Efeito do método de preparo do solo, em área de reforma, nas suas características, na composi??o mineral e na produtividade de planta??es de Eucalyptus grandis

摘要

Tillage system is a silvicultural technique used to increase water and nutrient availability for forest plantation establishment. Low intensity techniques have been recommended in recent years. However, under certain conditions more intensive soil preparation is required. This paper reports the effect of four methods of soil tillage systems on the physical and chemical properties and biomass production and mineral composition of Eucalyptus grandis plantation. The treatments applied were: T1 ) slash burning + blade + sub soiling; T2 ) slash burning + blade; T3) slash burning and T4 ) unburnt. In all cases, eucalypt seedlings were planted in a hole of 20 × 20 × 20 cm. The previous plantation had been conducted by coppicing and the trees harvested three times. The soil was a Red Latosol (Oxisol) located in Santa Barbara, Minas Gerais, Brazil. At the age of 38 months, the largest total biomass (81.6 t/ha) was measured in treatment T1 , decreasing as site preparation intensity was reduced. The lowest yield (50.4 t/ha) was observed in treatment T4 . However, the soil under this treatment presented the best chemical characteristics and the largest amount of forest floor, thus favoring forest yield sustainability due to a smaller nutrient removal.