The objective was to evaluate the potential of phosphate fertilization as a strategy to
produce a deferred pasture and to verify the potential residual effect of this
fertilization for the regrowth of Marandu grass in the next rainy season. The
experimental design used was a randomized block design with treatments arranged
in a 2 x 5 + 1 factorial, with two phosphorus sources (simple superphosphate and
Arad reactive natural phosphate) and five phosphorus doses (0, 25, 50, 75 and 100
kg ha-1
of P2O5), with four repetitions and one additional treatment without any type of
fertilization (control). The variables evaluated were: height, tiller population density,
forage dry mass, total dry mass, root dry mass, leaf: stem ratio, percentage of dead
material and percentage of soil cover. The growth and production of Marandu grass
in the deferral were benefited by fertilization and mainly by the inclusion of
phosphorus together with nitrogen and potassium (N and K2O). The single
superphosphate source was shown to be superior to Arad in benefiting forage
development at deferral. Phosphate fertilization favored the accumulation of biomass
by Marandu grass, contributing to the recovery of degraded pasture. Fertilization of
Marandu grass at deferral had a residual effect on height, tillering and forage
production at regrowth. Marandu grass showed positive responses in relation to
phosphorus sources. Arad rock phosphate can be a long-term alternative for use in
conjunction with a soluble source to supplement the supply of P2O5. Advance
fertilization with Arad improves its solubilization and forage performance in the next
rainy season.
|
