Optimal Time for Haymaking and Potential Production of Grass Hay on Soybean Overseeding in Brazilian Savanna

Abstract

The objective of this research was to determine the potential for hay production of Quenia guinea grass (Megathyrsus maximus cv. BRS Quenia), Congo grass (Urochloa ruziziensis), and Xaraes palisade grass (Urochloa brizantha cv. Xaraes) following soybean cultivation (Glycine max) in the Brazilian Cerrado. The experimental field was divided into 12 plots, with 4 replicates of each grass species. Chemical composition, forage mass (FM), and the potential for milk and carcass production were determined for the three grasses. Principal component analysis showed that the total digestible nutrients (TDN) had the most significant influence on milk and carcass potential. Quenia guinea grass reached maximum forage accumulation at 134 days after soybean harvest, representing 4191.51 kg ha−1 of FM. Congo grass and Xaraes palisade grass produced 4033.51 kg ha−1 and 4437.22 kg ha−1, respectively, in cuts made at 154 and 138 days. Quenia guinea grass had 20.71% soluble protein in its composition when harvested at 115 days. Regarding milk production potential, Congo grass, on the other hand, showed a linear reduction in milk production as the number of days after soybean harvest increased. As for carcass production potential, Congo grass demonstrated the highest carcass production potential (110.65 kg Mg−1 FM) at 107 cutting days. Xaraes palisade grass had the highest FM production, while Quenia guinea grass stood out in soluble protein. Conversely, Congo grass showed greater potential for hay production when overseeding in soybeans, as it excelled in carcass production potential. Therefore, for this grass, the ideal point for haymaking should occur within up to 107 days after sowing.