Role of Soil Fertility in Influencing Nutritional Quality of Indigenous Browse Species in Mixed Crop–Livestock Systems

Abstract

Indigenous browse species represent an underutilized feed resource for livestock in tropical systems; however, their nutritional quality and its relationship with soil fertility remain poorly understood, particularly in the Caribbean region. In Guyana, limited information exists on how soil conditions influence the nutritional composition of locally available browse species, constraining their effective utilization in livestock feeding systems. This study evaluated the nutritional quality of eleven indigenous browse species and examined their relationship with soil properties in the Linden area of region 10, Guyana. Leaf samples were analyzed for proximate composition and mineral content, while soil physicochemical characteristics at collection sites were also assessed. Significant interspecific variation (p < 0.001) was observed for all proximate parameters and for sodium and zinc among mineral parameters, while calcium and potassium showed no significant differences among species (p > 0.05). Crude protein ranged from 186,400 mg/kg (18.64%) in Carica papaya to 281,200 mg/kg (28.12%) in Manihot esculenta, while crude fibre varied widely, with the highest values recorded in Pueraria montana. Principal component analysis explained 44.86% of total variance, with the first principal component (PC1) accounting for 26.12%, highlighting clear separation among species based on their nutritional traits. Soils were slightly acidic (pH 5–6) with variable organic matter and nutrient availability, and soil physicochemical properties particularly pH, organic matter content, and cation exchange capacity were found to influence the mineral composition of browse foliage across collection sites. Among the species evaluated, M. esculenta, Gliricidia sepium, and Ipomoea batatas exhibited the highest crude protein concentrations, while Colocasia esculenta recorded the highest mineral content, supporting their potential as supplementary feed resources for livestock. These findings highlight the importance of soil–plant interactions in determining the feed quality of indigenous browse species and support their strategic use as sustainable supplementary feed resources in tropical livestock production systems.