Influence of no-till cover crops on the physical and hydraulic properties of a Paleudult

Abstract

The influence of a single species cover crop on soil hydraulic properties during one growing season are well known. However, the influence of multi-year and multi-species cover crops on soil physical and hydraulic properties are not yet fully understood. The current study was set up using a completely randomized block design during 2021 and 2022, it investigated the effects of a multi-species cover crop (winter wheat (Triticum aestivum L.), crimson clover (Trifolium incarnatum L.), triticale (Triticale hexaploide Lart), hairy vetch (Vicia villosa), oats (Avena sativa), and cereal rye (Secale cereale L.)) on bulk density, soil organic carbon, saturated hydraulic conductivity, pore-size distribution, and volumetric water content at 0, -0.4, -1, -2.5, -5, -10, -20, -33, -100, and -1 500 kPa soil water pressures. The soil samples were collected in 10 cm increments from the soil surface down to 30 cm. After 2 years, the results showed that cover crop reduced bulk density by 17% as compared with no cover crop management. Further, the cover crop-induced increases in soil organic carbon as well as in macro- and mesoporosity led to 23, 25, and 28% increases in volumetric water content at 0, -33, and -100 kPa soil water pressures respectively, relative to no cover crop management. When comparing the two years of the study, under cover crop management alone, saturated hydraulic conductivity was higher in 2021 as compared to 2022, which suggests that cover crop-induced improvements in some hydraulic properties may not be proportional over time. In general, cover crops improved the measured soil hydraulic properties after 2 years and this has the potential to be beneficial for improving soil water storage.