Influence of N fertilizing on Single-cut Sorgum × Sudangrass Hybrids’ Forage Yield and Nutritive Profile

Abstract

The study aimed to observe the effects of two forage sorghum hybrids and different nitrogenous (N) fertilizer rates. The current study was set up in randomized complete block (RCB) as a split-plot design with triplicate at the Field Crops Department experimental area, University of Ankara in the 2022 summer season. This experiment included two treatments which had forage sorghum hybrids (Hay day and Super-graze) and nitrogen fertilization rates in the form of 18% ammonium sulfate [control group with no nitrogen (N0), 120 kg ha-1 N (N1), 180 kg ha-1 N (N2)]. N fertilizing rates positively influenced in agronomic profiles, yield components and nutritive profiles. The plant height (197.24-221.72 cm), green herbage yield (GHY) (60.42-70.89 ton ha-1), dry matter (DM) yield (17.77-23.98 ton ha-1), crude protein (CP) yield (0.97-1.90 ton ha-1), metabolic energy (ME) yield (33070.17-51840.85 Mcal ha-1), net energy production (NEp) yield (21164.91-33178.15 Mcal ha-1) increased with applied N rates. The maximum of DM (33.83%), CP (7.90%), TDN (58.63%), ME (2.16 Mcal kg-1 DM), NEp (1.80 Mcal kg-1 DM), and the minimum of ADF (33.09%), NDF (53.17%), ADL (5.14%) were obtained in N2 rates. In light of the results; “Hay-day” had more GHY. “Sugar-graze” had more DM yield and it was determined more digestible forage. It was inferred that the best yield components and nutritive profiles were obtained in N2 rate.