Theory question 104
Soil Properties(a) Explain the term soil structure and state its importance in agriculture.
(b) State four properties each of clay and sandy soil.
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(a) Soil structure is the arrangement or grouping of soil particles into aggregates (crumbs, plates, blocks, prisms); good (crumb) structure improves aeration, drainage, water holding, root penetration, microbial activity and resistance to erosion; makes tillage easier
(b) Clay: fine particles (below 0.002 mm); high water-holding capacity; poorly drained and aerated; sticky when wet, hard and cracks when dry; high nutrient-holding capacity; heavy to till
Sandy: coarse particles; low water-holding capacity, drains quickly; well aerated; low nutrients, easily leached; light and easy to till; warms up quickly
Define structure, then contrast clay and sand point by point.