Chapter 8 Soil Analysis: Physicochemical Properties

Abstract

Soils are essential non-renewable natural resources on the earth’s surface due to their extremely slow physical, biological and chemical weathering processes [1]. Soils are different across the world based on five major soil formation factors, namely parent material (e.g. rocks, sediments in the surface waters, volcanic ash, glacial tills, and organic matter), climate (e.g. temperature and rainfall), organisms (e.g. animal inhabitants, vegetation, and humans), topography or landscape (e.g. slope configuration and elevation above mean sea level), and time (e.g. lost, add, and transformation of soil components) [2]. As such, soils are living and dynamic environments with an understanding of soil characteristics that are important for different land use activities ranging from optimal agricultural production to waste disposal and land reclamation [3]. Soil physicochemical properties are key determinants of soil quality, plant growth and productivity [4]. Soil physical properties include texture (the proportion of sand, silt, and clay), colour (an indicator of drainage characteristics), structure (arrangement of soil particles into aggregates), porosity (pores or spaces within and between aggregates), and bulk density (an indicator of soil compaction) are good indicators for the root penetration, oxygen availability, and water mobility in soils [5, 6, 7]. Soil chemical properties including soil reaction (pH), nutrient availability, mineral solubility, and cation exchange capacity are important in planning fertilisation and fertigation [8].