Soil β-glucosidase activity, organic carbon and nutrients in plant tissue in response to cover crop species and management practices

Abstract

Cover crop (CC) management can be improved to enhance carbon storage, microbial activity and fertility in agricultural soils. This study assessed the immediate effect of living CCs and residues, two termination stages (vegetative and flowering) and two termination methods (slash and spray) on soil β-glucosidase activity and soil organic carbon (SOC) levels in a pot experiment. Species tested as CCs were, vetch (Vicia dasycarpa Ten.), pea (Pisum sativum L.), oats (Avena sativa L.), rye (Seale cereal L.) and control (no CC). Delay in termination until flowering stage significantly increased C and C:N ratio content of all the CCs. Living CCs did not influence SOC but stimulated β-glucosidase compared to the control. At one year, rye and oats residues increased SOC compared to other CC residues, while β-glucosidase activity was greater under rye, oats and pea residues than vetch and control. Termination of CCs at flowering stage resulted in greater β-glucosidase activity and SOC levels than the vegetative stage at one year. Termination by slashing had a positive impact on SOC and β-glucosidase activity compared to spraying. The results of this study indicate significant (p < 0.05) sampling time, CC and termination stage interaction effects on SOC and β-glucosidase activity showing that these management factors are important for maximizing CC benefits and improving soil fertility.