Stoichiometric Homeostasis and Ecological Stoichiometry of Nigerian Agricultural Food Webs Under Nutrient Management Regimes

This study applies ecological stoichiometry theory to analyse nutrient homeostasis in Nigerian agricultural food webs under contrasting nutrient management regimes, contributing an original theoretical contribution to understanding nutrient cycling and trophic interactions in managed agro-ecosystems. Ecological stoichiometry examines the balance of chemical elements in ecological interactions, providing a mechanistic framework for understanding how nutrient imbalances propagate through food webs from soil through plants to herbivores and decomposers. In Nigerian agricultural contexts, where nutrient imbalances from selective fertilisation and organic matter depletion are widespread, stoichiometric theory predicts cascading effects on pest, beneficial arthropod, and decomposer communities that have not been empirically tested. This study measures carbon, nitrogen, and phosphorus ratios in soil, plant tissue, herbivore pests, natural enemies, and decomposer communities across six contrasting nutrient management regimes at sites in Kwara, Kano, Enugu, and Rivers States representing major Nigerian farming systems. Stoichiometric homeostasis indices, food quality assessments, and trophic transfer efficiency measures are computed. Structural equation models test the proposed stoichiometric mechanisms linking nutrient regime to food web structure. Findings reveal that nitrogen-heavy fertilisation without adequate phosphorus creates stoichiometric imbalances in plant tissue that reduce natural enemy fitness by 28 percent and increase herbivore pest growth rates by 34 percent through improved nitrogen but reduced phosphorus food quality. The study contributes original stoichiometric agricultural food web data for Nigeria and recommends balanced nutrient management as a pest management co-benefit strategy.

Keywords: ecological stoichiometry, agricultural food webs, nutrient management, Nigeria, trophic interactions.