Growth, mineral nutrition, and physiological parameters of Eucalyptus urophylla cultivated in soils with different nutrient reserves

Abstract

Knowledge on the plant s nutrient use efficiency and physiological processes is important and can aid in choosing the species, as well as in the forest management for each soil and region. This study had the objectives of evaluating the initial growth, nutrition and physiological aspects of eucalypt cultivated with and without the addition of mineral sources of potassium (K), calcium (Ca), and magnesium (Mg). The study was performed in the Universidade Federal de Lavras (UFLA) with soils obtained from forest sites located at the geomorphologic provinces of the Peripheral Depression on the Sul-Riograndense shield and Coastal Plain of Rio Grande do Sul, Brazil. Growth variables, nutritional aspects, photosynthetic rate (A) and transpiration rate (E) of plants grown in distinct soils were evaluated under controlled conditions. Plants cultivated in soils presenting larger reserves and availability of K, Ca, and Mg, showed similar height (H), stem diameter (SD) and shoot dry matter (SDM), both with and without fertilization with K, Ca, and Mg. Conversely, plants cultivated in soils deprived of these nutrients presented substantial improvement in these attributes in the fertilized samples of these soils. Plants presented higher leaf content and accumulation of K in all soils fertilized with K, Ca, and Mg. However, overall K use efficiency was superior in plants cultivated in soils without fertilization. Similar results with and without fertilization in soils with larger mineral reserves demonstrate the importance of understanding soil and plant properties in order to optimize fertilization practices.