Response of sweet sorghum (Sorghum bicolor L. Moench) to the combined application of poultry litter and inorganic fertilizer

Abstract

Integrated nutrient management is one of the alternatives to inorganic fertilizer application to sustain ecological balance, and crop productivity and augment the cost of fertilizers. This study aimed to evaluate the response of sweet sorghum to the combined application of poultry litter and inorganic fertilizer on plant height, stalk length, stalk diameter, panicle length, panicle weight, 1,000-grain weight, and plot yield. This was conducted in a farmer's field at Cabadbaran City, Agusan del Norte, Philippines in 2021. The experiment was laid out in Randomized Complete Block Design (RCBD) with six treatments and three replications. The treatments were T 1 - No fertilizer application (control), T 2 - 120-40-45 kg ha -1 N, P 2 O 5 , K 2 O (Recommended Rate), T 3 - 5 t ha -1 poultry litter, T 4 - 90-30-33.75 kg ha -1 N, P 2 O 5 , K 2 O + 1.25 t ha -1 poultry litter, T 5 - 60-20-22.5 kg ha -1 N, P 2 O 5 , K 2 O + 2.5 t ha -1 poultry litter and T 6 - 30-10-11.25 kg ha -1 N, P 2 O 5 , K 2 O + 3.75 t ha -1 poultry litter. The combined application of poultry litter and inorganic fertilizer significantly affected the plant height, stalk length, stalk diameter, panicle length, panicle weight, and grain yield. The highest grain yield was recorded in plants applied with 3.75 t ha -1 poultry litter + 30-10-11.25 kg ha -1 N, P 2 O 5 , K 2 O inorganic (T 6 ) but was comparable with the other poultry litter + inorganic fertilizer treatments. T6 gave the highest net income and return on investment of PhP 63,327.98 and 143.72 percent, respectively. It could be concluded that growing sweet sorghum was highly profitable when applied with a combination of poultry litter and inorganic fertilizer at the rate of 3.75 t ha-1 30-10-11.25 kg ha-1 N, P2O5, K2O.