Module 6 Healthy Soils
Introduction
Healthy soils are not there simply to support plants and their root systems; soil is a dynamic, living environment and a vital farm resource. Soil health relates to the condition of the soil and its potential to promote plant and animal health, sustain biological productivity and improve the environment
Soil is one of our most precious non-renewable resources and the soil biota represents a large portion of the earth’s biodiversity. Soil organisms regulate a majority of ecosystem processes in soil that are essential for plant growth (nutrient availability and disease incidence), soil health (soil structure and agrochemical degradation) and sustained productivity (development and maintenance of physico-chemical properties of soil). Soil organisms can be grouped according to their size (e.g., microflora, microfauna, mesofauna and macrofauna), phenotypic (morphological) characteristics (e.g., Bacillus spp. vs. Rhizobium spp.), function (e.g., nitrifying micro-organisms) and trophic preference (e.g., bacterial or fungal feeding nematodes).
Australia is a vast country with many diverse soil types, so it is not possible to give an exact set of chemical, physical and biological characteristics for healthy soil. It will vary depending on the inherent qualities of the vast array of soils that exist. Broadly speaking, healthy soils contain nutrients, allow water and air movement, have a diverse population of soil biology, resist erosion, store water, retain nutrients, are not acidifying or salinising, resist diseases and provide a healthy environment in which to grow plants.
This Module will help you answer questions such as:
- How can I improve my soil to maximise pasture growth?
- How can I improve soil organic carbon?
- How can I maintain healthy soil biology?
- Why is groundcover so important to a healthy soil?
- What will a soil test tell me?
More than any other farm resource, soil health is about protecting and building up the capital so that we, as well as future generations, can continue to live on the interest. No amount of technology, genetics or grazing management will protect a business in the longer term if that business is depleting the soil resources.
Nutrients and soil testing for maximising pasture growth are covered in MMFS Module 7 Grow More Pasture.
Develop a simple farm map that includes the main soil types and their potential productivity/management needs.
To protect soil from erosion and provide a stable environment for the soil ‘bugs’.
How to take and interpret soil tests and understand visual indications of soil health.
Including acidity, salinity, sodicity, waterlogging, compaction and non-wetting sands.
