Nutritive value and herbage mass in hybrids of Paspalum plicatulum × Paspalum guenoarum fertilized with nitrogen or in mixture with temperate legumes

Abstract

AbstractRecent efforts placed on breeding Paspalum species made available novel genetic resources for livestock production systems. Nitrogen (N) is an important factor to increase warm‐season grass nutritive value and production, either as anthropogenic supply or in mixture with legumes. Dry matter yield (DMY) and nutritive value in Paspalum plicatulum Michx. × Paspalum guenoarum Arechav. hybrids in response to different rates of N or in mixture with temperate legumes were evaluated for two years. The experiment was a randomized complete block design in split‐plot arrangement with three replications. Treatments were six N supply systems: 0, 60, 120, 240, 480 kg N/ha and grass–legume mixture [white clover (Trifolium repens L.) + birdsfoot trefoil (Lotus corniculatus L.)] as whole plots, and six genotypes (hybrids: 1020133, 102069, 103084, 103061, P. guenoarum ecotype ‘Azulão’ and Megathyrsus maximus cv. ‘Aruana’ used as controls) as subplots. Higher N rates increased DMY and provided variability among genotypes. In general, grass–legume mixture showed greater crude protein and digestibility, and lower neutral and acid detergent fiber than N fertilized grass (p < .05). Hybrid 1020133 had DMY similar to Aruana and Azulão in years 1 and 2. Hybrids 103084 and 103061 exhibited higher nutritive value than Aruana and Azulão in year 1 (p < .05), and similarly in year 2. These three hybrids were identified as potential releases. Supplying N by fertilization or mixture with legumes increased DMY and improved nutritive value in Paspalum pastures.