Biological farming with microbes and trace minerals

The capacity of farmers and graziers to move to biological farming and away from chemical farming is now possible at less cost for fertilisers and increased production.

The recent availability of balanced microbial formulations like the Aloe Vera Microbial Fertilizer has changed approaches to sustainable agriculture and enabled farmers to achieve significant results in soil health, increased plant nutrition and yields within one cropping season of microbial balancing.

Farmers are becoming increasingly aware that the capital value in a soil is primarily the abundance and diversity of microbes, soil carbon, organic compounds and about 70 minerals that plants need to reach their full potential of nutrients and resilience. This natural capital is stressed by chemical farming to the point where the natural feedback loops to sustain a balance of soil moisture, temperature, nitrogen fixation, carbon sequestration and soil life are impaired.

In 2008 I was involved in testing biological formulations in crops and the results from this biological farming trial were dramatically demonstrated on the 'Summer Hill' property of KJ Hughes near Junee (NSW) where he used a liquid microbe formulation with added trace minerals. The farm was able to increase the % soil carbon by 1.4%, Phosphorous availability by 266%, plant nutrients by 100% and grain production by 167%. Importantly the average annual increase in grain production achieved via microbial formulations at this property from 2005 – 2008 was an impressive 80% compared to chemically treated crops on the property. This evidence is contrary to recent CSIRO assertions that additional soil carbon will be a financial liability and tie up macro nutrients at a cost of $200 per hectare per year.

Experience to date clearly shows real and easily identifiable benefits of biological farming. These can be summarised briefly:

1. Larger crops of better quality produce.
2. Shorter growing periods to maturity.
3. Wider growing seasons due to increased soil moisture retention and soil carbon levels.
4. Enhanced natural resistance to many pests and diseases.
5. More nutritious and flavoursome products for the consumer (humans and or livestock) therefore improved marketability.

Experience in biological farming also shows that the use of trace minerals along with microbial balancing is fundamental to food production and security of that production process in adverse climate conditions. It is the combination of a healthy, microbially balanced soil and the adequate supply of trace minerals that increases disease resistance and nutrient density in food.

The extractive farming (taking from the soil and replacing nothing) was of necessity the only cultural practice that could be used in the earliest years of settlement in Australia, in part because the first primary producers were not farmers by tradition and also because no enrichment resources other than manures (animal and green), composts and fallowing were known then. Those excuses for inappropriate farming technologies certainly cannot be accepted in recent years yet the practice (extractive agriculture or mining the soil) continues to be the rule rather than the exception. For example, chemical farming may only add NPK with some Mo and B, however plants grown for food can extract up to 70 minerals and this can leave the soil depleted if that plant matter (food) is exported to supermarkets and not recycled in-situ (as it would be in a natural forest or grassland).

Soil fertility means a balance between organic carbon, the microbial population, inorganic mineral nutrients, inert mineral matter and moisture which together provide the means for growth, metabolic function and reproduction of all the life forms involved. If a suitable balance is maintained, plants have what they need to grow to maturity while the microbes perform their vital work of breaking down crop debris, etc. Vigorous microbial function is essential not only to prevent the loss of organic matter but to produce many complex organic compounds that plants need but cannot make for themselves.

Of the inorganic nutrients, nitrogen, phosphorus and potassium are required in relatively large amounts. Calcium, magnesium, sulphur, chlorine, iron, copper, manganese, zinc, boron, cobalt and molybdenum are also essential in amounts that vary from 10,000 to 30,000 parts per million for calcium to about 10 ppm for cobalt and molybdenum. Another group of elements required in even smaller amounts includes vanadium, chromium, nickel, germanium, selenium, iodine, titanium, tungsten and several others. The amounts required are typically less than 1 ppm to as little as a few ppb. Sodium and silicon are also essential to both plants and microbes but are invariably present well in excess of needs in normal circumstances.

The situation over much of Australia is one of critical shortage of almost everything a good soil should have. This is an ancient land mass and it has been treated harshly by a long succession of glaciers which ploughed much of the topsoil into the ocean. What remains is deficient in essential elements by factors varying from tens to thousands compared with typical good soils from elsewhere. Organic carbon is too low, either because it never was high or because a century or more of inappropriate farming and land management techniques have reduced the % soil carbon to almost vanishing point.

The only barriers to optimum plant growth are the lack of sunshine, water, organic and inorganic nutrients (or too much of the above) or attack by disease or pests. Nutritional deficiency problems develop in a plant when the growth rate determined by photosynthesis cannot be supported by nutrient uptake from the soil. When supply of one or more nutrients falls behind, some part of the plant's metabolism starts to malfunction.

Each nutrient fulfils one or more functions. Chlorophyll, the green pigment in leaves, contains a central atom of magnesium linked to nitrogen atoms. Adenosine triphosphate, the energy currency of all living tissue requires nitrogen and phosphorus. Without an adequate supply of these elements, photosynthesis, the basis of life on earth, cannot take place. Later stages in the conversion of the products of photosynthesis into more complex plant tissue require enzymes cofactors, etc. containing iron, copper, manganese and other minerals. An enzyme mediating transport of plant materials to the growing tips of leaves requires molybdenum, which is also required in a nitrogenise enzyme used by soil bacteria to fix nitrogen into a plant useful form.

Not surprisingly, if all or any of the essential elements are insufficient or unavailable, plant development suffers. Many symptoms of nutrient deficiency can be seen in leaves, stalks, roots and fruit and can be interpreted by people familiar with the signs. Many plants have nutritional needs that vary with the seasons and the secret of growing crops out of season lies in providing the required nutrient balance for that time of year. For instance, lettuce plants in summer require far more boron than a winter crop of the same cultivar to prevent bolting. In fact, almost everything requires extra boron and a few others as well for summer growth.

The conventional wisdom on plant diseases has been to think of disease as a problem caused by attack from specific harmful organisms and that the cure is to kill the organisms with some toxic spray that often kills far more than the targeted pest. In reality nearly all diseases are a symptom and a consequence of nutrient deficiency. The organism that manifests at the height of the trauma is an opportunist that has moved in on a weakened plant and it is not the cause of the disease. Nearly all plants have as part of their genetic heritage a capability for resisting assaults on their integrity by a wide variety of organisms if they are given the wherewithal to make their own ammunition and they can do it more effectively and at lower cost than we can with sprays. A well nourished plant can remain free of disease in the midst of a plaque that destroys nutrient deficient plants.

Rob Gourlay, RFD, B.App.Sc, M.App.Sc.