Assessment of impact of foliar, neem and micronutrient-coated urea fertilizers on sustainable soil health in soils of Northern Guinea Savannah Zone of Nigeria

Abstract

Intensive agricultural practices and the continuous use of conventional nitrogen fertilizers had led to significant soil degradation, threatening long-term food security in the Northern Guinea Savannah Zone of Nigeria. The research compared the effects of foliar, neem-coated, and micronutrient-coated urea fertilizers on key soil physicochemical properties, nutrient dynamics, and nitrifying bacterial population over two consecutive cropping seasons. A Randomized Complete Block Design (RCBD) was used to establish experimental plots at two distinct locations within the zone. Soil samples were collected before and after each cropping season to analyze parameters including soil pH, organic carbon, total nitrogen, available phosphorus, and micronutrient concentrations (zinc, manganese, boron and copper). The study also evaluated changes in soil microbial biomass and activity as crucial indicators of soil health. Preliminary findings suggest that the application of coated urea fertilizers, particularly neem and micronutrient-coated variants, significantly improved soil organic carbon and total nitrogen content, while enhancing the availability of key micronutrients. These results indicated a more efficient nutrient use system that mitigates leaching and provides a slow, steady release of nutrients as well as low population of nitrifying bacteria. The study concludes that the use of coated urea fertilizers offers a more sustainable approach to maize cultivation by not only boosting yield but also by contributing to the long-term improvement of soil health in the region.