A exigência em nitrogênio do capim Mulato II assemelha-se a U. brizantha ou U. decumbens?

Abstract

Mulato II grass (Urochloa hybrid cv. Mulato II), marketed as Convert HD364, is a hybrid obtained from the cross between Urochloa ruziziensis x Urochloa decumbens x Urochloa brizantha by the International Center for Tropical Agriculture. This grass is not present in several fertilizer recommendation bulletins and, therefore, there is a need to frame it so that sustainable pasture fertilization management can be carried out. Thus, through model identity tests, the objective was to identify whether the response to nitrogen fertilization of Mulato II grass resembles the response of Marandu (U. brizantha cv. Marandu) and Decumbens (U. decumbens cv. Basilisk) grasses, as they are parents of different soil fertility requirements. The experiment was carried out in a greenhouse of the Federal University of Mato Grosso, Rondonópolis University Campus. A completely randomized design with a 3x5 factorial scheme (three grasses and five nitrogen doses) was used, with fifteen treatments and four replications. Three evaluative cuts were made, so that the first cut was called implantation and the average of the other cuts was called regrowth. The results were submitted to linear and quadratic regression analysis and, if significant, the F test was used to compare the models. In case of different models, the F test was performed to compare intercepts and parameters of the equations. In the implantation phase Mulato II grass is very similar to Marandu grass, differing only in crude protein, and crude protein of leaf blade. This similarity is confirmed in the regrowth phase, when Mulato II grass resembled Marandu grass in all analyzed variables. In the implantation and regrowth, Mulato II grass distinguished from Decumbens grass for most of the analyzed variables. Thus, the nitrogen requirement of Mulato II grass is similar to U. brizantha cv. Marandu.