Initial growth of fourteen native tree species in response to potassium fertilization

Abstract

An experiment was carried out under greenhouse conditions, in order to evaluate the potassium response of fourteen native tree species. The studied species, according to its ecological group were: Pioneer species: Peltophorum dubium (Spreng) Taub., Senna spectabilis (DC) I.&B. (Spreng), Senna multijuga (L.C. Rich) I.&B., Stenolobium stans (Jun.) Seem, Jacaranda mimosaefolia D. Don., Guazuma ulmifolia Lam. and Trema micrantha Bloom; Secundárias: Anadenanthera peregrina (L.) Speg., Machaerium nictitans Vell. Benth., Cedrella fissilis Vell. and Senna macranthera (Collad.) I.&B.; Espécies Clímax: Copaifera langsdorffii Desf., Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang, and Platycianus regnelli Benth. L.; Anual: Zea maiz L. A soil with 0.72 mmol_cK⁺.dm^-3 soil by Mehlich-1 was used, establishing the following treatments: without potassium (-K), and with application of 84 mg K⁺/kg soil. In both treatments, soil was previously limed and conveniently supplied with other nutrients. Differential response was observed among species and ecological groups to the potassium fertilization. With exception of cassia-carnaval (Senna spectabilis), in all other pioneer species the total dry matter production was significantly increased with potassium fertilization. In the group of secondary species, only cedro (Cedrella fissilis Vell.) and fedegoso (Senna macranthera (Collad.) I.&B.) were responsive to potassium application, while climax species did not. The highest responses were found for pioneer and secondary species with fast growth rate.