FIELD EVALUATION OF A DUAL BENTLEG PLOW

The objective of the present study was to test a dual bentleg (DBL) plow for deep tilling purposes. The experiments were conducted on a moderately compacted clay-loam soil. The performance of the plow was compared with a three bottom general purpose moldboard plow (MB) common in local farms. The tractor forward speed was maintained at 2.8 km h^-1. The power requirement of the DBL plow was 6.7-19 kW for the plowing depths of 250-450 mm compared to 13.4 kW for the MB plow at 250 mm depth. The draft per unit width of the DBL plow was less than 0.5, 1.0 and 1.3 times that of MB plow at working depths of 250, 350 and 450 mm, respectively. The cross-sectional area of the disturbed soil was almost doubled as the plowing depth was increased from 250 to 450 mm. The DBL plow disrupted the soil as wide as 1.8 to 2.5 times of its nominal width, but the tilled depth was not uniform. The soil underneath the plow shank was disturbed to a depth rarely exceeding one-half of the target depth. Specific resistance of the DBL plow was lower than the MB. A decrease in soil bulk density, an increase in cumulative water infiltration and undisturbed residue cover were among desirable characteristics. The optimum shank spacings between two subsequent rows were found to be 1400 and 2100 mm for the nominal plowing depths of 350 and 450 mm, respectively.