong> two soils indicated a
reduction in bulk density from 1.40 to 1.25 Mg m -3 and 1.44 to 1.30 Mg m -3 in surface and
subsurface soils, respectively. The overall reduction in bulk density <strong>of</strong> soil due to <strong>organic</strong>
<strong>farming</strong> worked to 10.7 per cent in surface soil and 9.72 per cent in subsurface soil. The
highest decrease in bulk density <strong>of</strong> soil was observed in soils <strong>of</strong> K1 farmer (10.65%).
In rabi jowar based cropping system (Table 6), the average <strong>of</strong> three soils indicated a
decrease in bulk density in both surface and subsurface soils (1.44 to 1.32 Mg m -3 and 1.48 to
1.34 Mg m -3 , respectively). Among three <strong>organic</strong> farms, soils <strong>of</strong> R1 farm showed a highest
reduction in bulk density (12.00%).