Effects of cutting time and nitrogen fertilization on forage yield and quality of a sorghum sudangrass hybrid

Abstract

Sorghum-Sudangrass (Sorghum bicolor x Sorghum sudanense) Pioneer 988 grown in Western Turkey was cut at two phenological stages (at booting and milky-waxy ripeness stages) and at four nitrogen levels (0, 75, 150 and 225 kg N $ha^{-1}$ ) in 1995. Green forage, dry matter and ash yields increased as cutting time was delayed, whereas the yield of crude protein decreased. Delaying the cut increased the dry matter content, whereas decreased crude protein and ash contents. Plant height was greater at the time of the second cut. The green yield and dry matter were increased by up to 150 kg N $ha^{-1}$, crude protein and ash yields increased up to 75 kg N $ha^{-1}$ ; the differences observed in protein and ash contents were not significant. Total fresh green forage yield over 3 cuts were 178.8 and 170.8 t $ha^{-1}$ for 150 kg N $ha^{-1}$ and milky-waxy ripeness stage respectively.