Cover crop residues effect on soil structural stability and phosphatase activity
Gheorghe Stegarescu, Endla Reintam, Tõnu Tõnutare
Abstract
Good soil aggregate stability and soil enzyme activity are strictly necessary for the proliferation of plants growth and soil resistance against erosion. In this study, the goal was to investigate the effect of different cover crops on the soil aggregate stability and soil phosphatase and their relationship. A laboratory pot experiment was established in which four cover crops were grown (Secale cereale L., Fagopyrum esculentum L., Brassica napus L. and Hordeum vulgare L.) for 33 days in sandy loam soil. Afterwards, the above-ground biomass was cut and incorporated in equal quantities (0.2 g C kg–1 of soil or 176 kg C ha–1) in the same soil and incubated for 30 days. The soil aggregate stability increased significantly with barley before harvesting and rye at day 30 after cover crop residues incorporation. The cover crop plant growth did not influence the soil acid phosphatase activity (APA) before biomass harvesting. Instead, the cover crop residues increased the soil APA only for a short period. The negative correlation between soil aggregate stability and APA can be explained by the variability in soil moisture. While the low cover crop residue quantity might have not been sufficient to increase and maintain the microbial activity.