Assessment of Integrated Soil Fertility Management Options for Sorghum Production in Yobe State

This study assesses integrated soil fertility management options for sorghum production in Yobe State, North East Nigeria. Soil fertility depletion is a pervasive constraint on sorghum productivity in Yobe State, where decades of intensive cultivation without adequate nutrient replacement have reduced yields far below attainable levels. Integrated soil fertility management, combining judicious use of mineral fertilisers with organic inputs and improved varieties, offers a pathway to improved productivity without the capital intensity of mineral-fertiliser-only approaches. This study establishes a randomised complete block design experiment at Yobe State University research farm testing five ISFM treatments: sole mineral NPK at recommended rate, sole cattle manure at 5 tonnes per hectare, sole Tithonia biomass at 3 tonnes per hectare, half recommended NPK combined with cattle manure at 2.5 tonnes per hectare, and half recommended NPK combined with Tithonia at 1.5 tonnes per hectare, alongside an unfertilised control. SAMSORG 14 sorghum variety is used across all treatments. Soil nitrogen and phosphorus, plant nutrient uptake, and grain yield are assessed over two growing seasons. Findings reveal that integrated NPK plus Tithonia biomass achieves the highest grain yield of 3.1 tonnes per hectare while maintaining soil nitrogen 18 percent above the mineral-only treatment. Combined NPK plus cattle manure shows the strongest soil organic carbon improvement. All ISFM treatments significantly outperform sole mineral or sole organic approaches. The study concludes that ISFM is superior to single-input approaches for Yobe State sorghum and recommends Tithonia-NPK integration as the priority recommendation for the zone.

Keywords: integrated soil fertility management, sorghum, Yobe State, Tithonia, organic manure.