Biochar from Acai agroindustry waste: Study of pyrolysis conditions.

The production chain of Acai (Euterpe oleracea Mart) has a high economic representativeness in the Brazilian Amazon. However, wastes generated from the processing of the fruit has been deliberately discarded in the environment, causing health risks to the population due to environmental contamination or the proliferation of disease agents. Thus, the production of biochar arises as an alternative to the irregular disposal of these residues. The objective of this work was to evaluate the conditions (temperature and residence time) to produce biochar from Acai processing residues and its potential for use as soil conditioner in the Amazon region. Acai seeds were carbonized using the process of muffle pyrolysis at different temperatures and residence times. Biochars were evaluated for their physical and chemical properties and hydrophobicity. The temperature had a greater influence than the residence time for most parameters. Higher values of pH, higher recalcitance and greater potential for water retention were observed for the biochar produced at temperatures of 600 and 700 °C. At lower temperatures (300 and 400 °C), a greater yield was observed, however, in this condition, the material presented an extremely hydrophobic character. By considering the favorable agronomic characteristics of biochar, the temperature of 600 °C and residence time of 60 min are the most suitable conditions for the production of biochar from Acai seeds.

Least limiting water range for oil palm production in Amazon region, Brazil

In areas cultivated with oil palm, typically mechanized field operations using heavy vehicles may negatively affect soil physical properties and productivity. The aim of this study was to evaluate soil physical quality in an area cultivated with oil palm by monitoring the temporal variation of the soil water content and relating it to the critical limits of the least limiting water range. Soil bulk density (Bd), soil penetration resistance (SR), least limiting water range (LLWR), and water stress days (WSD) were used to assess soil physical quality in planting rows (PR) and the traffic zone (TZ) at depths 0-20, 20-40, and 40-60 cm. The Bd was higher and the LLWR was reduced in TZ only at the surface layer. The effect of temporal variation in soil water content on the soil physical quality was higher in TZ, mainly in subsurface layers. Bd and LLWR did not affect the fresh fruit bunch production; however, WSD in TZ at 20-40 and 40-60 cm layers provided evidence of effects of temporal variation of soil water content on oil palm productivity.(AU)

Least limiting water range for oil palm production in Amazon region, Brazil

In areas cultivated with oil palm, typically mechanized field operations using heavy vehicles may negatively affect soil physical properties and productivity. The aim of this study was to evaluate soil physical quality in an area cultivated with oil palm by monitoring the temporal variation of the soil water content and relating it to the critical limits of the least limiting water range. Soil bulk density (Bd), soil penetration resistance (SR), least limiting water range (LLWR), and water stress days (WSD) were used to assess soil physical quality in planting rows (PR) and the traffic zone (TZ) at depths 0-20, 20-40, and 40-60 cm. The Bd was higher and the LLWR was reduced in TZ only at the surface layer. The effect of temporal variation in soil water content on the soil physical quality was higher in TZ, mainly in subsurface layers. Bd and LLWR did not affect the fresh fruit bunch production; however, WSD in TZ at 20-40 and 40-60 cm layers provided evidence of effects of temporal variation of soil water content on oil palm productivity.