Soil physical properties, processes and associated root-soil interactions

Abstract

The soil is the most upper part of the vadose zone, subject to fluctuations in water and chemical content by infiltration and leaching, water uptake by plant roots, and evaporation from the soil surface. It is the most dynamic, as changes occur at increasingly smaller time and spatial scales when moving from the groundwater towards the soil surface. Scientists are becoming increasingly aware that soils makeup a critically important component of the earth's biosphere, not only because of their food production function, but also as the safekeeper of local, regional, and global environmental quality. For example, it is believed that management strategies in the unsaturated soil zone will offer the best opportunities for preventing or limiting pollution, or for remediation of ongoing pollution problems. Because chemical residence times in ground water aquifers can range from a few to thousands of years, pollution is often essentially irreversible. Prevention or remediation of soil and groundwater contamination starts, therefore, with proper management of the unsaturated zone. This includes the consideration of plants and trees.