Infiltration Characteristics under No‐Till and Clean‐Till Furrow Irrigation

Abstract

AbstractTillage or the lack of tillage affects infiltration and its variability across the field. To quantify infiltration characteristics of soil under no‐till and clean‐till furrow irrigated systems, a 3‐yr rotation of wheat (Tritium aestivum L.)‐sorghum [Sorghum bicolor (L.) Moench]‐fallow on a Pullman sandy clay loam soil (fine, mixed, thermic Torrentic Paleustoll) was initiated. Treatments were no‐till and clean‐till with or without wheel traffic. Soil water contents, water advance times down the furrow, wetted cross‐sectional area of flow, and cumulative furrow infiltration during three irrigations for each cropping event were determined. No‐till treatments conserved significantly more soil water (3.0 cm) during the fallow periods than clean‐till. Average water advance times to the end of the field were 301 and 175 min for no‐till and clean‐till, respectively. Wheel traffic significantly decreased advance times, by a factor of 1.98, during the initial irrigations at planting with no effect on subsequent irrigations. Wetted cross‐sectional area in no‐till furrows was significantly greater than in clean‐till during sorghum irrigations, averaging 0.0206 and 0.0093 m2, respectively. However, these factors did not contribute to a consistent increase in infiltration in the no‐till treatments. Grain yields for sorghum were significantly greater in no‐till than clean‐till: 4147 and 3584 kg ha−1, respectively, but clean‐till wheat yields (5414 kg ha−1) were significantly greater than no‐till yields (4657 kg ha−1). No‐till conserved more water during the fallow periods, but surface characteristics of planting wheat no‐till in sorghum residue may decrease uniformity over long furrows.