About Soil Health

Optimal plant health is governed by the efficiency which plants can convert sunlight into sugars and carbohydrates, and extract nutrients from the soil. These tasks however, are only achieved in the presence of good soil structure and the appropriate balance of both minerals and beneficial microbes.

Plants grown in well balanced soils typically have higher sugar levels and require less fertilizer and chemical inputs, they also tend to be more resilient to pests and disease and have vigorous root systems capable of utilising soil nutrients more efficiently.
 
An active and balanced soil biomass also maintains soil structure which is vital in terms of ensuring adequate Oxygen levels in the root zone, because low Oxygen favours disease organisms, and poor structure reduces water use efficiency - biologically active soils also retain nutrients longer ensuring you get the maximum value from fertilizer additions.
 
How do plants absorb minerals from the soil?

Plants are in fact the linkage between the earths’ valuable mineral resources and human health. By consuming the many food products derived from our soils, we are able to access vital minerals we need to maintain and regulate our own health, directly via fruit, vegetables and grains, and also indirectly via grazing animals and their by-products.

Plants are designed to extract minerals and nutrients from the soil with the expert help of a diverse group of beneficial soil organisms which break down minerals and transform them in a way that enables the plant to take them up, these beneficial soil organisms also perform many other important functions in the soil.
 
A good productive soil contains over 25,000 different species of bacteria, 1,500 species of fungi and hundreds of species of algae, protozoa and nematodes. In terms of numbers, there are many hundreds of millions of these beneficial organisms in every gram of soil, a living biomass which amounts to thousands of kilograms in every hectare of soil.
 
In their natural setting, the plant controls the balance and health of this biomass by directing some of the sugars produced in the leaf during photosynthesis to the roots. The roots use about half of these sugars for growth and the balance is exuded into the soil to maintain the health and balance of the soil eco-system.

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Pushing this intricate and complex eco-system is causing problems.
 
In less than a century, since the wide spread adoption of chemical fertilizers, crop chemicals and high horsepower tillage, we have seen more damage done to our productive soils and at a faster rate than had ever occurred previously.
 
And while many believe that the impacts of chemicals on our productive soils is a relatively recent phenomenon, there are those that could see and predict the present day outcomes decades ago, One of the earliest advocates of the soil and its complex systems was, Sir Albert Howard (1873 – 1947). 

Sir Albert has been referred to as the father on ‘Modern Organic Agriculture’ and as the ‘Father of Composting’ he was one of the first to look upon the soil as an ‘Ecological System’ with soil microbes providing the link between Humus (the soils’ natural Carbon reserves) and the living plant. He saw the essential role of soil biology in decomposing organic matter and constantly replenishing the important soil humus and nutrient levels. Howard is quoted as saying that “the health of the soil, plants, animals and man are as one and indivisible”
 
Following World War I, munitions factories began producing artificial fertilizers and this began the large scale degradation of farming soils. In 1940 Howard said “the restoration and maintenance of soil fertility has become a universal problem, the large scale poisoning of the life of the soil by artificial manures is one of the greatest calamities which has befallen mankind”

He was indeed ahead of his time, even today soil scientists, teachers and managers under estimate the importance of this complex eco-system. When chemical fertilizers are added to the soil they create an environment which soil organisms can’t tolerate, osmotic pressure literally sucks the very life from them. Similarly chemicals such as herbicides, pesticides and fungicides all have a detrimental effect on biology.

The decline in sustainability which we hear much about today throughout agricultural and related media, is the result of the trends that Sir Albert Howard could see all those years ago.

Today many are trying to link sustainability and soil decline to climate change and carbon emmissions, however it's actually the cummulative damage being caused to soil biology by modern soil management techniques which is having the most significant impact on the soil. It affects the very structure of the soil, its ability to recieve and store water, to break down and stabilise organic carbon, to cycle and retain nutrients and to provide some level of competition against soil borne diseases.

Of course it's impossible to go backwards, and we wouldn't propose that in any circumstance, but there is a case to be put for using chemicals and fertilizers more wisely in order to reduce their impact on the soil.

- Did you know that the number and volume of chemicals applied to soils and plants has increased each and every year since we started using them 60 years ago.

- Did you also realise pest and disease pressures have also increased each and every year since we began using chemicals and chemical fertilizers.

- It's also sobering to reflect on the fact that not a single pest or disease has ever been eliminated as a result of the billions of litres of chemicals introduced into the environment and which are reducing the soils’ productive capacity.

In contrast, the plants we rely on to grow quality turf surfaces and landscapes as well as fruit and vegetable crops or pastures, have all evolved in the presence of, and rely on a strong and symbiotic relationship with beneficial soil organisms which play a significant role in regulating the health of the entire plant/soil eco-system.       

Is it just Agriculture that is being affected?
 
Of course not, there are many other land based enterprises such as the management of Golf and Bowling greens, Sportsfields, Garden beds, Floriculture, and even our own home gardens are all affected to some degree because they all rely on the soil to produce a product. Of course most of these are not directly related to human health, but the same chemical and soil management interface has created the same symptoms of soil decline, imbalance and a need for an increasing level of chemical inputs.

Many of these situations are also in close contact with human activity, consequently the increasing use of chemicals is becoming a growing concern, both from an occupation health perspective but also from an environmental management one.

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How do you know if your soil has been affected?

Many of our intensively managed soils have become biologically weak and resident populations of beneficial soil organisms have declined or become unbalanced, we see this through the diagnostic testing we have done over a number of years now.

In the normal course of our business we get to see many soils and crops, more often than not we are asked to look at those which are not doing so well. It’s very common to be told how a paddock/soil was good when it was first brought into production, and in the next breath we are told how quickly it has declined and is no longer producing as well, a process which can sometimes take only a few years.

As the soil biomass declines under the pressure from modern techniques and chemical inputs, the soil structure collapses, pore spaces in the soil reduce and the soil gradually becomes more compacted. Once the soil structure begins to close, the flow of Oxygen and moisture to the roots is reduced, creating anaerobic conditions that favour disease-causing organisms, resulting increase in disease and insect pressure, as well as lowering pH levels.

One of the first signs that growers can relate to, is the change in soil structure, and as the soil becomes tighter and more compact, it becomes harder to work, it becomes difficult to water, runoff increases and it needs an increasing level of inputs just to grow a reasonable crop.

In the Sportsturf industry soils tend to be biologically weaker to begin with so the damage from chemical inputs will often occur much more quickly. In terms of symptoms it is more often expressed in terms of increased disease and insect pressure.

In an unbalanced soil environment individual diseases and/or pests (particularly nematodes) can quickly gain a position of dominance and can cause long and persistant damage until the balance is improved. Once these organisms become dominant they can resist continual applications of chemicals - it's all about balance nature is built on it.

For anyone managing the soil, being faced with plants that are stressed or faced with increasing disease and insect pressure, it is natural to turn to chemical sprays for control (you have to), we just have to remember that these products also have a huge detrimental effect on the soil biomass. The solution to these problems is to periodically put something back for the soil, to rebuild soil biomass and improve biological balance, because ultimmately it will reduce the need for chemical intervention and take some pressure off yourself.

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