1. Introduction to Soils Mike Tanti

2. What soil is made from? Soils are complex substances made from a number of materials and organisms. These include: Soils are complex substances made from a number of materials and organisms. These include: tiny particles of rock of different types tiny particles of rock of different types decaying plant material and animal matter decaying plant material and animal matter animal life animal life micro-organisms micro-organisms water water air. air. If these things exist together correctly they form healthy soil that is essential to good plant growth and development. Over time, generations of plants have adapted to grow in different types of soil. If these things exist together correctly they form healthy soil that is essential to good plant growth and development. Over time, generations of plants have adapted to grow in different types of soil.

3. Why soil is important Ecology Ecology Soil is a vital component to the ecology of the planet. Soil is a vital component to the ecology of the planet. Soil can be seriously affected by changes in climate, incorrect cultivation and management, pollution and the removal of the vegetation it supports. Soil can be seriously affected by changes in climate, incorrect cultivation and management, pollution and the removal of the vegetation it supports.removal of the vegetation removal of the vegetation Once a soil has been damaged or changed, it is difficult to return it to its original condition. Once a soil has been damaged or changed, it is difficult to return it to its original condition.

5. Why soil is important Economy Economy A fertile soil will produce healthy, plentiful crops. A fertile soil will produce healthy, plentiful crops. These crops include trees for timber, decorative plants, cut flowers and food crops. These crops include trees for timber, decorative plants, cut flowers and food crops. In turn, the value of the crops will contribute to the economy of an area or country. In turn, the value of the crops will contribute to the economy of an area or country.

6. Why soil is important Environment Environment Soil is essential to the majority of plants. Soil also provides a home for animals, insects and other organisms. Soil is essential to the majority of plants. Soil also provides a home for animals, insects and other organisms.

7. How soils help plants grow Plants depend on soils for many things such as nutrients, stability, water, warmth and air. Plants depend on soils for many things such as nutrients, stability, water, warmth and air. If stability, nutrients, warmth, water and air are not present in soil in sufficient amounts, a plant will not grow and develop. If stability, nutrients, warmth, water and air are not present in soil in sufficient amounts, a plant will not grow and develop.

8. Nutrients Soil contains all the essential nutrients plants need for growth and development. Soil contains all the essential nutrients plants need for growth and development. These nutrients come from the rock particles and organic matter. These nutrients come from the rock particles and organic matter. There are 3 major plant nutrients and 10 minor plant nutrients required by all plants. Specific plants may also need some other nutrients. There are 3 major plant nutrients and 10 minor plant nutrients required by all plants. Specific plants may also need some other nutrients. Carbon, hydrogen and oxygen are also classed as nutrients which are mainly extracted from the atmosphere. Carbon, hydrogen and oxygen are also classed as nutrients which are mainly extracted from the atmosphere. Nutrients must be dissolved in water before they can be taken up by plant roots. Nutrients must be dissolved in water before they can be taken up by plant roots.

9. Stability Plant roots spread into the soil searching for water. Plant roots spread into the soil searching for water. The roots firmly anchor the plant, so it survives the effects of weather and damage from animals. The roots firmly anchor the plant, so it survives the effects of weather and damage from animals. Roots bind soil particles together making the soil more stable and creating channels for air and water. Roots bind soil particles together making the soil more stable and creating channels for air and water.

10. Water Plant roots take up water from the soil. Plant roots take up water from the soil. Water is needed by plants for rigidity, as a transport system and for processes such as photosynthesis. Water is needed by plants for rigidity, as a transport system and for processes such as photosynthesis. Soil water is stored in spaces between the soil particles called pores. Soil water is stored in spaces between the soil particles called pores.

11. Warmth Soil gets most of its warmth from the sun (solar energy). Soil gets most of its warmth from the sun (solar energy). Plant growth and development occurs as a result of chemical reactions and these happen quicker in warm conditions. Plant growth and development occurs as a result of chemical reactions and these happen quicker in warm conditions. Some soils warm up and cool down quicker than others depending on their other properties. For example, a heavy water-logged soil that contains little organic matter will cool down and warm up slowly. Some soils warm up and cool down quicker than others depending on their other properties. For example, a heavy water-logged soil that contains little organic matter will cool down and warm up slowly.

12. Air Air is found in the soil pores that are not filled with water. Air is found in the soil pores that are not filled with water. Air in the soil helps plants take up nutrients, provides oxygen for underground plant cells, Air in the soil helps plants take up nutrients, provides oxygen for underground plant cells, gives soil a loose structure to allow roots to spread gives soil a loose structure to allow roots to spread and provides oxygen for the micro-organisms living in the soil. and provides oxygen for the micro-organisms living in the soil. Ideal soil will have both air and water in the pores. Ideal soil will have both air and water in the pores.