High-Throughput Phenotyping and Elemental Mapping Identify Biomarkers for Yield and Biofuel Purity in Sweet Sorghum

The increasing demand for sustainable biofuels necessitates high-yield, processable feedstocks; nevertheless, sweet sorghum ( Sorghum bicolor L. Moench) is underutilized due to a lack of understanding of the interactions among its morphological, physiological, biochemical, elemental, and thermal characteristics. This research employs a comprehensive, high-throughput phenotyping and multi-omics approach to identify reliable biomarkers for predicting production and biofuel quality across various fertilizer management systems. Ten treatments, comprising conventional NPK, nano-NPK, zeolite, press mud, and bio-neem, were assessed using a randomized block field design. The evaluated traits encompassed plant phenology (height, root biomass, and chlorophyll index), yield components (grain yield, ear head weight, and girth), juice quality (TSS, sucrose, purity, and ethanol concentration), elemental composition (EDX), and thermal stability (TGA). Treatment T6, which integrates 75% of the required fertilizer with zeolite (1.5 t ha⁻¹), press mud (15 t ha⁻¹), and bio-neem (5 kg ha⁻¹), consistently surpassed all other treatments, enhancing grain production by 56%, ethanol concentration by 30%, and extract weight by 74% compared to the control group. EDX indicated increased nitrogen levels and diminished trace metals, whereas TGA demonstrated improved thermal stability, with a breakdown temperature of around 294°C and a structured, multistage degradation profile. Multivariate studies (PCA, k-means, hierarchical clustering, and chord correlation) validated robust correlations of T6 with essential yield- and quality-related variables, underscoring the synergistic potential of integrated nutrition management. These findings establish a scalable framework for the early identification of superior bioenergy phenotypes and demonstrate that integrating organic amendments with reduced inorganic inputs can simultaneously enhance agronomic performance, juice quality, and biomass processability, indicating a strategic progression toward a sustainable bioeconomy.