Effects of nitrogen fertilizer application rate on desho grass (Pennisetum glaucifolium) herbage yield and nutritional compositions across harvest days

Abstract

This study evaluated the effect of nitrogen fertilizer application rates on desho grass (Pennisetum glaucifolium) morphology, dry matter accumulation and nutritive values across three harvests. The experiment was conducted in a randomized complete block design with 0, 50, 100, and 150 kg ha-¹ nitrogen (N) rates across 90, 120, and 150 days of harvests. Average plant height (PH), number of tillers per plant (NTPP), number of leaves per plant (NLPP), and leaf length per plant (LLPP) were recorded. Leaf-to-stem ratio (LSR), fresh forage mass (FFM), dry matter accumulation (DMA), and nutritional contents were assessed. Average PH, NTPP, NLPP, LSR, and DMA were significantly higher across N rates and harvest days. The interaction effect was significant for LLPP and FFM. At 150 kg ha-¹, the highest DMA value was recorded at 150 days, whereas crude protein (CP) content, in-vitro dry matter digestibility (IVDMD) and metabolizable energy (ME) were at 90 days of harvest. N rates and harvest days had a significant effect on phosphorous and calcium contents. However, higher acid detergent fiber (ADF), neutral detergent fiber (NDF), and acid detergent lignin (ADL) values were obtained with low fertilizer rates and later harvests. Therefore, greater than 100 kg ha-¹ N rates and above 100 days of harvest resulted in higher DMA, CP, IVDMD, and ME of desho grass, which should be recommended to obtain feed with optimum nutritional value.
Keywords: Crude protein, Desho grass, Dry matter accumulation, Metabolizable