It's all about the soil.

ANNE KRUGER, PRESENTER: You've probably heard of the term biological farming. But what exactly does it mean? Those who practise it say it's a way of farming that combines scientific methods with common sense.

In essence, it's all about the soil, the so-called building blocks of life. Biological farming aims to encourage the beneficial microorganisms in the soil. And those who've embarked on it say it's transforming their farms and their lives.

Tim Lee reports.

TIM LEE, REPORTER: It's the sort of pasture that most farmers dream about. But the grass here wasn't always so green or lush. It's three years since the Davis family, who farm near Camperdown in Victoria's south-west, took an unconventional step.

What's on top is mighty impressive, but the real action is happening underneath. Soil health is the key to what happens above. The Davises have adopted what is loosely termed biological farming.

REGGIE DAVIS, DAIRY FARMER, CAMPERDOWN, VIC.: The fertiliser that we used to put on here for the results that we were getting compared to now.

This paddock here in particular hasn't had any fertiliser since October, bar the effluent through the pivot, and due to the season that's only been going every now and again too because of the rain. So it's a huge turnaround to what's been happening. It's just healthy pasture all the time.

TIM LEE: Three years ago, Landline filmed the start of the Davis family's quest to find better ways to make their farm more productive, profitable and sustainable.

REGGIE DAVIS: We were having a lot of pest problems in the autumn where once red-legged earth mite and loosen flea would attack clover. It was starting to eat rye grass, and then we were getting to the stage where we were probably spraying three times in the autumn. And I'm thinking, this can't be right; we can't keep heading down this track.

And the other reason was in Europe, they're utilising 100 per cent of the effluent. We use water out of our second pond to irrigate through the pivots and now we're starting to make compost, so everything on the farm's going to go back on the farm.

TIM LEE: Three years on, these rows of rich composted material are the key to the farm's transformation. Most dairy farms annually produce tens of thousands of litres of effluent. It's often seen as a liability. Tony Evans sees it as an opportunity. But like any heady brew, the recipe has to be right, and that's where the principles of biological farming come in.

TONY EVANS, CAMPERDOWN COMPOST COMPANY: Most farmers have got to stay viable. The bank manager, they have to answer to. They're looking at their input costs and that's challenging them all the time.

If they can utilise what they've got first, and then import nutrient, that's a really valid way of farming. I think that's what they've got to do. They've got to challenge their thinking, challenge the way they've done things.

They can't keep doing things the way that they've done them.

TIM LEE: Part of the challenge is to understand what's happening underground. Like every great drama, there's a cast of fantastic characters - good guys and bad guys. I guess in the microscopic world there's a constant battle between the beneficial bugs and the bad bugs.

TONY EVANS: Absolutely. And I think that's the farmer's job... to understand that enough that his role is to make sure that he creates an environment for the beneficial bugs. And there's processes that he can do to encourage that. There's probably some circumstances you can't control, but there are a lot of things that he can do to minimise any damage.

TIM LEE: And that's where biological farming gets its principles from.

REGGIE DAVIS: There's a lot of interest, but a lot of people just can't get their head around it at the moment. You have to go out and source it as there's no textbook to say what to do. So, the idea is to get the specialists in the right field, which is Tony in the compost, and try and get on to someone with soil biology.

It's just a matter of working through the process.

TONY EVANS: So, if you have things growing well in the ground, then you'll probably grow different species above the ground.

TIM LEE: Camperdown Compost began 13 years ago when Tony Evans and his business partner Nick Rowson sought a way to utilise local dairy waste.

TONY EVANS: We set up a licensed facility to take organic waste streams from a couple of different dairy factories. That material was then initially used for worms and producing worm castings. And it sort of evolved into a compost site where we still use some worms, but predominantly it's for composting now.

And we met Elaine Ingham, I think, about 1999 or thereabouts and we started to then put together how we can best utilise it in an agricultural system.

TIM LEE: Landline viewers met Elaine Ingham a few years back.

NICK ROUTSON, CAMPERDOWN COMPOST COMPANY: Looking at soils, looking at a healthy system and pulling the soil apart and seeing what biology's there and then looking at a depleted soil that probably hasn't got a lot of carbon that's tight, that the rainfall doesn't go in. It runs off all of these problems, and looking at the biology in that soil and then... some basic underlying principles of what sort of biology should be in a healthy soil.

I really like the approach that you can see it, look under a microscope and see these are the little critters that should be there and they're not in this soil and that's why it behaves in this way.

TIM LEE: When Gary Zimmer, a world leader in the field of biological farming, visited Australia earlier this year, his various seminars were sold out.

GARY ZIMMER, AUTHOR & EDUCATOR: Biological farming is actually a term - I'm a diary nutritionist by training and got into what we call biological farming, and to me it's focusing on the fact that the soil is alive, it's full of biology and it's a living system.

TIM LEE: John Lillico is a dairy farmer in north-west Tasmania who in recent years has converted to biological farming.

JOHN LILLICO, BIOLOGICAL FARMER, TASMANIA: In the past we didn't really understand what microbes were in the soil and what function they had. We do now. And so we farm with complete respect for those microbes, you know. There's as much life under the soil as there is above it and we need to respect that and we need to work with that.

TIM LEE: The surge of interest in biological farming is partly explained by the ever-increasing scientific knowledge of what happens in the soil at microscopic level.

GARY ZIMMER: I remember that time when I first started using that word, I just wanted people to recognise that the soil was alive. And so it's really a combination of minerals, of soil life and we have not spent enough time - and to me the future is to really: get the biology to work in the soils, it's going to clean up things, it's going to make our crops healthier and it's a way to fix our soils to have better use of water. And right on down the line is biology is in things that's going to fix this planet.

TIM LEE: As a farmer and agri-businessman, Gary Zimmer's bestselling books on biological farming launched him into becoming an educator of biological agriculture.

ANDREW ANGELINO, BIOLOGICAL FARMER, MT GAMBIER, SA: The crowd here today, I think there's some potato growers and a few vegetable growers, but the majority of the crowd's us dairy farmers down there and we've always wanted to meet Gary Zimmer, being probably the number one biological farmer promoter in America.

He's basically written the book and the bible that we all try to aspire to.

TIM LEE: Gary Zimmer talks of balancing the soil and its nutrients and working with nature, and for many farmers it was the global financial crisis that forced them to question aspects of conventional farming.

DECLAN MCDONALD, DEPT. PRIMARY INDUSTRIES VIC.: I think the price shock of 2008 really brought that message home starkly to a lot of farmers. When the price of oil went up, the price of fertilisers went up and I think the future then became writ large for a lot of producers when they thought, "OK, well if this is what's going to happen to fertiliser prices in the future, am I going to be able to respond, am I going to be able to maintain profitability in the face of this or is there a better way to farm?"

TIM LEE: However, changing from a tried and true system of production still requires a leap of faith.

JOHN LILLICO: They are cash-strapped, I suppose. The industry's not particularly robust. And they're being frightened to change direction because they know the course that they've been going down has paid the bills and they're nervous about changing.

TIM LEE: Like the Davis family, John Lillico has seen the clover come back and a healthier milking herd.

JOHN LILLICO: I'm quite sure that the way we're going is the way of the future. It certainly wasn't a sustainable system, the way we farmed before.