Tilth (Agriculture Glossary)

Tilth : The physical texture, structure, and general condition of soil with respect to its suitability for planting or growing a crop, as indicated by parameters such as moisture content, aeration, soil aggregate stability, rate of water infiltration, and drainage. Soil with good tilth has large pore spaces allowing air and water movement, yet is also capable of holding water and plant nutrients for substantial periods of time. The primary objective of tillage is to improve tilth by mechanical manipulation of the soil, with the goal of increasing crop yield; fertilization, irrigation, and soil amendments can also positively impact tilth. When applied excessively, however, these practices may have the opposite effect, causing the soil to lose its structure and become compacted.