Performance evaluation of different soil infiltration models under the long-term conservation agriculture based management practices

Aim: This study aimed to assess the long-term impacts of various conservation agriculture practices on the infiltration characteristics of soil and to evaluate effectiveness of Kostiakov, Green and Ampt, and Philip models in predicting the infiltration rates. Methodology: The treatments examined included the permanent broad bed (PBB), PBB with residue (PBB+R), permanent narrow bed (PNB), PNB with residue (PNB+R), zero tillage (ZT), and ZT with residue (ZT+R) and conventional tillage (CT). Infiltration models were fitted to the experimental data and performance of each model was evaluated using statistical criteria. Results: Initial infiltration rate was maximum in PBB+R, which was 111.5% higher than in conventional tillage CT (lowest). Cumulative infiltration across all the treatments followed in the order of: PBB+R had the highest, followed by PNB+R>ZT+R>PBB>PNB>ZT>CT. The CA– based management practices showed 31.4– 85.2% higher observed steady state infiltration rate than CT. The model derived parameters like “a” value of Kostiakov, “ic” of Green and Ampt and “S” of Philip were higher under PBB+R than CT by 138.6, 154.3 and 112.1%, respectively. Kostiakov model performed the best for predicting infiltration rates with the highest R2≥0.92 and the lowest errors (RMSE≤1.26 cm hr–1, ARE≤0.76 cm hr–1 and MAE≤0.96 cm hr–1). Interpretation: Therefore, it was proventhat the empirical Kostiakov model could effectively represent the infiltration process in soil. Key words: Conventional tillage, Infiltration models, Kostiakov model, Permanent broad bed, Residue