Comparative study of the nutritional constitution of wood and bark of species and clones of eucalyptus aiming the cultivation of shiitake in logs

Abstract

The nutritional properties of wood and bark of seven species and three clones of eucalyptus were evaluated, aiming the cultivation of shiitake in logs. The experimental design was totally randomized, with 10 treatments (types of eucalyptus) and 3 repetitions, being each repetition corresponding to a mixed sample of sawdust obtained from discs collected in different heights (9 cm, middle and 14 cm of diameter) from the same tree. Barks were removed from wood wedges for individual analysis. Samples were sent to the Laboratory of Chemical Analysis of Fertilizers and Correctives of the Department of Natural Resources - Soil Science - School of Agronomic Sciences/UNESP, for determination of macro and micronutrients composition. Nitrogen determination was performed by oxidation with perchloric acid; phosphorus was determined with nitric-perchloric extraction and colorimetric determination (spectrophotometric molybdovanadophosphoric acid method); potassium was determined by flame photometry; carbon, by muffle burning; sulphur, by gravimetry and calcium, magnesium, sodium, copper, iron, manganese and zinc, by atomic absorption spectrophotometry. According to the results obtained and as expected, it was verified that the element S was not detected in any of the kinds of eucalyptus analyzed, both for bark and wood; for wood, elements Mg, Na and Mn presented difference in contents among eucalyptus types analyzed. For bark, K2O, C, Cu and Mn showed different contents in function of eucalyptus type. Barks of eucalyptus types presented very high contents of Ca (77x), K (3,7x), Mg (39x), Na (2,5x), Mn (26x) e Fe (1,9x), compared to the corresponding woods (Ca was the prevailing element in bark). Ca, K, Mg and P were the prevailing elements in wood.