Assessment of Crop Residue Management Practices and Their Effect on Soil Fertility in Kogi State

This study assesses crop residue management practices among farmers in Kogi State, North Central Nigeria, and examines their effect on soil fertility indicators. Crop residues returned to the soil after harvest contribute organic matter, nutrients, and beneficial microbial activity, but their management varies widely among farmers from burning and removal to incorporation and surface retention. Kogi State's diverse farming systems including maize, cassava, and yam generate substantial residue volumes that represent an underutilised soil fertility resource. This study uses a survey of 180 farmers in Lokoja, Kabba-Bunu, and Yagba East local government areas to document residue management practices, followed by soil sampling from farms with contrasting management practices. Soil organic matter, available phosphorus, total nitrogen, and microbial biomass carbon are measured in farms with five years or more of consistent residue burning, incorporation, or surface mulching practices. Descriptive statistics and ANOVA are applied. Findings reveal that 62 percent of sampled farmers burn crop residues, citing ease of field clearing and pest control. Farms with residue incorporation history show 42 percent higher soil organic matter and 28 percent higher total nitrogen compared to residue-burning farms. Surface mulching shows intermediate soil fertility outcomes. The study concludes that residue burning is the dominant but agronomically inferior practice in Kogi State. It recommends farmer training on residue incorporation and composting as priority soil fertility management interventions.

Keywords: crop residue management, soil fertility, organic matter, Kogi State, residue burning.