By: Molly Shaw and Charles Merfield Published: The BHU Future Farming Centre, The FCC Bulletin – 2013 V1 July
Soils are quite literally the foundation of the farm so ensuring they are well managed is a fundamental task for farmers and growers. For decades now we have been good at measuring and managing the chemical properties of the soil-pH, NPK levels etc.,-all the things that show up on a standard nutrient test, but soil biology has been largely ignored.
However, more recently, there has been increased interest in managing soil organisms and soil “health” in general. With all that interest also come some questionable theories and sales claims about products and methodologies that boost soil microbial activity, soil ‘health’ and/or plant productivity. To sort through the hard science and separate it from the myths and marketing hype, Natural England, part of the UK Government, commissioned a broad review of over 200 scientific studies related to the functioning of soil organisms in agricultural systems. Along with the literature review, they consulted with producers to work out which techniques were the most practical to implement in real-world farming . The report can be downloaded from http://publications.naturalengland.org.uk/publication/2748107
Boiled down to the nitty gritty, here’s what they found:
Soil organisms give us these benefits:
- Nutrient cycling and holding capacity (creating a fertile soil);
- Good soil structure, with benefits such as reduce need for tillage, improved water infiltration and retention (well-aggregated, spongy, drought-resistant soil);
- Promotion of crop growth/ health (e.g. rhizobacteria fixing N with legumes, mycorrhizal fungi).
You improve the work of soil organisms by:
- Feeding the soil a diverse diet. This entails increasing the variety and overall amount of organic matter adding to the soil (e.g., having a range of crop residue types and using green manures); and / or
- Reducing tillage, both the total amount and also intensity (e.g., surface working vs. ploughing); and / or
- Diversifying cropping systems (having a wider range of crops and/or pasture).