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

In kharif jowar based cropping system, the average <strong>of</strong> two soils indicated increase <strong>of</strong>
available potassium content from 579 to 606 kg per ha and 560 to 580 kg per ha in surface
and subsurface soils, respectively. The average increase in potassium due to <strong>organic</strong> <strong>farming</strong>
worked to 4.70 per cent in surface soil and 3.60 per cent in subsurface soil. The highest
increase in potassium content was observed in K 1 farmer (4.33%).
The average <strong>of</strong> three soils under rabi jowar based cropping system indicated an
increase <strong>of</strong> potassium in both surface and subsurface soils (542 to 560 kg/ha and 529 to 544
kg/ha, respectively). The average increase in potassium in surface and subsurface soil was
3.32 per cent and 2.83 per cent, respectively. Among three soils, soils <strong>of</strong> R 1 farmer showed a
highest increase in potassium (3.83%) due to <strong>organic</strong> <strong>farming</strong>.
In sugarcane based cropping system, available K2O content in soils under <strong>organic</strong>
farms ranged from 584 (S2) to 608 (S3) kg per ha, while it ranged from 561 (S2) to 581 (S1) kg
per ha in conventional farms. On an average, the available potassium content in soils due to
<strong>organic</strong> <strong>farming</strong> increased from 590 to 613 kg per ha in surface and 557 to 581 kg per ha in
subsurface soils. The highest increase in potassium content was in soils <strong>of</strong> S3 farmer (5.92%),
followed by S2 farmer (4.10%) and lowest increase was noticed in soils <strong>of</strong> S1 farmer (2.70%).
All the soils contained more available K in surface than in subsurface soil.
In vineyards, the average <strong>of</strong> three <strong>organic</strong> farms indicated an increase <strong>of</strong> available
potassium content from 598 to 615 kg per ha and 575 to 589 kg per ha in surface and
subsurface soils, respectively. The highest and lowest increase in potassium was recorded in
soils <strong>of</strong> V 3 (3.70%) and V 2 farmer (1.44%), respectively.
4.4.4 Available sulphur in soil
The results on available sulphur content <strong>of</strong> soils as influenced by <strong>organic</strong> <strong>farming</strong> are
presented in Table 17. The available S content in all the soils was above critical limit
irrespective <strong>of</strong> type <strong>of</strong> <strong>farming</strong> and cropping system followed.
The results from cotton based cropping system showed that there was increase in
available sulphur content due to <strong>organic</strong> <strong>farming</strong>. In <strong>organic</strong> farms, mean available sulphur
ranged from 27.75 kg per ha (C1) to 31.87 kg per ha (C4). The soils <strong>of</strong> C4 farmer showed
greater increase in sulphur (14.30%), followed by C 1 farmer (11.60%) and lowest increase
was observed in soils <strong>of</strong> C2 farmer (9.52%). On an average, sulphur content in surface soil
increased from 27.68 kg per ha in conventional farms to 30.50 kg per ha in <strong>organic</strong> farms,
accounting for an increase <strong>of</strong> 10.20 per cent. Whereas, in subsurface soil, available S
increased from 25.26 kg per ha under conventional <strong>farming</strong> to 27.94 kg per ha under <strong>organic</strong>
<strong>farming</strong>, accounting for an increase <strong>of</strong> 10.60 per cent.
In kharif jowar based cropping system, the average <strong>of</strong> two soils indicated an increase
in sulphur content from 34.12 to 35.62 kg per ha and 31.87 to 32.75 kg per ha in surface and
subsurface soils, respectively. The average increase in sulphur content due to <strong>organic</strong>
<strong>farming</strong> worked to 4.40 per cent in surface soil and 2.80 per cent in subsurface soil. The
highest increase in sulphur content was observed in soils <strong>of</strong> K2 farmer (3.90%).
In rabi jowar based cropping system, the average <strong>of</strong> three soils showed an increase
in available sulphur content <strong>of</strong> surface soil from 25.11 kg per ha in conventional farm to 26.51
kg per ha in <strong>organic</strong> farm and in the subsurface it increased from 23.21 to 24.58 kg per ha.
Among the three <strong>organic</strong> farms, the highest increase in available sulphur content over
conventional <strong>farming</strong> was observed in soils R1 farmer (6.50%) and lowest increase was in
soils <strong>of</strong> R 3 farmer (4.70%).
The soils <strong>of</strong> sugarcane based cropping system showed an increase in available
sulphur due to <strong>organic</strong> <strong>farming</strong> practice. The average increase in available sulphur over
conventional <strong>farming</strong> was 8.41 per cent and 8.60 per cent in surface and subsurface soils,
respectively. The mean available sulphur in soils <strong>of</strong> <strong>organic</strong> farms ranged from 23.25 kg per
ha (S4) to 31.47 kg per ha (S1). While, in conventional farms it ranged from 21.75 kg per ha
(S4) to 28.87 kg per ha (S1). The highest increase in available sulphur content due to <strong>organic</strong>
<strong>farming</strong> was noticed in soils <strong>of</strong> S1 farmer (10.00%) and lowest increase was in soils <strong>of</strong> S4
(6.90%).
The available sulphur content <strong>of</strong> three soils under vineyards recorded an average <strong>of</strong>
36.41 and 33.68 kg per ha in surface and subsurface soils, respectively under <strong>organic</strong> <strong>farming</strong>