The objective of this study was to evaluate the effects of two doses of
phosphate fertilization (50 e 200 kg . ha-1 P2O5) and two doses of nitrogen
fertilization (100 e 400 kg . ha-1 N) in a randomized block design in factorial
scheme 2x2+1, with one additional treatment (control), on the morphogenic and
structural aspects of the Panicum maximum cv. Massai. The treatments were
implanted in the experimental area using simple superphosphate for phosphate
fertilization and ammonium sulfate for nitrogen fertilization. Samples were
collected at a height of 15 cm from the soil, in three cycles pre and post grazing
in the grazing system rotated with 4 days of occupation and 28 days of rest. The
morphogenesis was evaluated by the marked tillers. It was evaluated the rate of
leaf emergence (TApF); leaf elongation rate (TAlF); leaf senescence rate (TSF);
And stem elongation rate (TAlC). There was difference between the control
treatment and other treatments, and effect of the interaction of the fertilizations
on the TAlF, with the best dose response (100 kg . ha-1
de N e 50 kg . ha-1
P2O5) Introducing 43,85 mm . tillers-1
. day-1
. The TAlC and TSF were not
affected by the fertilization interactions studied, there was also no difference
when compared to the control treatment. For TApF, the doses (400 kg . ha-1 N e
200 kg . ha-1 P2O5) that affected the appearance of new leaves. There was no
difference or interaction of the treatments on the number of tillers (NP). High
doses of nitrogen influenced the leaf life span (DVF). The phosphate and
nitrogen fertilization influenced the morphogenic variables of the Massai grass.
Nitrogen acts in the process of forage growth and development, while
phosphate fertilization alone has no significant effect.
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