Nitrogen, Phosphorus and Potassium (NPK) Content of Termite Mound Soils across Guinea and Sudan Savannah Zones: Implications for Soil Fertility in Bauchi State, Nigeria

Abstract

Termite mounds are ecologically important nutrient repositories in tropical African ecosystems, yet their specific contributions to nitrogen (N), phosphorus (P), and potassium (K) availability across contrasting ecological zones of Nigeria remain understudied. This study determined the NPK content of mound soils from two field-designated termite taxa, provisionally recorded as Nasutitermes cf. walkeri and Coptotermes cf. acinaciformis (with identities based only on field morphology and not yet confirmed taxonomically; see Limitations), and adjacent control soils collected from nine communities across Bogoro (Guinea savannah), Bauchi (transition zone), and Katagum (Sudan savannah) LGAs of Bauchi State. Total nitrogen was determined by Kjeldahl distillation, phosphorus by colorimetry, and potassium by flame atomic absorption spectrophotometry. Mounds provisionally designated N. walkeri at Wuntin Dada, Bauchi LGA, recorded the highest nitrogen (0.252%), phosphorus (105.97 mg/kg), and potassium (2.72 Cmol/kg). Control soils at Federal Lowcost, Katagum, showed elevated N (0.098%) and P (25.27 mg/kg), a pattern consistent with possible nutrient redistribution from adjacent mound structures, although land-use history, manure inputs, and other site-specific factors cannot be excluded. ANOVA indicated no statistically significant differences (p > 0.05) between mound and control soils at most sites; this finding should not be interpreted as evidence of active equilibration and may reflect limited statistical power associated with incomplete replication (see Limitations). These preliminary results indicate that termite mound soils warrant further investigation as potential nutrient sources for low-input cropping systems in northern Nigeria, subject to taxonomic confirmation and fully replicated sampling.