CATTLE MANURE AND LUMBRICUS TERRESTRIS IMPROVE SOIL PROPERTIES

This study investigated the individual and combined effects of an organic amendment (composted cattle manure) and anecic earthworm activity (Lumbricus terrestris) on the physico-chemical properties of a loamy-clay soil from the coastal region Bejaia (Algeria), characterized by a sub-humid climate. A field experiment was conducted using six 1 m2 quadrats; the three containing earthworms were enclosed by metal plates (70 cm deep) to prevent migration. Treatment consisted of three manure application doses (0%, 2% and 4% organic matter) combined with two earthworm conditions (absence or presence of 100 individuals). Principal component analysis (APC) revealed a notable effect of treatments combining compost and earthworms on structure stability, permeability, porosity, moisture content, C/N ratio and pH. The combined application of 4% manure and 100 earthworms resulted in the most pronounced improvements, with permeability increasing from 0.14 to 0.83 cm h-1 and porosity from 29.07% to 54.13%. In parallel, the structural instability index decreased from 20.09 to 3.35, alongside a reduction in water content from 38.2% to 27.4%. This results suggest a complementary effect between earthworm activity and organic matter addition, contributing to sustainable agricultural practices and soil health in sub-humid regions. Longer-term experiments are needed to confirm these trends.