How to reduce fertiliser use - learning from Nature

I was astounded when I first discovered that it was possible to grow food with less fertiliser.

It’s difficult to appreciate what we can achieve as virtually all of us grow food in soil that no longer functions properly. Our soils may not show the customary signs of soil degradation: salinity, erosion, and compaction. Nevertheless, they are degraded because they lack:

Functioning nutrient recycling systems
Sufficient organic matter
Soil structures promoting root growth and biodiverse communities of soil organisms
Sufficient microbes and organic matter to release nutrients locked in mineral particles in the soil

Consequently, it’s become the norm to substitute for these free ecological services by cultivating soil, applying compost, synthetic and biological fertilisers. Virtually everybody does it.

“I can honestly say I have never ever been on a [farming] operation that is not degraded, including my own” Gabe Brown.

We can get a sense of the services our soils can provide by looking at the land managed by a small number of farmers and gardeners around the world who either benefit from growing food using traditional practices maintaining functioning ecosystems or have got their soil ecosystems up and running again!

We can also look to the past.

In Australia, Sir Paul Edmund Strzelecki surveyed soils in the southeast of the continent between 1839 – 1843; during the early settlement period. He found organic matter levels were around 5 – 10 times higher than in many soils today[1].

According to Bill Gammage, the author of ‘The Biggest Estate on Earth’, these findings are consistent with the writings of many early settlers.

“The earth has changed. Topsoil blows away, hills slip, gullies scour, silt chokes, salt spreads, soil compacts. Much of 1788’s soil was soft enough to push a finger into – naturally soft”

“Around Clermont (Queensland) the soil was exceedingly friable and rich; being unstocked and therefore untrodden, it was ‘ashy’, and the horses traveled over their fetlocks in the loose soil.”

The ground was soft, spongy and very absorbent. One inch of rain in spring and autumn, produced a luxurious growth of fresh green grass.”

Bill’s book is an impressive achievement. Bringing together extensive research into the historical records.

Reading his book you realise that the picture of Australian soils as “soft, spongy and absorbent” was not a story conjured up by a few romantic explorers. The number and similarities in the reports are too convincing, and the soil organic matter levels in Strzelecki’s reports back this up.

What’s the way forward?

It’s quite simple really! Stop doing the things that we know damage our soil and start using regenerative practices to get our soil ecosystems functioning again.

Find out how to reduce your fertiliser use by getting your soil ecosystem functioning again with our publication – Feed your Plants without Fertilisers.

References for Reducing Fertilisers

[1] Christine Jones ‘Soil Carbon – can it save agriculture’s bacon?’

[2] Original concept – Roger R.B. Leakey – Twelve Principles for Better Food and More Food from Mature Perennial Agroecosystems. Perennial crops for food security. Proc FAO expert workshop