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The Six Challenges of Dependence on Soluble Fertilisers to provide Plant Nutrition and why Humus Provides the Solution

Friday, September 14, 2012

The Six Challenges of Dependence on Soluble Fertilisers to provide Plant Nutrition and why Humus Provides the Solution

Unfortunately almost all growers and Agricultural advisors around the world have a flawed view of plant feeding.   YLAD Living Soils have researched over many years how plants take up nutrients and water and understand how to grow a healthier plant more resistant to fungal attack, frosting, droughts, disease and pests.

Worldwide research reveals that:

  • When all plant nutrients are soluble and available within soil water, which is almost every ‘bought’ fertiliser, the plant takes in nutrients through its water roots.  This happens 24 hours a day whether the sun is shining or not and whether the plant is making new substances or not.                                                                                                                        The natural reaction to this ‘free’ nutrient by the plant is to try and dilute it down to a normal level by taking in yet more water… hang on now, it gets even more nutrients so  it takes in more water,  so on and so on.  The cell structure becomes bigger and bigger like a balloon until it can expand no more.                                                                                                                     The roots of these particular plants will be very bare and white with very few microbes feeding off the plant exudates.  I call these types of roots ‘naked’.  When a plant has ‘naked’ roots it has no means of ‘feeding’ itself and must rely on you to provide ‘food’.  This is a very costly exercise as the cost of fossil fuels increase so does the cost of man-made fertilisers.
  • What we have now is one big watery plant lacking essential nutrients to build plant sugars.   This plant actually does not transpire as freely as our naturally fed plants as it wants to hang onto its water to keep diluting the nutrient salts.
  • New research from Illinois University has been able to measure the amount of a particular nutrient taken up by the plant in the soil water and there is very little surprise to know that nitrogen is taken up 2.7 times more than calcium or phosphorus. It is this oversupply of nitrogen that adds more water to this already ‘big watery plant’.
  • Products such as bio-solids and raw manures also act as a soluble nitrogen source producing plants that are watery with incomplete protein chains more susceptible to frosting. When this occurs we have lower quality protein, less and less developed flavours and a big watery bitter plant being force fed! 
  • However the worst is yet to come, this big watery plant is attractive to fungal growth.  In nature, insects and pests are there to ‘remove’ the unhealthy problems from the system, they are the clean-up crew, however in this system they are not there to ‘mop’ up the pests or disease.
  • Soluble fertiliser application begins the destruction of soil biodiversity by diminishing the role of nitrogen-fixing bacteria and amplifying the role of everything that feeds on nitrogen. These feeders then speed up the decomposition of organic matter and humus. As organic matter decreases, the physical structure of soil changes. With less pore space and less of their sponge-like qualities, soils are less efficient at storing water and air. Water leaches through soils, draining away nutrients that no longer have an effective substrate on which to cling. With less available oxygen the growth of soil microbiology slows, and the intricate ecosystem of biological exchanges breaks down.
  • With the nutrient level of our plants and food dropping it is now time to address how we can reduce or ‘hang on to’ soil nutrients and allow the plant to take up its ‘food’  in the balanced ratios, producing more nutrient dense food and healthier crops.

Firstly, beneficial bacteria help to retain and provide water through multiple mechanisms.  The cellular content of a prokaryotic bacterial cells is anywhere from 60-80% water.  That means the majority of what is being added to soil when inoculating with beneficial bacteria is water.  Also, the bacterial biomass provides a giant buffering and retention system for the water that becomes available when needed.  When water is available, the bacteria divide and incorporate it into their cell bodies.  When conditions become dry, the bacteria can re-release this water this water to make it available to the plant.

Secondly, bacteria store and retain water in biofilms.  Beneficial biofilms are polysaccharides (sugar) secreted by beneficial bacteria that they use to retain nutrients and water.  Polysaccharides can bind many times their weight in water.  This is water retained in the soil that would otherwise wash through or evaporate.  The water is concentrated in the rhizosphere around the root zones, where the microbes are concentrated.  The plants do not create this emergency water reserve, they provide the roots and the microorganisms store the water.

Thirdly, beneficial microbes produce water as a by-product of their normal functions for such metabolic activities such as bacterial photosynthesis and products of cycling nitrogen.

When you breathe onto a mirror you will see the water that your body expels as a by-product of its metabolism.  Having billions of bacteria constantly ‘breathing’ in the soil is analogous to this process, producing water in the soil.

Fourthly, the decomposition of organic matter releases water, and this process is driven by microbes in the soil

These findings and conclusions of the researchers can be tested by comparing roots in soils inoculated with beneficial bacteria to roots in a sterile soil.

What is the Solution?

Since populations of free-living soil microorganisms are strongly carbon limited Wardle (1992) rhizosphere carbon input from plant roots via rhizodeposition is the driving force for the well-documented ‘rhizosphere effect’, which stimulates microbial growth and activity in close proximity to plant roots (Hiltner 1904, Semenov et al 1999). 

A plant fed with colloidal Humus, which is a very special substance that holds the normally soluble plant nutrients from leaching or locking up, the correct ratio of minerals are taken up by the plant.  We need an active rhizosphere (area surrounding the roots) with high numbers of beneficial microorganisms obtaining nutrients held in the humus via the feeder roots. 

Given the chance in a natural situation a plant will only feed when the sun is telling it to do so and take up just enough ‘food’ to grow the plant. All nutrients are converted into plant material and high quality proteins, flavours, sugars and starches. 

For over ten years YLAD Living Soils have proven the above research to be true and can assist you with biological and humus programs to grow a healthier plant delivering higher quality.

Root exudates can also have protective functions against pathogens from where it is released into the rhizosphere in significant amounts. 

YLAD Humus Compost assists plant growth and microbial growth by the production of growth stimulating compounds encouraging root growth, making it easy for roots to travel through the soil and take up necessary nutrients, in the right balance at the right time. Roots are the digestive system of the tree and plant and a healthy root system determines the microbiology that lives around the roots, beneficial microbes will out-compete pathogens, meaning less disease issues.

YLAD Living Soils over their last 10 years in business have been promoting the essential balance of physical, chemical and microbiology with proven results, both independent and farmer trials. Soil microbiology ten years ago was rarely spoken about and no value placed on the huge role it plays in creating soil structure, nutrient cycling, plant health and disease suppression.

When a soil lacks microbiology and the ability to recycle and supply these nutrients to the plant, the plant then becomes very dependent on the farmer ‘feeding’ water-soluble N & P, which can lock-up, leach or evaporate.   When this oversupply of N & P occurs the microbiology cannot perform their role of fixing nitrogen (for free), solubilising phosphorus and staving off disease organisms.

Nitrogen seems to be a nutrient that farmers rely on most, believing that only when they supply large amounts of soluble N will they obtain high yields and quality.  Over the past 10 years this has proven incorrect showing that there are alternatives to achieving a similar or better results.  These alternatives not only supply short term gains but contribute to long term benefits such as improved soil structure, organic carbon increases and meeting environmental parameters.


Douglas, W. & Speed, S.R.- Florida - Soil Microorganisms and H2O – Microbes Create Emergency Water Reserve.  What takes place in the Root Zone of a Plant?

Petra Marshner – Nutrient Cycling in Terrestrial Eco-Systems

Rod Turner – The World’s Best Compost and Why