The effect of plantation silviculture on soil organic matter and particle-size fractions in Amazonia

Abstract

SUMMARYEucalyptus grandis and other clonal plantations cover about 3.5 million ha in Brazil. The impacts of intensively-managed short-rotation forestry on soil aggregate structure and Carbon (C) dynamics are largely undocumented in tropical ecosystems. Long-term sustainability of these systems is probably in part linked to maintenance of soil organic matter and good soil structure and aggregation, especially in areas with low-fertility soils. This study investigated soil aggregate dynamics on a clay soil and a sandy soil, each with a Eucalyptus plantation and an adjacent primary forest. Silvicultural management did not reduce total C stocks, and did not change soil bulk density. Aggregates of the managed soils did not decrease in mass as hypothesized, which indicates that soil cultivation in 6 year cycles did not cause large decreases in soil aggregation in either soil texture. Silt, clay, and C of the sandy plantation soil shifted to greater aggregate protection, which may represent a decrease in C availability. The organic matter in the clay plantation soil increased in the fractions considered less protected while this shift from C to structural forms considered more protected was not observed.

Effects of erosion and deposition on particle size distribution of deposited farmland soils on the chinese loess plateau

“…PSD throughout the DF is strongly related to the ease of tillage and improvement of capillary conductivity, available moisture, permeability, agricultural development, and to saturated hydraulic conductivity and other soil physical properties (Henderson et al, 2005;Beldini et al, 2009;Tavares et al, 2010). Studies on this topic improve our understanding on what kind of particle size was retained in the DFs as a result of human interventions against soil loss.…”

Fertilização em <em>Eucalyptus dunnii</em> Maiden no bioma Pampa - Brasil

“…Knowledge about the effects of fertilization on soil productivity and nutrient stocks, especially in short-rotation stands, is essential to define conservation practices (LEITE et al, 2010). In long-term, soil sustainability and productive capacity reflect the soil organic matter maintenance and availability of nutrients via fertilizer, especially in sites with low natural fertility of the soil (BELDINI et al, 2009). Studies prove the importance of fertilization management in forest stands.…”