Understanding Soil Types and the Water Cycle for Sustainable Farming

The Ideal Soil for Farming: Loam

The best type of soil for farming is loam. Its balanced composition of sand and clay particles creates both large and small pore spaces. This structure provides an ideal environment for plant growth by:

• Ensuring a steady supply of air and water.
• Retaining moisture while allowing excess water to drain, preventing waterlogging.

Loamy soils are also rich in nutrients due to their clay content and are relatively easy to work with. Their pH level typically falls between 5.5 and 8.0, making them suitable for a wide range of crops.

Sandy Soils: The Hungry Type

In contrast to loam, sandy soils are often described as “hungry” because their large particle size and loose structure lead to:

• Rapid drainage, resulting in nutrient loss.
• Increased need for frequent fertilization to compensate for nutrient leaching.

The Water Cycle and Water Availability

on Earth

Water cycle

 Evaporation takes place due to heat. Water from oceans and seas changes from water droplets to water vapour in the atmosphere. Water is also lost from trees and plants, mainly from their leaves. This is transpiration. Evapo-transpiration covers all water losses from land surfaces.

 Condensation is the process by which the water vapour is turned back into a liquid or a solid. Further cooling leads to precipitation, which is all the moisture that reaches the surface irrespective of type.

 Some water particles are prevented from falling directly on the ground by trees and plants, called interception. Some flows over the ground surface, eventually finding its way into streams and rivers. This is run-off. The remainder steeps underground, downwards by infiltration and sideways by groundwater flow.

The role of water within ecosystems

 An ecosystem comprises all living communities in an area together with its non-living natural environment. It is a system because all elements are interlinked.

 Water stress is when a country worries over present and future water supplies.

How do water-poor countries obtain their water supplies?

 One way is to use desalinization. This changes sea water to fresh water, using large amounts of electricity.

 Another way, water-poor countries pump up water to the surface from natural underground stores called aquifers. Rain water that has accumulated during hundreds of years is used to satisfy people’s present water needs.