The Importance of humates in soil structure


Humates are a pure form of organic matter, resulting from an accumulation of decayed forest and carbon rich plant residues that have been compressed and preserved over the ages.

High in carbon, natural minerals and trace elements, Humates contain two powerful bioactive acids, humic and fulvic acid. The material is known for the beneficial role it plays in stimulating microbiological activity and increased
fungi levels in soil.

Humic acid is a group of molecules that bind to and help plant roots receive water and nutrients. They are therefore extremely important as a medium for transporting nutrients from the soil to the plant. Their ability to hold on to ionized nutrients prevent them from
being leached.

Positive ions are more easily absorbed by a plant’s root due to the root having a negative charge. In other words, the positive (cation) is attracted to the negative (the living root). Humic acids hold cations (positive ions) in a way that can be more easily absorbed by a plant’s root, improving micronutrient
transfer to the plant’s circulation system. This works through humic acids (ulmic, humic and fulvic) picking up positive ions and then being attracted to the root depletion zone and to the hyphae micro- tubes of mycorrhizae.

Four years of independent field trials have resulted in a paper being published in Nature Science Journal confirming the addition of humate to urea increases pasture growth. The ful paper is available under “Articles” at

A field trial is just underway in the Bay of Plenty that will assess the effects of humates in reducing nitrate leachingng in kiwifruit orchards. A further kiwifruit field trial is investigating the effects of humates on heavy metals and this is indicating a positive result.

International lab analysis of Southern Humates product indicates a high level of carbon, 43%; humic acid, 48%; and Cation Exchange Capacity (CEC) of 78 meq/100g. It is generally considered that the high levels relate to the geographic location of the Southern Humates site in the deep south at Wyndham.

Southern Humates supplies a range of products in both solid and liquid form to meet spreading requirements across both agriculture and horticulture sectors. The range is certified organic
for input.

For further information please contact your Farmlands Technical Advisor, or local Farmlands branch.

Supplied by Janet Brooker Southern Humates