Gabe Brown in Chapter 9 of his book Dirt to Soil credits Jon Stika Author Soil Owners Manual, Jay Fuhrer, Ray Archuleta as being the first to refer to these five principles of soil health.
It is their belief that to ignore these principles will lead to the complete degradation of all nature resources not just soil.
Without healthy soil we can not have healthy crops, or healthy animals or healthy people. We must promote the health and functioning of the ecosystems in which we farm.
Principle One: Limit Disturbance
Limit mechanical, chemical & physical disturbance of the soil. Where in nature do, we find mechanical tillage – nowhere. Widespread tillage destroys soil structure, function and accelerates the breakdown of soil organic matter (carbon). Carbon dioxide is released into the atmosphere and decreases complex mycorrhizal fungi networks resulting in fewer nutrients for plants.
Chronic chemical disturbance is just as devasting, the application of synthetic fertilizer and herbicide can destroy soil structure and ecosystem function.
The prevailing traditional system of agriculture does not provide the means to intensify food and fibre production without degrading the soil resource.
If chemical agriculture is destroying the soil resource how can you justify continuing down this path.
The answer lies in the plant, soil, microbe relationship. If we feed a plant water soluble synthetic fertilizer the plant more or less becomes lazy, it no longer needs to release as much carbon into the soil to attract soil micro-organisms – net result is a decrease of the numbers of beneficial micro-organisms and fungi – less soil life in turn means less aggregation, reduced pore space, and lower water infiltration. Included in this cycle is a significant loss in nitrogen fixing bacteria – so end result is the breakdown of nature eco system.
Principle Two – Maintain Armor on the Soil Surface
Bare soil is a sign of a dysfunctional ecosystem. If bare soil was normal in nature then why do weeds grow whenever soil is disturbed (tilled)? Nature is trying to cover the soil.
Vegetation on soil – protects it, inhibits weed growth, keeps soil temperature down in the heat of the summer, reduces water evaporation rates, provides valuable soil organic matter that is recycled by earth worms that magically appear. This armor is home to a myriad of microorganisms.
Temperature of soil can have a dramatic impact on plant health. Consider the following – when soil temp is 21 degrees Celsius 100% of soil moisture is available for plant growth, at 38 degrees Celsius only 15% is available for growth, the remaining 85% is lost to evaporation and transpiration. At 54 degrees Celsius 100% of moisture is lost to evaporation and transpiration. At 60 degrees Celsius soil bacteria die.
As producers we make our living from growing plants – it’s in our best interest to provide them the best habitat possible especially below the soil surface – keeping the soil well armored should be one of our top priorities.
Principle Three – Build Diversity
Gabe Brown talks about having 140 different species of plants growing in his paddocks – he talks of this replicating nature before humans impacted landscapes. Nature never grows as a monoculture. He believes that farmers need to pay more attention to the four different crop types – cool season grasses, cool season broadleaves, warm season grasses, warm season broadleaves. Each of these influence a field ecosystem in a different way. We should have all four types in our rotations/ pastures.
If a pasture ecosystem in its natural state contains 100 different species of grasses, legumes and forbes how can we possibly expect the eco system to function well if we reduce the plant diversity to one or two species. If you want to improve your soils you must add diversity either by diversifying your crop rotation or using cover crops.
Diversity means more plants are cycling carbon and different plants have different health aspects. One of the many reasons is that a more diverse plant population results in a more diverse range of root exudates to feed microbiology.
Principle Four:- maintain living roots for as long as possible throughout the year
Gabe uses the following analogy – a farmer would never leave their livestock unfed for months at a time why then do farmers not think of feeding their underground livestock through the winter.
Gabe says never ever pass up the opportunity to convert solar energy into biological energy. As soon as a crop is harvested he immediately seeds another crop, think of how this ties to the nutrient cycle, if we are not pumping liquid carbon into the soil we not feeding soil biology, if we are not feeding soil biology we are not cycling nutrients. Once you understand this principle you understand why many producers need to use copious amounts of synthetic fertilizes to grow crops, their soils natural fertility has been starved out.
Another important reason is to advance and improve mycorrhizal fungi in your soils.
Gabe says the only way to increase water holding capacity in your soil is to have as many roots in the soil as possible so that organic matter (carbon) is increased.
Principle Five Integrate animals
Soils were formed by animals like bison roaming landscapes and grazing plants and moving on and often not returning for a significant amount of time. A plant that has been grazed will photosynthesize more and pump more liquid carbon into the soil compared to a plant that has not been grazed. So if animals are not grazing plants you are not cycling carbon dioxide from the atmosphere into the soil.