Productive and Nutritional Responses of Cayman Blend and Miyagui Grasses to Biofertilizers Under Warm Subhumid Conditions

Practical application rates of liquid manure-derived biofertilizers (biols) are poorly documented during tropical grass establishment. This study evaluated dry matter yield, nutritive value, and energy estimates of Cayman Blend (Urochloa hybrid) and Miyagui (Megathyrsus maximus) under bovine- and rabbit-manure biols at 400 or 800 L ha−1, chemical fertilization (60-60-00 kg ha−1 N-P2O5-K2O), and an unfertilized control. A split-plot randomized complete block design with three replicates was used. Treatments were applied once at 35 days after sowing, and grasses were harvested at 88 days. Chemical and biol treatments were not nutrient-equivalent. Grass × fertilization interactions were significant for yield (p = 0.0401) and all nutritive and energy variables (p < 0.0001). Chemical fertilization produced the greatest yields (7.38 and 7.10 t ha−1 for Cayman Blend and Miyagui, respectively). In Cayman Blend, chemical fertilization improved crude protein, digestibility, and energy estimates, whereas Bov800 improved digestibility and energy-related variables without increasing yield. In Miyagui, Rab400 and Rab800 increased yield relative to the control, while chemical fertilization reduced digestibility and energy estimates. Overall, responses depended on grass and treatment, and the tested biol rates did not match the yield obtained with chemical fertilization.