DIRTY BUSINESS: Mike Harrison in front of a stand of cane grown in soil in which pineapples were grown previously.
DIRTY BUSINESS: Mike Harrison in front of a stand of cane grown in soil in which pineapples were grown previously.

Taking care of the engine room that drives growth

SOILS are an incredibly complex interwoven system of nutrients and micro organisms.

Plants depend on the right balance of all these things to be able to grow and produce a profitable crop.

Growcom has been holding a series of soil health workshops funded by Burnett Mary Regional Group, throughout the Wide Bay region, the latest of which was held on the Buchanans' Sandowne farm.

Growers came from farms growing small crops, passionfruit, sugar cane, pineapples, citrus and macadamias.

Presenter Mike Harrison, who runs Wide Bay Compost, said that as people dealing with soil on a daily basis, participants tended to ignore the most important issues affecting crop production.

"We ignore the 'engine room' that drives growth," he said.

"What happens to the organisms in the soil is the crucial factor."

Mr Harrison said soil organisms varied from microscopic to visible, such as worms and insects.

"They form a symbiotic relationship, relying on each other," he said.

"Some soil organisms are pests but the vast majority are 'good guys'."

Mr Harrison said plants were as much a part of the system as anything else.

He said plant roots produced a sugary liquid that attracted both good and bad organisms but, he said, if there was a balance in the soil it evened out.

"As many farming practices diverged towards a reliance on harsh fertilisers, soil biology tended to be under stress," Mr Harrison said.

"Soils tended towards either fungal or bacterial dominated."

A healthy balanced soil food web could help to minimise the effects of many plant pathogens, he said, and by improving soil structure, maximise water absorption and retention and keep nutrients in the soil in a form available to plants.

"Good soil structure is vital to enable air, water and nutrients to move through," Mr Harrison said.

"This provides easy access to the soil micro organisms, including fungi."

As they moved through the soil, the fungi and other organisms opened up the soil, he said. Harsh farming systems could readily break down the micro organism content, especially the fungi.

Mr Harrison said the traditional rule of "if you have a few worms, then the soil is not too bad" still held pretty true.

"Worms are good indicators of soil condition," he said. "A good compost mix is probably as good as you need to apply, as it is beneficial to most soil organisms."

A good healthy soil allowed for quicker recovery from major events, such as flood, where a lot of the organisms would have been killed.