Assessment of soil compaction due to the motion of Prime mover and tillage machinery in temperature region of Kashmir Valley
The study was undertaken to assess the impact of prime movers (40 hp and 50 hp) and agricultural machinery (cultivator, disc harrow and rotavator) on soil compaction. Initially, the prime movers were operated at three speeds (2 kmph, 3 kmph and 5 kmph) for 1, 2 and 3 passes and responses were measured in terms of bulk density (gcm-3), particle density (gcm-3), porosity (%), cone index (kPa), infiltration rate (cmh-1), hydraulic conductivity (cmh-1) and particle size distribution (mm). The experiments were planned as per Randomized Block Design (RBD). It was observed that bulk density, particle density and cone index increased with an increase in the number of passes from 1 to 3. Maximum percentage increase of 5.82 % bulk density, 2.78 % particle density and 26.96 % cone index from the initial values were observed in the operation of 50 hp tractor without implement. The infiltration rate showed a decrease of 1.08% and 1.5% after 1 pass for 40 and 50 hp tractor, respectively. Mass mean diameter (MMD) of soil decreased with the increase in the number of passes from 1 to 3 and the maximum decrease of 11.24% was recorded during operation of 50 hp tractor. In the next phase, three secondary tillage implements viz. cultivator, disc harrow and rotavator were attached with the 50 hp prime mover at three different inflation pressure (0.8 kg cm-2, 1.2 kg cm-2, 1.5 kg cm-2) for 1, 2 and 3 passes, respectively. It was observed that the bulk density decreased by 27.57% for cultivator, 29.87% disc harrow and 30.20% rotavator. The cone index decreased with number of passes for all the implements and the maximum value of 36% was associated with rotavator. About 45% increase in infiltration rate, 25 % hydraulic conductivity and 37.70 % decrease in mean mass diameter (MMD) was recorded with the operation of rotavator after three passes.