a) Soil development and analysis
Good soil development requires weathering:
- Physical weathering: the breakdown of rocks and minerals into small particles. This causes an increase in the surface of the material and makes it accessible to chemical weathering. Physical weathering takes place for instance as a result of temperature changes, frost, salt, etc.
- Chemical weathering: this depends on temperature, Ph value, humidity, the nature of the rock and time. Chemical weathering takes place for instance as a result of dissolving, oxidisation, hydrolysis, etc.
- Biological weathering: Decomposition of the rocks and minerals by the excrement and activity of soil organisms, lichen, moss, plant roots and so on.
Since the nutrients mainly attach themselves to the soil particles, with only few being dissolved in the water, the plant roots must be able to grow to reach the nutrients.
The extremely advantageous soil conditions in South and Central America are due above all to the consequences of active volcanoes. Similar conditions apply to parts of South East Asia (above all Java and Bali).
b) Site selection and soil improvement
Ways of improving the site include:
- Activation of the humus
- Cultivation of the soil
Forestry soil cultivation has the following aims:
- Preventing soil compression
- Avoiding soil erosion
- Making seeding possible
- Improving the growth and development conditions for planting
- Mechanisation and rationalisation of the planting and plant care work