Essay On Hydrophobicity

ABSTRACT

INTRODUCTION

Water is the most precious resource in agricultural practices and without it plant growth would be hindered and soil would become bare and dry. Soil needs to be hydrophilic in order to accommodate activities that should occur in the soil. Unfortunately some soils repel (hydrophobic) water and therefore temper with their function of acting as a medium of these agricultural activities. Soil hydrophobicity is when water does not infiltrate but rather collects on the soil surface. Soils are generally considered to be readily wet when irrigated or when there is rainfall. This does not happen in hydrophobic soils because there is reduced affinity for soils to water in such a way that wetting and infiltration occurs slowly. This may take seconds to weeks depending on how the affinity strength is damaged. Soil hydrophobicity is said to be caused by a coating of long-chained hydrophobic waxy organic molecules on individual soil particles. These organic molecules may be released from

Hydrophobicity in no till can enhance soil structure development (Eynard et al., 2006), soil organic C sequestration (Bachmann et al., 2008; Blanco-Canqui & Lal, 2009; Lamparter et al., 2009; Simon et al., 2009) and reduction in soil erodibility (Eynard et al., 2006). No till soils have shown (through studies) to have high wet aggregate stability, macroposity and soil organic C pools. These advantages may be partly caused by the hydrophobicity in no till system. Also, the slow infiltration may be beneficial for reducing crumbling of soil aggregates. Recent studies show that soil hydrophobicity in no till soils may contribute to the stabilization of carbon inside aggregate because of reduced aggregate slaking (Lamparter et al.,