There is some confusion in New Zealand farming circles about the need for humates and what they can do to improve soil health. Much of this confusion stems from a misunderstanding of the difference between soil organic matter, humus and humate. Although they originate from the same substance, their impact on your soil can be very different.

To help you to understand the role humates can play in your soil health regime we have answered the four most common questions we receive...

1.   What is humate?

Humates is used as a general term to describe the three different types of raw mined soft coals (also known as lignites). Humates are extremely complex substances that are the result of the breakdown of organic matter in peat bogs millions of years ago. Humic compounds (humic and fulvic acids) are the biologically active fraction of humates which have been extracted from the raw humate.

2.   Why use humates at all?

Many cynics argue that processed humates are far too expensive, while others argue that adding humates at all is pointless because you are simply adding more carbon to the soil when there is already plenty there. The reality is that humates are important, because they represent a huge source of valuable minerals, enzymes, plant stimulants and energy, which can all help to boost biological activity and the overall health of your soil.

3.   Are all humates created equal?

As you can see the humic acid on the left is far more soluble than the raw humate on the right which means it will coat fertiliser particles better and be more effective at speeding microbial digestion of fertilisers.

There is a huge difference in performance between processed soluble humates, in the form of concentrated humic acids, and raw humates.

Concentrated humic acids are created by extracting and concentrating the minerals, enzymes, plant stimulates, humic acid, fulvic acid and energy from raw humates. Because they have been extracted and concentrated they become immediately active in water and in soils. By comparison, raw humate powders can take months or even years to break down and become plant available.

Humic acids work by promoting microbial digestion of your fertiliser, which
helps to hold it in the root zone, increasing the amount available for absorption
by your pasture. While raw humate is more usable by microbes and plants
than undigested soil carbon, humic acids are in another league entirely.

4.   How do humic acid granules work?

Abron's soluble humic acid granules are a concentrated source of the bioactive components of high quality humate, extracted into a 90% soluble granule for immediate microbe and plant stimulation. When moistened, the granules quickly dissove and coat the surrounding fertiliser particles with complex humic compounds. Fertiliser coated in these compounds is more quickly digested by soil microbes, which ensures it is immmobilised in the crop or pasture root zone so that leaching is minimised. Humic acid chelation of fertiliser also markedly increases plant uptake thereby providing more nutrients to the plant and a better yield.

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Get more bang for your buck

The perception of humic acid granules is that they are far too expensive, however you need to apply far less per hectare and when you do the maths and consider the better performance of humic acids, the advantages are obvious. A 200ha farm could require only $8,000 worth of humic acid granules (200ha x 8kg/ha x $5/kg) compared to $17,000 worth of raw humate (200ha x 100kg/ha x $0.85/kg). Yes, humic acid granules are more expensive per unit, but overall, they can work out much cheaper.

The key thing to stress is that humic acid granules are a bio-activation tool NOT a carbon source. New Zealand soils have plenty of carbon but it’s inactive and in a form that keeps minerals locked up. Humic acids promote the digestion and decomposition of this soil carbon into humus, the biologically active storehouse for water, microbes and plant stimulants.

The benefits of humic acids:

• Improves soil structure and porosity
• Improves the release of plant nutrients through decomposition by organisms
• Has a growth promoting effect
• Significantly increases the uptake of minerals including phosphorous, sulphur and nitrogen as well as micronutrients
• Removes toxins from soils and animals
• Improves yields
• Stimulates soil microbial activity