PROXIMATE COMPOSITION OF Sorghum bicolor (L.) Moench. AS INFLUENCED BY DIFFERENT SUBSTRATES AND RATES OF FERTILIZER APPLICATION IN A SOILESS FARMING SYSTEM

Abstract

ABSTRACT The study was conducted to evaluate the effect of different substrates and fertilizer application rates on the proximate composition of Sorghum bicolor. A 3 × 3 factorial design was used, consisting of nine treatment combinations with four replicates, resulting in a total of 36 bags. The design included three fertilizer application rates (0, 120, and 240 kg N ha⁻¹) and three substrate levels (coco peat, rice husk, and grow mix). Results showed that S. bicolor harvested from grow mix-filled bags recorded the highest values for ether extract (EE) and ash content (5.19% and 7.66%, respectively), while the lowest values for EE and ash content were observed in S. bicolor harvested from coco peat-filled bags (4.05%) and rice husk-filled bags (7.14%) respectively. Unfertilized bags had the highest dry matter (DM) content (93.5%), whereas the lowest DM content (93.12%) was recorded for bags fertilized at 120 kg/ha. Additionally, bags fertilized at 120 kg/ha had the highest EE content (4.93%), while the lowest (4.04%) was observed in bags fertilized at 240 kg/ha. In conclusion, the type of substrate and fertilizer application rate significantly influence the proximate composition of Sorghum bicolor. Grow mix as a substrate and moderate fertilization (120 kg/ha) appear to optimize the nutrient content, particularly EE and DM.