Water erosion in soils under eucalyptus forest as affected by development stages and management systems

Abstract

The constant increasing of eucalyptus forest areas in Brazil requires an accurate monitoring of water erosion. The present study aimed to evaluate soil, nutrients and organic carbon losses occasioned by water erosion in eucalyptus planted forests (EPF) at different development stages (2, 3 and 7 years old). Soil erosion sediments were measured and sampled from standard erosion plots installed on Red Argisol-RA (Ultisol) and Haplic Cambisol-HC (Inceptisol). Soil loss decreased as the age of plants increased; at the beginning of plant development, the canopy barely covered the soil surface, exposing the soil to higher erosion at young EPF plantations. Furrow planting system was used in the Red Argisol area and caused higher soil losses (1.1 to 6.2 Mg ha-1 year-1) as compared to pit planting system that was used in the Cambisol area (1.1 Mg ha-1 year-1). It is known that Cambisol is less resistant to erosion than Argisol. However, using pit system in this EPF, resulted in lower erosion and, therefore, nutrients and carbon losses than the traditional furrow system used in Argisol. Concerning the soil loss, this work points to the need of improving soil conservation practices to prevent soil erosion at the earlier stages of eucalyptus plantation. The amount of calcium and potassium were higher than magnesium in the soil sediment.The relatively high amount of carbon found in the erosion sediments raises additional concerns about the environmental sustainability and deserves future research.

Erosão hídrica pós-plantio em florestas de eucalipto na bacia do rio Paraná, no leste do Mato Grosso do Sul

“…Diversos estudos têm evidenciado que ambientes com vegetação nativa apresentam menores taxas de erosão hídrica (Neary et al, 2009;Kateb et al, 2013;Oliveira et al, 2013). As menores perdas observadas nos ambientes nativos podem ser explicadas pela interceptação das gotas de chuvas pelo dossel das árvores e pela existência de uma rica serapilheira, que proporcionam maiores valores de macroporosidade e condutividade hidráulica (Quadro 2).…”

Soil cover plants on water erosion control in the South of Minas Gerais

“…The monthly soil and water losses were higher in March, followed by December, January and February, except by the soil losses for pigeon bean and the jack bean under contour seeding (Table 4), and the water losses for jack bean under contour seeding (Table 5). In March, after several months of rain, the soil is probably more saturated and has a reduced rate of water infiltration, provoking an increase of runoff; resulting in high levels of soil and water losses (OLIVEIRA et al, 2013). When studying how agroforestry systems reduce the intensity of erosive agents, Aguiar et al (2006) observed that sediments and water losses were concentrated during the end of the rainy period, due to the previous soil moisture.…”

Water erosion associated with rainfall patterns in the extreme South of Bahia in eucalyptus post-planting

“…These facts indicate the sustainability of this silvicultural exploitation and the effi ciency of the maintenance of litter to reduce soil and water losses. Oliveira et al (2013a) studied erosion in forest systems and reported that not only the species, but also the age of the plant directly infl uence soil erosion losses. Soil losses in the Spodosol area were of 0.04, 0.15, and 0.015 Mg ha -1 year -1 for Eucalyptus minimum tillage, bare soil, and native forest, respectively.…”