Tuesday, April 21, 2009

Natural Sequence Farming deserves widespread testing!

"Natural Sequence Farming contains three valuable elements for combating climate change. All three promise to help farm productivity and longevity as well... it would be very useful for a government body to take over some whole catchments and implement a systematic test of Andrews’ theories over the whole river system: for example, the Hunter River (following the closure of the coal mines there!), or a tributary of the Murray or Darling river. With appropriate compensation and consultation with the farmers involved, and assuming the results are positive, this could lead to the complete renewal of Australia’s inland ecosystems."

Back From The Brink: How Australia’s Landscape Can Be Saved
Peter Andrews
ABC Books 2006

Peter Andrews’ widely acclaimed book Back From The Brink rests on his accomplishments in restoring and sustaining farm landscapes on his own properties, as seen on ABC TV’s Australian Story and Catalyst . Despite many controversies about aspects of his Natural Sequence Farming technique (especially the use of species considered noxious weeds), his analysis of the Australian landscape, and his remedies for the unquestionably disastrous European settler farming practices are gaining widespread interest. Andrews has recently released a follow-up book, Beyond the Brink (which I hope to review in due course).

By using his own trial-and error experience, combined with wisdom learned from many other sources including scientists, farmers, and the accounts of the land from early European explorers of the continent, Andrews has developed techniques to mimic the way he believes the landscape held water and remained fertile prior to human settlement by the aboriginal peoples.

Because Australia is so flat and rainfall so intermittent, Andrews reasons, for the land to support the teeming wildlife that early explorers reported, there must have been a special way that water flowed through the land. After 150 years of sheep and cattle farming, land clearing and bad management, the land is dried out, facing massive salinity breakouts, and crops are failing.

Let’s listen to how Andrews explains his book’s purpose:
“Since the Australian landscape functioned perfectly well on its own for millions of years, we ought to be able to solve the landscape’s current problems by somehow reinstating whatever it was that enabled the landscape to function so efficiently then.”
He describes the ancient landscape’s patterns:
“In the broader floodplains, water entered the ground through sandy, gravelly ‘recharge areas’ and was stored in the layer of sand and clay that underlies much of the continent. In the floodplains themselves, water travelled in creeks and rivers that… were elevated above the surrounding sediment.”
(He later explains that rivers had banks holding them higher than the surrounding land, banks which were built by sediment carried in the river.)
“A true floodplain was what its name suggests: a plain that was periodically flooded. Rivers and creeks did flow across the floodplains, but they weren’t rivers and creeks as we know them. They hadn’t gouged out a channel. They flowed over the surface of the plain, not through a channel, which meant that, whenever there was enough water, they’d spread across the plains on both sides, which, as we have seen, were lower than they were, and the water would soak into the ground.”

Before European settlers came, river systems looked more like long strings of wetlands and only slow-flowing water channels. Reed beds, clay banks and diversion routes meant that the water flowed right across the surface of the landscape, saturating the soil rather than flowing over the surface. Now days our rivers resemble deep drains, with the water down the bottom of steep banks, running straight to the sea. Because the water in the rivers is so low, the underground water table falls. Where irrigation water is pumped onto areas, it pushes down on the salty water lower in the water table, which is then squeezed sideways through the clay to emerge somewhere downhill, damaging soil and crops. Andrews’ techniques aim to keep a layer of fresh water on top of the salty ground water across the landscape.

The book explains that this view of the cause of salinity is different to traditional views, which suggest that salty water rises of its own accord, for example, or where there are no trees to use underground water and keep the water table down.

Natural Sequence Farming is not just a matter of water flows. To hold the water in the soil, and pull it up so that it doesn’t fall down deeper (squeezing the lower saline water sideways and to the surface downhill), it is vital to keep up the vegetation. Andrews also recommends the heavy use of mulching. It is partly here that he recommends the retention of weeds (even nodding thistle, and serrated tussock). He says they thrive on infertile ground; when they have been slashed down and mulched for a while, the ground will regain fertility and grasses will take over again. So for thistles, “The fact that thistles are growing in a paddock shows that the thistles need to be growing there. In other words, it shows that the soil lacks fertility and needs to be regenerated. Thistles do the job perfectly. What’s needed when soil lacks fertility is an aggressive plant that, one, grows rapidly and adds organic bulk to the soil and, two, deters animals from grazing around it, thus enabling the surrounding soil and vegetation to recover. Thistles do both superbly.” While many might try to avoid introduced weeds like thistle, this technique has the advantage of working with the existing environment and not against it. Just as controversially, Andrews suggests willows can be planted as a fast-growing river bank stabiliser.

These uses of introduced weeds are one of the most controversial aspects of Andrews’ recommendations. But he swears by them, so it may be worth abandoning our preconceptions to try out his techniques on a broader scale.

Andrews claims that the destruction of Australia’s natural ecological balance began seriously with the advent of aboriginal "firestick farming" some 50,000 or more years ago. This also appears controversial. A debate about whether aborigines practiced firestick farming at all in areas like Victoria's mountain forests is currently being undertaken among fire experts (1). While there is a chapter called “Australia’s deserts are all man-made” the book does point out that Australia’s dry situation is in part caused by its ancient separation from Antarctica. When these continents were joined as part of the ancient continent Gondwana, rivers would have flowed across Australia from the Antarctic mountains. Since separating from Antarctica (and moving north into hotter latitudes), ecosystems in Australia have evolved to survive with low rainfall.

Andrews contends that “there were once arid rainforests in Central Australia that survived on as little as 125 millimetres of rain (around 5 inches) a year. The aborigines destroyed them with fire, and where these rainforests once stood there is nothing now but desert… it’s a sobering fact that there were no deserts in Australia before the Aborigines arrived”. As the book is largely unreferenced, this reviewer finds such statements hard to judge: are they simply Andrews’ own educated guess, or a well established view of natural history? A quick web search shows some support for Andrews’ thesis (2).

Andrews also claims his methods will work virtually anywhere in Australia, whether on the coastal plain, the high country, or the inland plains. It’s not clear how far this extends into the wet north, the desert areas and so on, and what modifications of his theory may need to be observed with each area, but that is a minor problem.

Andrews also assumes that farmers will continue to farm great numbers of sheep and cattle. While this currently seems self-evident and desirable to most farmers, it seems unlikely that in the face of climate change our ruminant (sheep and cattle) flocks can be maintained at anything more than a fraction of their current size: they release huge amounts of methane, a very potent greenhouse gas. If farmers abandon ruminants – or all hard-hooved animals – on a wide scale this in itself could help with restoration efforts, as their hooves damage the soil structure and water courses considerably.

Despite the controversies I have mentioned, Peter Andrews’ Natural Sequence Farming contains three valuable elements for combating climate change. All three promise to help farm productivity and longevity as well. Firstly, the use of energy intensive, fossil-fuel-derived fertilisers and pesticides can be largely phased out if his system works (also getting rid of a huge cost for farmers). Secondly, the use of mulching instead of ploughing and fertilising locks a lot of carbon into the soil, whereas ploughing and clearing enables it to return to the atmosphere much faster. Thirdly, restoring the water flows of natural ecosystems allows a wide variety of species to return to the landscape – plants, animals, birds and insects. This protects biodiversity, which Andrews sees as an essential element for his system, and certainly crucial for natural systems to survive changing climate.

There is urgency in the book. Andrews thinks that Australia is probably going to have another wet period soon (on a 50 to 100 year cycle of drought and wet). As good as this may sound in the middle of the current drought, our poor water flows mean that big new rainfalls might push even more salt to the surface, destroying huge areas of farm land.

While debate about the use of noxious weeds and the future of cattle and sheep farming will continue, the other aspects of Natural Sequence Farming deserve to be used and tested over wide areas of Australia’s drought-stricken inland. At this stage, in many drought and salinity stricken catchments there is not much to be lost and a lot to be gained.

While many farmers will baulk at such radical changes to their practices, given the financial risk involved, it would be very useful for a government body to take over some whole catchments and implement a systematic test of Andrews’ theories over the whole river system: for example, the Hunter River (following the closure of the coal mines there!), or a tributary of the Murray or Darling river. With appropriate compensation and consultation with the farmers involved, and assuming the results are positive, this could lead to the complete renewal of Australia’s inland ecosystems.

In the meantime, the efforts of community groups can be seen online at the Natural Sequence Association website and Peter Andrews’ ongoing activity at his website.

Footnotes
1. See here and here for a taste of the debate on fire management (including aboriginal practices) at James Woodford's Real Dirt blog.
2. See here for the abstract of one paper describing environmental pressures leading to desertification of Australia’s interior. For an argument that human activity may have impacted, see here.

2 comments:

  1. Ah good. Agriculture is finally dealt with as part of the strategy against climate change. Shame you guys have closed your eyes to the role of GMOs in reducing climate change. Continued irrational opposition to them is no way to fight climate change.

    ReplyDelete
  2. Can you provide a link perhaps to something explaining how GMOs help? I'm not against genetic engineering in principle but I am skeptical about the current agribusiness genetic engineering -- it's donee for their profits, and not understood well enough to be fully safe yet.

    ReplyDelete

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