Soil Biology

Soil is a complex and dynamic habitat for soil organisms. Beneficial biological activity is heavily dependent on organic matter which provides a food supply for many organisms and this is influenced by land use, soil chemical composition and climate. The presence and ratios of mesofauna (animals 0.1 mm to 2 mm) can be good indicators of soil health. Mites and springtails are indicators of good biological activity. Mycorrhizal fungi help plants access water and nutrients by acting and an extension of their root systems. Soil aggregates, the presence of tiny white threads (hyphae), moisture and earthy smell can all be good indicators of mycorrhizal fungi. A healthy soil microbiome can improve nutrient uptake in plants, reduce susceptibility to pests and pathogens and improve soil fertility and structure.

What Inhibits Soil Biological Function?

1. Soil acidity;
2. Poor soil organic matter management;
3. Low groundcover;
4. Tillage practices; and
5. Cropping sequences.

Solutions

• Minimise erosion as soil organisms live mostly in the surface layers;
• Maintain or increase the organic matter content of soil;
• Use diverse rotations as they increase organic matter composition;
• Don’t burn stubble; and
• Choose crops and management practices that minimise plant pathogens.

Further Reading

Australian Institute of Ecological Agriculture. 2018. ‘Farmer endorsement program (FEP).’ http://ecoag.org.au/get-involved/farmer-endorsement-scheme/

Clapperton, J. 2012. ‘Pesticide effects on soil biology.’ https://gardendrum.com/wp-content/uploads/2012/11/PesticideEffectsOnSoilBiology.pdf

Department of Primary Industries and Regional Development (DPIRD). 2018. ‘Utilising soil biological processes to better manage water repellent soils.’ https://www.agric.wa.gov.au/water-repellence/utilising-soil-biological-processes-better-manage-water-repellent-soils

Integrity Soils. 2016. ‘Regenerative Ag.’ https://www.integritysoils.co.nz/regenerative-ag/

Regenerative Australian Farmers: Promoting Healthy Soils. 2017. https://regenfarmers.com.au/

Soils For Life. 2017. ‘Regenerating our landscape.’ http://www.soilsforlife.org.au/_blog/SoilsforLife-Blog/post/The_Wonderful_World_of_Soil_Biology