Polímero hidrorretentor e fertilização mineral na implantação de espécies florestais

Abstract

Forest productivity is influenced, among other factors, by water and nutritional availability. The use of hidrorretentor polymers is an alternative for water supply in the initial period of development of plants, and can retain and make available the nutrients present in them. These, in turn, face a scenario where most Brazilian soils have little natural fertility, are available mainly through mineral fertilization in forest stands. Therefore, the general objective of this work was to verify the effect of the use of hidrorretentor polymer and mineral fertilization on the growth of forest species in the implantation phase. In a first experiment the effect of the use of the polymer and different combinations of mineral fertilization doses on the growth of Eucalyptus urophylla x E. grandis hybrid seedlings was analyzed, in addition to analyzing the content and accumulation of nutrients of the leaves of the seedlings. In a second experiment the effect of polymer and fertilization on growth, survival and nutrient content of Toona ciliata seedlings was analyzed. Already in a third experiment the effect of the hidrorretentor polymer and doses of phosphate mineral fertilization on the growth of Pinus caribaea and Pinus elliottii were verified. From the analysis of the data it was verified that there was no interaction between the factors analyzed in the experiments. The use of the polymer influenced the growth of the Eucalyptus urophylla x E. grandis hybrid seedlings and the survival of the Toona ciliata seedlings, without influencing the growth of the pine species. The higher fertilizer dosage used was responsible for the greater growth of the seedlings, besides obtaining greater accumulation of nutrients in the hybrid seedlings. Phosphorus was shown to be a nutrient limiting the growth of Eucalyptus urophylla x E. grandis and Toona ciliata seedlings, without influencing the growth of Pinus species. The species Pinus caribaea showed higher growth in the period evaluated in comparison to P. elliottii.