Abstract
To evaluate soil erodibility under different land uses and to study the applicability of nomograph for estimation of soil erodibility a field experiment was conducted under both natural and simulated rainfall conditions under four land uses viz. barren, cultivated, grassland, and forest in the subβmountainous tract of Punjab (India). Measured soil erodibility (K) values varied from 0Β·33 to 0Β·67 under natural rainfall conditions and from 0Β·23 to 0Β·40 under simulated rainfall conditions. Among different land uses, measured K was in the order of barren > cultivated > grassland > forest soils. The values of the K estimated by nomograph were very low as compared to the observed values. The trends were also in contrast to these observed values of K under simulated and natural rainfall conditions. To modify nomograph equation, different ranges of aggregate sizes were correlated with soil loss. It was observed that water stable aggregates (WSA) <2βmm size had a significant correlation with soil loss under both natural (rβ=β0Β·88) and simulated (rβ=β0Β·76) rainfall conditions. So the nomograph equation was modified to include the M parameter based on WSA <2βmm size. The value of K estimated from the modified nomograph had a significant correlation with measured values of K under both the natural and simulated rainfall conditions. Copyright Β© 2009 John Wiley & Sons, Ltd.