Dynamic of soil macrofauna in organic cotton cropping under agroecological practices in the North Sudanese zone of Burkina Faso

Abstract

Low application of organic matter on soils under cotton cultivation has a negative impact on soil macrofauna installation, a major component of soil fertility. Zaï, a soil fertility management practice, can be explored to improve soil macrofauna under organic cotton cultivation. The study’s objective was to characterize the effects of zaï and ploughing on soil macrofauna in the North Sudanese zone of Burkina Faso. A completely randomized Fisher block design with seven treatments including L0 (ploughing without compost), L1 (ploughing+1 t/ha of compost), L5 (ploughing+5 t/ha of compost), Z1 (zaï+1 t/ha of compost), Z2.5 (zaï+2.5 t/ha of compost), Z3 (zaï+3 t/ha of compost), Z5 (zaï+5 t/ha of compost) was studied. Macrofauna sampling was carried out using the standard TSBF method. Results showed that macrofauna composition was dominated by Termitidae (66.3%), Formicidae (16.4%) and Octochaetidae (5.7%). Treatments L5 and Z5 showed the highest densities, with 29.1% and 28.2% of the population respectively. As for trophic groups, saprophagous represented 81.96%, compared with 7.71% geophagous, 5.69% phytophagous and 4.64% predatory. Treatment Z1 was favorable to the installation of beneficial groups (saprophagous, geophagous, predators) compared with treatments Z2.5, Z3, L1 and L0. The treatment Z1 can be vulgarized to improve the biological fertility of soils in this context of low availability of organic manure.