Soil Science Fundamentals

Study Notes

Soil Texture

Refers to the proportion of sand, silt, and clay particles in the soil
Classified into three main categories:
1. Sandy soil: high sand content (>50%), coarse, well-draining, and often lacks nutrients
2. Silty soil: high silt content (20-50%), moderate drainage, and holds more nutrients than sandy soil
3. Clay soil: high clay content (>50%), fine, poor drainage, and often retains more nutrients
Texture affects soil's water-holding capacity, aeration, and nutrient availability

Soil Structure

Refers to the arrangement of soil particles into aggregates or clusters
Classified into four main categories:
1. Granular structure: well-aggregated, porous, and allows for good water infiltration
2. Blocky structure: moderately aggregated, moderate porosity, and moderate water infiltration
3. Prismatic structure: poorly aggregated, low porosity, and poor water infiltration
4. Platy structure: very poorly aggregated, very low porosity, and very poor water infiltration
Structure affects soil's water-holding capacity, aeration, and root growth

Subsoil

The layer of soil below the topsoil, typically 10-20 cm deep
Often has a different texture and structure than the topsoil
May have a higher concentration of minerals and nutrients
Plays a crucial role in water filtration and storage

Topsoil

The uppermost layer of soil, typically 5-10 cm deep
Rich in organic matter, nutrients, and microorganisms
Supports plant growth and is essential for agricultural productivity
Often has a higher pH and water-holding capacity than the subsoil

Soil pH

A measure of the soil's acidity or alkalinity
Ranges from 0 (very acidic) to 14 (very alkaline), with 7 being neutral
Most plants grow best in a slightly acidic to neutral soil pH (6.0-7.0)
pH affects nutrient availability, microbial activity, and plant growth

Bedrock

The solid, unbroken rock that underlies the soil
Can be composed of various types of rock, such as granite, basalt, or limestone
Affects soil formation, drainage, and fertility
Can influence soil pH, nutrient availability, and plant growth

Description

Explore the basics of soil science, including soil texture, structure, and composition. Learn about the different types of soil, their properties, and how they affect plant growth and ecosystem functioning.