Yield parameters and water productivity of tropical and overseeded winter forages

Intensive pasture exploitation with tropical forages is one of the most efficient forms ruminant production. However, the results depends on the knowledge about these forages and the experience in its management. The objective of this work was to evaluate water productivity (WP) and yield parameters of Megathyrsus maximum cv. Mombaça “Guinea grass” and Cynodon spp. “Bermuda grass”, in single culture and overseeded with oats + ryegrass in autumn/winter period. Irrigation management was done considering a depletion factor of 0.3 (70% of the humidity the field capacity). The experimental design was a randomized complete block design with four replications, in which the forages are the treatments with evaluation at the time of the cycles. For all evaluated parameters, the best results were obtained with the Guinea grass in exclusive cultivation. The TFP (Total Forage Productivity) of Guinea grass was superior to Bermuda grass (59.3 and 30.2 Mg ha-1, respectively), in accordance with its average LAI (Leaf area index) values of 4.8 and 2.5, respectively. The most efficient use of water occurred for Guinea grass in exclusive cultivation, and the intercropped crops did not present increases in the WP. In the autumn/winter period, the accumulated TFP of the exclusive crop of Guinea grass was higher than the other crops. However, the SDM of Bermuda grass was higher than the other crops. In winter, the highest LAI occurred in Guinea grass in exclusive cultivation, followed by the overseeded Guinea grass, 4.8 and 4.5, respectively. Consortia did not increase forage yield during the winter. The consortiums did not increase forage yield during the winter.