black cow on green grass field during daytime

Humates And Organic Dairying

What are humates?

Humates, or humic substances, are a critical organic constituent of healthy soil. They are the product of decomposed plant matter. Humates contain the biochemically active substances humic acid and fulvic acid, with quality products providing a range of benefits to soil and dairy cattle.

three black and white cows walking along a grass field

Humic acid is the larger molecule and is well known as a soil conditioner. Here are a few of the ways humic acid improves soil health:

  • It helps stabilise soil and significantly improves water retention and drainage; 
  • It has a high cation exchange capacity, meaning it binds well to nutrients such as calcium, magnesium, and zinc through chelation. This chelating property means nutrients are held in the soil and made more available to crops; 
  • Binds and reduces the precipitation and leaching of Nitrogen and Phosphorous
  • There is also evidence that humic acid changes the metabolism of microorganisms in the soil, resulting in a higher concentration of microbial life
  • Attaching to heavy metals and detoxifying the soil.

Fulvic acid is a smaller molecule and equally as important. Some of its benefits are:

  • Ability to bind to nutrients and transport them across cell membranes;
  • Stimulates root development;
  • Improves photosynthesis
  • Prevents and makes plants resilient to stress.

Maximising Nitrogen usage with humates

Nitrogen is one of the most important nutrients plant life requires. However, a particular issue plaguing New Zealand dairy farming, and agriculture generally, is nitrogen leaching in the soil. If crops can’t take up the available nitrogen, it sinks into the groundwater and ends up in freshwater systems. The problem has even inspired the recent introduction of freshwater regulations to cap the use of nitrogen on farmland. 

Currently, the most cost effective source of Nitrogen is urea. While it’s high in Nitrogen, it is also easy to handle and store. Its major downside is its high rate of volatilisation. As much as 30% of applied nitrogen can be lost through ammonia volatilisation under certain conditions, which drives up costs and contributes to environmental concerns. 

A study [1] conducted at Agland Farm, Mataura, looking at the effectiveness of urea combined with humate over four years showed some impressive results. Pasture yield increased by almost 10% more than urea only application, while significantly increasing microbial diversity. 

Interestingly, the study found the urea/humate solution maintained nitrogen levels in the soil through winter, when risks from nitrogen leaching are highest due to high rainfall and soil moisture. 

Some New Zealand dairy farms have reported reducing their dependence on urea through the inclusion of humates. This shows that humates can stabilise Nitrogen and reduce volatilisation, which will lead to greater nitrogen efficiency and less leaching. 

Improving dairy cattle health

Humates have a similar effect on a dairy cow’s physiology as they do on the soil. Just as humates promote the proliferation of microbes in soil, it also increases beneficial microbes in the gut. This probiotic effect improves digestion of dry matter. This leads to lower feed intake as available feed is ingested more effectively. Humates have also been shown to increase milk yield and lengthen lactation periods, giving farmers a longer milking period. [2]

The detoxifying effects of humic acid are also present here. Various disease spreading bacteria release toxins that humic acid can bind to and get rid of. Studies have also noted a dramatic reduction in the incidence of mastitis in cows being given humates. [2]

The animal benefits of humates also extend to a reduction in nitrogen waste. The presence of volatile ammonia in the urine of test herds was reduced by 64%. Given that animal waste is a significant contributor to nitrogen leaching issues, this is hugely important.

The overall effect of Humate benefits were both consistent and persistent.

If you have questions, please feel free to reach out. I’d love to learn more about your growing operation and how Roots, Shoots & Fruits products can help you to grow better. 

[1] Bioactive carbon improves nitrogen fertiliser efficiency and ecological sustainability,

[2] Trials with fulvic/humic in animals,

1 thought on “Humates And Organic Dairying”

  1. For use with cattle. How much humate was given per pound of body weight or how was it distributed to the animal as a general guideline?

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