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

In cotton based cropping system (Table 10), on an average, the <strong>organic</strong> carbon
content increased from 0.59 per cent in conventional farm to 0.73 per cent in <strong>organic</strong> farm in
surface soil and from 0.52 to 0.67 per cent in subsurface soil accounting for an increase <strong>of</strong>
23.72 per cent in surface soil and 28.84 per cent in subsurface soil. Among the soils <strong>of</strong> four
<strong>organic</strong> farms, the highest increase in <strong>organic</strong> carbon content was observed in soils <strong>of</strong> C 4
farmer (47.30%), followed by C3 farmer (27.10%) and lowest increase was observed in soils
<strong>of</strong> C2 farmer (14.10%).
In kharif jowar based cropping system (Table 11), the average <strong>of</strong> two farms indicated
an increase <strong>of</strong> <strong>organic</strong> carbon <strong>of</strong> soil due to <strong>organic</strong> <strong>farming</strong> from 0.49 to 0.76 per cent and
0.40 to 0.64 per cent in surface and subsurface soils, respectively. The average increase in
surface soil was 55.10 per cent and subsurface was 60.00 per cent. The soils <strong>of</strong> K1 recorded
higher increase in <strong>organic</strong> carbon (70.45%) than K2 farmer (40. 42%).
In rabi jowar based cropping system (Table 11), the average <strong>of</strong> three soils showed an
increase in <strong>organic</strong> carbon content in both surface and subsurface soils (0.40 to 0.72% and
0.36 to 0.67%, respectively). The surface soils contained higher amount <strong>of</strong> <strong>organic</strong> carbon
than subsurface soil. But, however, the average increase in <strong>organic</strong> carbon content due to
<strong>organic</strong> <strong>farming</strong> was more in subsurface soil (86.10%) than in surface soil (80.0%). Among
the three <strong>organic</strong> farms the highest mean <strong>organic</strong> carbon content was observed in soils <strong>of</strong> R1
farmer (0.72) and lowest was in soils <strong>of</strong> R3 farmer (0.68%).
In sugarcane based cropping system (Table 12), the highest increase in <strong>organic</strong>
carbon due to <strong>organic</strong> <strong>farming</strong> practice was recorded in S 3 farmer (45.76%), followed by S 2
(37.71%) and lowest increase was in S4 (24.04%). The mean <strong>organic</strong> carbon content <strong>of</strong> soils
<strong>of</strong> <strong>organic</strong> farms ranged from 0.67 per cent (S4) to 0.81 per cent (S1). The average <strong>of</strong> four
soils showed an increase <strong>of</strong> <strong>organic</strong> carbon from 0.58 to 0.77 per cent and 0.54 to 0.72 per
cent in surface and subsurface soils, respectively due to <strong>organic</strong> <strong>farming</strong> practice. The overall
increase in <strong>organic</strong> carbon content was 33.00 per cent.
In vine yard system (Table 13), the average <strong>of</strong> three soils indicated an increase in
<strong>organic</strong> carbon due to <strong>organic</strong> <strong>farming</strong> from 0.79 to 1.02 per cent and 0.75 to 0.91 per cent in
surface and subsurface soils, respectively. The average increase in <strong>organic</strong> carbon in surface
soil was 29.10 per cent and subsurface was 21.3 per cent. The highest and lowest increase in
<strong>organic</strong> carbon was recorded in soils <strong>of</strong> V3 farmer (33.80%) and V1 farmer (19.42%),
respectively.
4.3.3 Cation exchange capacity
The data on cation exchange capacity (CEC) <strong>of</strong> soils under different cropping
systems is given in Table 10, 11, 12 and 13.
Under cotton based cropping system (Table 10), the average CEC <strong>of</strong> four soils
showed an increase in surface soil from 57.88 cmol (p+) per kg in conventional farms to 62.38
cmol (p+) per kg in <strong>organic</strong> farms. It increased from 56.33 to 60.53 cmol (p+) per kg in
subsurface soil. The average increase in CEC was to the extent <strong>of</strong> 7.80 per cent and 7.45 per
cent in surface and subsurface soils, respectively. Among the soils <strong>of</strong> four <strong>organic</strong> farms, the
highest increase in CEC was observed in soil C 4 farmer (10.20%), followed by C 3 farmer
(7.80%) and lowest was noticed in soils <strong>of</strong> C1 farmer (5.40%).
In kharif jowar based cropping system (Table 11), the average <strong>of</strong> two soils indicated
an increase <strong>of</strong> CEC due to <strong>organic</strong> <strong>farming</strong> from 59.25 to 65.51 cmol (p+) per kg and 58.08 to
63.90 cmol (p+) per kg in surface and subsurface soils, respectively accounting for an
increase <strong>of</strong> 10.60 per cent in surface soil and 10.00 per cent in subsurface soil.
The average <strong>of</strong> three soils showed under rabi jowar cropping system (Table 11)
indicated an increase <strong>of</strong> CEC in both surface and subsurface soils (58.45 to 62.94 cmol
(p+)/kg and 56.89 to 61.38 cmol (p+)/kg, respectively). The average increase in CEC due to
<strong>organic</strong> <strong>farming</strong> worked to 7.7 per cent in surface and 7.9 per cent in subsurface soil. Among
the three <strong>organic</strong> farms, soils <strong>of</strong> R2 farm recorded a highest CEC (62.64 cmol (p+)/kg).
In sugarcane based cropping system (Table 12), all the four <strong>organic</strong> farms showed an
increase in CEC due to <strong>organic</strong> <strong>farming</strong> practice. The average increase in CEC <strong>of</strong> soils <strong>of</strong>
<strong>organic</strong> farms over conventional farms was 9.50 and 9.40 per cent in surface and subsurface