Morfogênese de Megathyrsus maximus cv. Mombaça submetido a aplicação de lithothamnium calcareum e doses de fósforo

Abstract

Amazonian soils have low natural fertility, low levels of phosphorus and problems with acidity as natural characteristics. Correcting soil acidity and replacing nutrients via fertilizers increases soil fertility and provides an ideal environment for forage production. Therefore, the objective of this work was to understand and analyze the effects of the application of Lithothamnium associated with phosphorus doses on Megathyrsus Maximus cv. Mombasa. The experiment was conducted from December 2019 to March 2021 in the experimental area of the Universidade Federal do Sul e Sudeste do Pará, in the city of Marabá-Pará. The experiment was conducted from December 2019 to March 2021 in the area of the Federal University of the South and Southeast of Pará, in the city of Marabá-Pará. The morphogenic, structural and productive parameters were analyzed, having as evaluation period 5 productive cycles, being them leaf elongation rate, leaf appearance rate, phyllochron and leaf growth rate. There was no effect of phosphorus doses on the morphogenic components of Mombasa grass. This result was associated with soil granulometry in the region where the experiment was implemented. The results of the application of Lithothanium were not significant with doses of Phosphorus (P), but it was possible to observe in the chemical analyzes of the soil that the treatments that did not receive application of Lithothanium presented a greater amount of aluminum (Al) and a great drop in the contents of calcium (Ca) and magnesium (Mg), which confirms its potential as a soil acidity corrector. Therefore, the use of Lithothamnium as a conditioner for phosphate fertilization in pastures in sandy soil conditions was not effective. In the southeastern region of Pará, the biggest limiting factor in forage production is the rainfall that is concentrated in large amounts in the short term, which can cause losses by leaching.