Temporal Dynamics and Kostiakov Modelling of Soil Infiltration under a Rice–Mustard Cropping System

Abstract

Soil infiltration is an important soil physical property controlling water entry into the soil profile and influencing irrigation efficiency, runoff, and soil-water availability. This study characterised field infiltration under a rice–mustard cropping system at the research farm of Sardar Vallabhbhai Patel University of Agriculture and Technology (SVPUAT), Meerut, Uttar Pradesh, India, during the transition from mustard harvest to rice establishment. Infiltration was measured at three randomly selected locations using a double-ring infiltrometer following ASTM D3385-18. Cumulative infiltration and the mean infiltration rate were recorded over 350 min, and cumulative infiltration was fitted with the Kostiakov equation using nonlinear least-squares estimation. The soil had a bulk density of 1.33 Mg m⁻³, particle density of 2.40 Mg m⁻³, total porosity of 44.06%, soil organic carbon of 0.69%, pH of 7.08, electrical conductivity of 0.18 dS m⁻¹, and 64.59% sand, 22.92% silt, and 12.49% clay. Cumulative infiltration increased from 8.00 mm at 5 min to 17.00 mm at 230 min and remained unchanged through 350 min, whereas the mean infiltration rate declined from 1.60 to 0.049 mm min⁻¹. The fitted Kostiakov equation was I = 5.874t⁰·¹⁹¹ (R² = 0.979; RMSE = 0.487 mm; MAE = 0.443 mm). The results provide site-specific baseline information on soil water-entry behaviour during the post-mustard/pre-rice transition. The relatively high sand content may have contributed to the rapid initial infiltration, but this interpretation should be considered cautiously because infiltration is also affected by bulk density, pore continuity, antecedent soil-water status, and measurement conditions. The Kostiakov relationship adequately described the observed cumulative infiltration and may be useful for preliminary interpretation of infiltration behaviour and soil-water management under similar field conditions.