Effect of no-till and residue retention on fungal composition and population in maize-bean intercrop

Abstract

This study determined the effect of Zea mays L. and Phaseolus vulgaris L. intercrop under no-till with residue retention (Conservation Agriculture- CA) on composition and population of soil fungal species. Soil samples were collected from 64 farms, half of which had tested CA and the other half had tested Conventional Tillage (CT) for five years. Half of CA and CT farms were in Upper Midland (UM 3), the other half in Lower Midland (LM 4). Samples were analyzed for fungal microbial population, composition and soil fertility. In CT land was dug by hand held hoe and residue removed. CA resulted in increase of soil fungal populations of 56% and 113% in LM 4 and UM 3 respectively as compared to CT. Fungal species belonging to 11 genera were detected. Total fungal, Penicillium and Colletotrichum CFUs/g soil were significantly higher in CA than in CT. Soil populations of Aspergillus and Fusarium did not change significantly but their relative composition changed due to changes in soil populations of other fungal genera. Total fungal CFUs/g soil were significantly correlated to Penicillium (p ≤ 0.01) and Macrophomina (p ≤ 0.05) CFUs/g soil. There was no significant difference between CA and CT on crop diseases.

Keywords

• conservation agriculture-sustainable intensification
• maize-bean intercrop
• aspergillus
• fusarium
• fungal microbial population