Soil-traits interactions, path analysis of growth and fertility indicators driving sugarcane (Saccharum officinarum) yield in the Nigerian Southern Guinea Savanna

Optimizing sugarcane yield under variable soil conditions requires a deep understanding of the interactions between plant traits and soil fertility parameters. This study investigated the direct and indirect contributions of key growth attributes and soil properties to sugarcane (Saccharum officinarum L.) yield in the Southern Guinea Savanna of Nigeria. Field trials were conducted at Badeggi during the 2018 and 2019 rainy seasons. Growth parameters, including stalk height, stalk girth, and Brix content and soil fertility indicators (organic carbon, total nitrogen, and available phosphorus) were measured and analyzed using correlation and path coefficient analysis. Cane yield showed strong positive correlations with stalk height, stalk girth, and soil organic carbon across both seasons. Path analysis identified stalk girth (31.6% in 2018; 19.1% in 2019) and stalk height (7.5% in 2018; 19.3% in 2019) as the most influential direct contributors to yield. Soil nutrients and Brix content contributed indirectly, primarily through their enhancement of structural growth traits. The analytical model accounted for 71.2% and 80.4% of yield variability in 2018 and 2019, respectively. These findings underscore the pivotal role of stalk morphology and nutrient-enriched soils particularly organic carbon and phosphorus in driving cane yield. The results advocate for an integrated approach that combines varietal selection for structural vigor with site-specific nutrient management to sustainably enhance sugarcane productivity in savanna agroecosystems.