Information on the effect of soil compaction on soil mechanical properties such as degree of compaction,compression and shear strength of tropical soils of Nigeria under different machinery traffic passes is very scar...Information on the effect of soil compaction on soil mechanical properties such as degree of compaction,compression and shear strength of tropical soils of Nigeria under different machinery traffic passes is very scarce.Field experiment was conducted in a tilled and compacted sandy clay loam(Alfisol)in Akure,Nigeria,under different machinery traffic passes to determine compaction effects on bulk density,compression strength,degree of compaction and the shear strength of soil.Four plots,A,B,C and D of area 20 m×50 m each were used for the field experiment.Treatment plot A was tilled with a tractor-mounted disc plough,and the remaining three plots:B,C and D were subjected to 5,10 and 15 to and fro passes,respectively,using heavy duty Mercy Fergusson tractor model 4355(3.82 Mg).The treatments were replicated three times in a randomized complete block design.Compacted plots progressively increased the bulk density from 1.63 g/cm^(3) to 1.90 g/cm^(3),but the highest bulk density was observed in plots under 15 traffic passes with the value of(1.90±0.23)g/cm3.The percentage of soil compaction varies from 90.5%to 97%at the 0-10 cm soil layer.The compression strength of soil increased from 31.00 kPa to 42.05 kPa and from 29.68 to 65.44 kPa at the 0-10 cm and 10-20 cm soil layers,respectively,which resulted in the increased shear strength from 15.79 kPa to 21.03 kPa and 14.8 kPa to 32.72 kPa at the 0-10 cm and 10-20 cm in plots under 5 and 15 traffic passes,respectively.Plot A(tilled soil)had the lowest bulk density,degree of compaction and compression strength with values(1.51±0.19)g/cm^(3),88.2%,and(12.15±0.37)kPa,respectively,and consequently the lowest shear strength of(6.02±1.23)kPa,which enhanced air movement and microbial activities in the soil.Soil under 15 traffic passes,especially at the 10-20 cm soil layer,may result in poor root penetration when cropped but can be very reliable and consistent when used for structural purposes.展开更多
文摘Information on the effect of soil compaction on soil mechanical properties such as degree of compaction,compression and shear strength of tropical soils of Nigeria under different machinery traffic passes is very scarce.Field experiment was conducted in a tilled and compacted sandy clay loam(Alfisol)in Akure,Nigeria,under different machinery traffic passes to determine compaction effects on bulk density,compression strength,degree of compaction and the shear strength of soil.Four plots,A,B,C and D of area 20 m×50 m each were used for the field experiment.Treatment plot A was tilled with a tractor-mounted disc plough,and the remaining three plots:B,C and D were subjected to 5,10 and 15 to and fro passes,respectively,using heavy duty Mercy Fergusson tractor model 4355(3.82 Mg).The treatments were replicated three times in a randomized complete block design.Compacted plots progressively increased the bulk density from 1.63 g/cm^(3) to 1.90 g/cm^(3),but the highest bulk density was observed in plots under 15 traffic passes with the value of(1.90±0.23)g/cm3.The percentage of soil compaction varies from 90.5%to 97%at the 0-10 cm soil layer.The compression strength of soil increased from 31.00 kPa to 42.05 kPa and from 29.68 to 65.44 kPa at the 0-10 cm and 10-20 cm soil layers,respectively,which resulted in the increased shear strength from 15.79 kPa to 21.03 kPa and 14.8 kPa to 32.72 kPa at the 0-10 cm and 10-20 cm in plots under 5 and 15 traffic passes,respectively.Plot A(tilled soil)had the lowest bulk density,degree of compaction and compression strength with values(1.51±0.19)g/cm^(3),88.2%,and(12.15±0.37)kPa,respectively,and consequently the lowest shear strength of(6.02±1.23)kPa,which enhanced air movement and microbial activities in the soil.Soil under 15 traffic passes,especially at the 10-20 cm soil layer,may result in poor root penetration when cropped but can be very reliable and consistent when used for structural purposes.
