Soil density by pedotransference in different soil classes of agroforestry systems in the Southwestern Amazon

Abstract

Methodology are important for different soil density classes for different land use categories and systems are important for individual use parameters. However, this parameter is often expensive, from operational, financial and time invested aspects. Pedotransfer equations can be used to estimate soil density and consequently soil carbon stock, as they are easy to apply for the use of physical and chemical attributes obtained with greater ease. This work was carried out with the objective of evaluating and comparing the PTF equation developed by Benites et al. (2007), to estimate soil density with the direct method of obtaining soil density (Volume Ring) in different agroforestry systems at 28 years of age and adjacent native forest, in three classes of soil: Entisols Plinthic (FTd), Ultisols (PVAd) and Oxisols (LVd), in a country road called Baixa Verde, Nova California (Rondônia state, Brazil). In each area, an 1 x 1.5 x 1.5 m trench was opened to profile description, soil classification and to collect soil samples. In the trench the soil was collected at six depths of 0-10, 10-20, 20-40, 40-60, 60-80 and 80-100 cm. The soil density was calculated using the volumetric cylinder method (MAV) and estimated using pedotransfer (PTF) equation proposed by Benites et al. (2007). The estimated soil density by PTF did not vary compared to that obtained by MAV, up to 20 cm depth.