The single thing that troubles me the most on our farm at the moment is exposed soil surfaces (lack of soil armour). This is a widespread issue that affects thousands of hectares around us. Being mediterranean with wet winters and very hot dry summers, an annual rainfall averaging 250mm/annum; all these factors add up and greatly increase soil temperatures.
- At 21°C: The soil microbiome is functioning at an optimal level ( microbe activity between 10-28°C). All the moisture within the soil is effectively used for photosynthesis and therefore plant growth continues. For this reason, keeping the soil at this temperature and moisture level with permanent ground cover should be the main goal.
- At 37°C: Although temperature increases some microbial activity, we are now faced with an 85% loss in moisture through evaporation and transpiration thus limiting the nutrient uptake, much of which occurs through oxygen diffusion or osmosis.
- At 54°C: all the moisture within the exposed soil is lost through evaporation and transpiration leaving the soil microbiome largely ineffective
- At 60°C: Soil microorganisms die due to a lack of nutrient uptake and enzyme denaturation; essentially they are starved.
Mycorrhizal fungi in the soil is important for improving aggregate stability, build soil carbon, improve efficiency of water use and increases nutrient cycling of Nitrogen (N), Potassium (K), Sulfur (S). The only way to improve it is to have permanent soil cover- we refer to it as soil armour.
Right from the very start we have used an organic approach: eliminated the use of chemicals and fertiliser application, remained no-till and started to focus on perennial ground cover (our soil armour). The next blog will lay out the next logical stage of the process.