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Modern Farming with Biologically Active Soils

Posted by Blake Lissington on 06 09 2015.

(This is a guest post by Pete Kerdemelidis from AgriChem – www.agrichemnz.com)


In today’s competitive farming environment we must use every tool in the shed to get the best result we can.  We are not only farming for today but we are farming for tomorrow and the future.  The key is maximising our production in a sustainable farm management plan so we can mitigate all risk for our chosen production.

The question asked is “how can we do this?”

The answer is easily.  By selecting the right crop or pasture for the site, looking at the plants nutritional requirements, working out what is already in the soil, what can be made more available by activating soil biology, what risks we can reduce by having a functioning soil biomass, what is likely to happen in the upcoming season, and importantly (although often forgotten) animal health and nutrition requirements.

In the simplest terms inorganic fertilisers like Urea are broken down by environmental weathering and further digestion by bacteria.  Fungi through a symbiotic relationship with bacteria then feed the plant these nutrients.  The plant in turn provides sugars (simple and complex carbohydrates) via the fungi to the colonies of bacteria and the cycle continues.

The process sounds simple and is.  The problem is what happens when soils are not functioning well, i.e. are high in bacteria or low in fungi?  The Bacteria:Fungi ratio should be 1:1 for grassland, more bacteria for brassicas, more fungi for woody plants like tress/ shrubs.  Ever wondered why a newly worked paddock that’s put into brassicas works well for the first season – bacterial dominance.  Too much or too little can cause problems so it’s best to check through a reputable lab like The Soil Foodweb Institute.

Soils that are hard and compact, prone to waterlogging, worked regularly will be low in fungi and high in bacteria as fungi generally perish first while bacteria are more resilient.  If they receive high levels of inorganic fertiliser they will also be the same.  The solution to this is to feed the soil with a fungi feeder and a source of organic protein (nitrogen).  The best form of this is fish based.

Increasing fungi levels allows expansion between the soil platelets in compact soils by increasing colonies.  This gives the effect of a more “spongier” soil.  It also allows soils to form colloids and provides structure.  With the increase in fungi larger soil biology come next allowing pathways in the soil for air and water to be held and to be drained.  With more soil biology the effective topsoil increases in depth allowing grasses etc to penetrate deeper into the soil increasing their ‘feeding’ ability and water access.  This cycle continues and expands what we actually farm.

Consider the soils in a native bush setting – their ability to hold and dissipate water, the depth of effective soil, the smell, its ability to effectively cycle nutrients and hold onto them, the nutrient density of what is grown and compare this to a typical farm paddock.  The differences would be obvious to most people.  Imagine a paddock with this level of biological diversity – the nutrient dense soil with a high production capability.

How can we do this for most farms?

Easily, simply, biologically, sustainably and cost effectively.  By feeding the soils miners (bacteria), providing the infrastructure and highways (fungi), delivering products to market (the roots and plant), paying the workers (carbohydrates and simple sugars from the plant through the fungi to the bacterial colonies).  The perfect commercial operation.

In essence, we apply organic proteins (nitrogen) at key timings:

  •         Autumn:  To keep the soil biology particularly fungi living and expanding through winter.  Feed the workers through winter and keep their populations high.  This should give you an extra few week’s growth before temperatures drop and growth reduces.  Organic nitrogen is more effective here, but what we are trying to do is maintain populations.
  •         Early Spring:  To kick start the biology early and start the cycle.  By doing this it will increase the effectiveness of further fertiliser applications.  Starting to increase the nutrient density of grown matter from what is in the soil or has been applied.
  •         Peak of Summer:  December/ January is generally hot and dry and inorganic fertilisers have a slower response.  By feeding the bacteria (miners) and the fungi (pathways to the root system) the biology will operate at a maximum allowing plants to continually grow in an otherwise stressful/ high demand situation.

Inorganic fertilisers can be applied at reduced rates that still allow farms to crop to their desired levels.  By following this approach overall fertiliser use can be slowly reduced as the soils health and biology are increased.  With increased biology, greater water holding and nutrient cycling are made available to feed the larger root mass exploring deeper into the topsoil that is also expanding.  With more nutrient being absorbed into the plant its nutrient density increases which can assist in maintaining healthier animals that graze the crop.  More diverse nutrients into crops can reduce animal dietary issues and potential health problems.

So what do we recommend?

Grow the best you can grow in a sustainable biologically diverse system that will cost you less over time as you feed and nourish your soil system.  Always soil test and choose products that will enhance your soil and biosystem rather than products that will get you the quick fix at a long term cost.

***This blog post was written by Pete Kerdemelidis from AgriChem – www.agrichemnz.com

Blake is the head of our sales and marketing team.

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