Table of Contents

See also the separate “Earthworms and vermicompost” chapter.

1. Overview

  • Compost works best when applied to the soil before planting.
  • Compost can also be used as mulch – the protective cover placed over the soil to keep moisture in, reduce erosion, provide nutrients and prevent weed growth. Advice on saving water on the farm usually includes (1) Use more mulch and compost combos and (2) keep the crops covered.
  • The steep increases in the cost of inorganic fertilisers and pesticides (many derived from petroleum products) have led many farmers to look at replacing them with organically-derived composts.
  • Continual use of inorganic products have sterilised the soil and killed off the billions of micro-organisms that occur in nature. Reducing (or eliminating) the use of inorganic products and replacing them with organic products brings the micro-organisms back into the soil. These micro-organisms bring depleted soils back to life and provide all the necessary nutrients for healthy plants.
  • When plants have a good, solid food supply at the roots, they are able to combat diseases more effectively than poorly-fed plants. Using composts as fertiliser and plant food ensures a supply of food throughout the growing season and not, as occurs with inorganic fertilisers, a huge boost when applied but a starvation when this is used up or leached out.
Source: Ronald Thomson; Water Wise (Rand Water)

Use more mulch and compost combos (Saving water on the farm)

You can use de-composed organic matter to improve your soil structure and increase its water-retention volume.

“Mulch is a material spread over the top of the soil to keep moisture. Mulch prepared from organic materials such as wood chips or straw will be broken down into compost, further increasing the soil’s water retention ability,” Talisa Water’s experts say. A combination of this mulch and your regular compost can help the ground hold more water in dry spells.

You can also use ‘black plastic mulch’ to cover soil and squash weeds while cutting down water evaporation at the same time. This mulch is basically the same as traditional wood chip mulch, but with added plastic particulate to prevent the sun from drawing more water than you want it to


2. Compost

“Integrated crop-livestock systems improve soil health (if done properly). Leaving animals on field means more nutrients on the land and higher Carbon sequestration” (Hendrik Smith, Grain SA).
  • Compost is formed in nature all the time as plants and animals die and decompose. This natural compost is generally called “humus”. Decomposition involves the breakdown of plant and animal remains into simpler components. As a result nutrients, which are essential for plant growth, are released into the soil. The process of decomposition is essential for the recycling of nutrients.
  • Good compost is an excellent source of beneficial organisms and organic matter. Compost returns nutrients to the soil, increases the soil’s ability to hold water and air, and prevents erosion by binding the soil.
  • Anybody buying bulk compost is advised to seek professional help in choosing a supplier as, in any industry, there are good and bad composts!
Source: Jako Pieterse; Don Blacklaw; Ken Reid; Ronald Thomson


3. Liquid composts (compost tea)

Find the notes at

Compost tea is the cheapest and fastest way to improve soil fertility. Compost tea is made by adding compost to water and multiplying specific micro-organisms. Compost tea restores the biological balance again and improves soil structure and counteracts compaction.