ABSTRACT
Soil is a medium for plant growth, and its structure should not hinder the movement of water, oxygen and nutrients to plant roots, impede the growth of roots, or allow the buildup of toxic substances around roots. Soil structure can be described as the organization of the particles in the soil-the internal configuration of the soil matrix (1). Soil structure is formed by many interacting processes in the soil, especially shrinkage with drying, channel formation by plant roots, faunal activity, and cultivation (2). Well-developed soil structure is represented by distinct stable aggregations (peds) of soil particles separated by interped pores. The interped pores of an aggregated soil are larger, on average, than pores between particles of unaggregated soil, resulting in a less dense condition. The larger pores are also critical in terms of allowing movement of air and water through the soil. Unfavorable soil structure, on the other hand, can impart the characteristics of greater soil density, decreased aeration, poor percolation, and mechanical impedance to roots, which can restrict plant growth (3).
