Soil texture refers to the percentage of sand, silt, and clay particles that make up soil. Sand particles are large with big pores while clay particles are small with tiny pores. Clay and humus particles give soil cation exchange capacity and improve fertility. Ideal soil structure forms stable aggregates. Primary cultivation aerates soil and incorporates organic matter while secondary cultivation firms soil into a crumb structure that supports root growth. A crumb soil structure is best for horticulture.

1. RHS Level 2 Certificate Year 2 Week 2 – Soil Texture, Structure and Cultivation

4. Soil particle sizes

6. Sand: big particles, big pores. Clay: little particles, tiny pores.

7. Small particles, enormous surface area. Big particles, small surface area.

12. Characteristics of soil types The best of all worlds. Structure is easily worked into crumb aggregates. Good CEC combined with good drainage and water holding capacity. Easy to work. Loam Quick to warm and cool. Drain freely, which makes them easy to work, but also prone to drought. Organic matter breaks down quickly. Very sandy soils can have unstable structures. Nutrients leach out as no CEC. Sandy soils Good water retention. Can be fertile. Easier to work. Unstable soil structure can lead to capping and water logging. Silt soils Warm slowly and cool slowly. High CEC so fertile. Retain high levels of water which can lead to working and drainage problems. Clay soils