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Soils

John Ives

The work of John and Robyn Ives on ‘Talaheni’, showcased yesterday at the ‘Soils For Life’ field day, was a huge vote for the benefits offered by decisions based on time spent monitoring.

A self confessed eccentric with a background in ag science, John has applied his scientific methodology to getting to the bottom of some of the most pressing problems on his property.

Clever management of soil, water, plants & animals based on his findings have resulted in:

  • the virtual elimination of dryland salinity in one of the most susceptible areas in Australia
  • an increase in soil organic carbon (SOC) from below 1% to around 4% (that’s higher than some high profile regenerative farmers in far better soils)
  • some of the best wool on the planet (based on wins in international competitions).

Read more about the Ives’ efforts in:

Talaheni Case Study by Soils For Life

Salinity Management in a variable landscape, CRC on Plant-based Management of Dryland Salinity, Salt Magazine.

Dam Salinity: A report card on our risk and progress, John Ive, Agribusiness Chain V10, p 42

Can drought really help your revegetation effort?, John Ive, Agribusiness Chain 2007.

Talehani reveg before & after

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Whenever I’ve heard Paul Newell’s name mentioned, there has been nothing but respect from those present.

A lifetime in agricultural research and as a wheat and sheep farmer in various locations has lead Paul to be well qualified to develop ‘Landsmanship’, a practice, discipline and philosophy based on an ‘applied ecological’ approach to agriculture.

Paul’s land management approach has been described as NSF (Natural Sequence Farming, a term which he coined) without bulldozers, with biological elements skilfully utilised in time and space to reinstate landscape function to essential soil, water, vegetation and biodiversity processes, within a productive agricultural environment.

Below is a link to a paper on the Natural Sequence Farming website, written by Paul, along with esteemed ecologist, Professor David Goldney.

“Natural ecology should become the highest discipline in a farmer‘s mind. Much like the disciplines of medicine facilitate healing of the body of people we love, similarly, understanding ecology can help facilitate the health and well being of the body of land and water systems we love as our living habitat landscapes, since each farmer, so we are told, wants to leave his or her land in better condition than when he/she inherited or purchased it.”

A presentation of the practice, discipline and philosophy of Landsmanship, by Paul Newell and Professor David Goldney

This post is a pictorial example of how to apply P.A. Yeomans’ Keyline-patterning for deep ripping, direct drilling or tree planting. It is meant to hopefully help clarify the subject a little for those who’d like to apply keyline patterning to their landscape in some respect, as I’ve seen and heard a number of incorrect applications and explanations floating around the internet. Nice to have a few clearer digital images too.

For a rundown on other aspects of Keyline design, a good starting point is to check out Abe Collins and Darren Doherty’s article, Keyline Mark IV, or visit Ken Yeomans site, http://www.keyline.com.au, where you can purchase Yeoman’s book, ‘Water for Every Farm’.

Finding the Keypoint and Keyline

If you would like to take advantage of the water distribution benefits offered by keyline pattern cultivation, identifying the keypoint and keyline are critical.

(Click on the first image to see a larger slideshow)

Application of Keyline patterning for:

Cultivation (i.e. Deep ripping, Pasture Cropping)

If you’ve decided to rip a paddock to help ease 100 years of compaction (having properly assessed the suitability of the landscape for this practice), or you’re direct drilling for a Pasture Crop, it doesn’t take a great deal more effort to do so on a keyline pattern. Here’s how I go about it.

Tree Mounds

Utilising keyline patterning for setting out tree rows can be very advantageous for any situation where equidistant rows are favourable, particularly where machinery is utilised in management of the inter-row.  There are two well known proponents of this method: The first is Darren Doherty, (many would have seen the image iconic image taken of the Tree Crop paddock on George Howson’s agroforestry property, Dalpura Farm), Mark Sheppard is another.

Here’s an example of how to set out a 4 lane tree belt using keyline patterning.

The same sort of approach can be taken for larger plantations, but there has to end up being some stub rows, or else the runs can get ridiculously steep and be erosion hazards in their own right.

Before you do any sort of hillside cultivation or earthworks which encourage more water to soak into a hillside, make sure you check the local environmental conditions carefully, particularly the presence of dispersive or slaking soils, saline seepage or the occurrence of slips in the local region. Entire hillsides of topsoil have been lost by ripping in the wrong place.

Disclaimer: Where water flow is concerned there are substantial risks involved. While the information and images we publish are formulated in good faith, with the intention of raising awareness of landscape rehydration processes, the contents do not take into account all the social, environmental and regulatory factors which need to be considered before putting that information into practice.  Accordingly, no person should rely on anything contained within as a substitute for specific professional advice.

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Article and Images © Cam Wilson, Earth Integral, 2013

Regrowth dry-sclerophyll forest like you see below is a common sight across the Southern Tablelands. It would be fair to estimate this growth at 10-15 years old, but in actual fact, the trees in this image at Mulloon Creek Natural Farms (MCNF) were all dated by an ANU researcher at 80 to 100. This forest is stagnant and moribund.

It’s a common story: hillsides were ringbarked, grazed and burnt repeatedly by early pastoralists of the region, until it no longer paid to do so (i.e., the decent soil was gone). With an even race for the light, the young Eucalypts take off (in this case the epicormic regrowth from the last ringbarking effort), but when the canopies of the closely spaced trees touch, they basically hit pause, limited by competition for nutrients, moisture and light.

moribund forest

Unless you’ve got the right species and are after coppiced poles, this result isn’t good from a number of perspectives, whether it’s sawlog production (insufficient size), habitat (lack of hollows and minimal niches), or soil conservation (exclusion of grass and shrub groundcover) to name a few.

Research carried out by students of ANU Professor John Field showed the effects of various treatments (thinning, exclusion, disturbance & fertiliser) on the health of the forest (stand basal area, and diversity of species). See the abstract of their findings at the bottom of this post.

These studies have informed the guidelines for carrying out Private Native Forestry (PNF). This legislation provides a sensible set of guidelines to forest management which allows a good balance between production and ecology.

Even low quality timber from a forest like this can be put to some good uses (I’m particularly interested in erosion control uses, but poles, posts, firewood, mushroom cultivation, mulch, & charcoal are a few obvious other uses) while at the same time, the health of the forest as a whole can be improved, providing environmental benefits to the landscape below and potentially the surrounding climate.

The PNF regulations allow this work to be carried out without the risk of massive fines, and a PNF Property Vegetation Plan can be easily obtained (find out more here). The following are a series of images taken at Nanima Gold, the property of Mike and Denise McKenzie where we’re carrying out some gully repair work.

Pre-felling, trees are marked as either existing habitat or recruitment trees under the Private Native Forestry guidelines. Trees are thinned to a given basal area depending on the forest type.

Pre-felling, trees are marked as either existing habitat or recruitment trees under the Private Native Forestry guidelines. Trees are thinned to a given basal area depending on the forest type.

The felled logs are lopped to a suitable size for whatever your intended use. In this case, the majority of the poles were carted down to a gully where we are building fascines as part of a Landcare sponsored erosion control project at Nanima Gold. (The fascines are a topic for another post.)

contour brush

Following the removal of any logs over 80-100mm, the remaining brush can be thrown five metres either side, creating 10m wide contours which snake around the landscape (as a quick way to mark rough contours along a slope: stand downhill, hold your arms out straight, stick your thumbs up and you’d be surprised how accurately you can find your next mark).

The brush contours become more important the barer the understorey, such as in this older project I built for The Mulloon Institute.

Flash runoff on this hillside has carried soil and organic material downhill

In that particularly degraded piece of forest, the bare path in the centre of this photo was caused by flash runoff, carrying soil and organic material downhill.

After one decent downpour, this brush contour has collected a significant amount of soil and organic debris

After one decent downpour, this brush contour collected a significant amount of soil and organic debris, acting like a hillside leaky weir.

When you create conditions in which worms are happy inside a dead forest like this, you know you're on a reasonable path

When you create conditions in which worms are happy inside a dead forest like this, you know there’s a reasonable chance you’re on the right track. I wish I could press fast forward and see what the result of these brush contours is in 50 years time.

More studies have shown the formation of hydrophobic (water repellant) soils under some Eucalypts. This is believed to be caused in part by mycorrhizal fungi, which help to direct moisture towards the roots of the associated Eucalypt, while creating unfavourable conditions for establishment of any competition.

The following pictures were taken after 80mm of rain, illustrating the extreme hydrophobicity in the Eucalyptus rossii forest at MCNF, pictured above (click on an image for a larger view).

Therefore, in these conditions the seeds of understorey grasses and shrubs either don’t have the moisture to trigger germination in the first place, or if they do germinate, they have to fight through 50mm of bone dry material to get any moisture. Hence, the relatively bare forest floor in the pictures above.

With this in mind, an extra layer of disturbance which may be useful in promoting under storey establishment is the short term integration of pigs, their rooting action helping to break up the fungal mats and reduce competition while grasses and ground covers establish (the pigs having moved on of course).

Disclaimer: To avoid hefty fines, ensure you follow relevant local legislation. No person should rely on anything contained within as a substitute for specific professional advice.

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Article and Images © Cam Wilson, Earth Integral, 2013

Private Native Forests, Southern Tablelands of NSW: Silvicultural Treatments Revisited

Simon Roberts, Chris Chartres, John Field & Chris McElhinny, 2006.

Forestry Program, SRES, ANU, ACT.

Abstract

Regrowth stands of dry sclerophyll forest extend from Central Victoria through the NSW Southern Tablelands to Southern Queensland (Field and Banks 1999). The ‘Mulloon Creek’ property, 15 km east of Bungendore in NSW is representative of this forest type. In the past, the property was extensively cleared (1890’s, 1920’s and 1950’s) and grazed (until the early 1980’s), and now supports a regrowth forest possessing a degraded structure compared to its predicted pre-European state.

In 1991, Field and Banks (and others) established a silvicultural experiment to investigate the effects of different treatments on this forest. Their preliminary findings (Field and Banks 1999) indicated treatments such as thinning and burning had little effect on overstorey or understorey growth, however fencing to exclude grazing by native and feral herbivores promoted the establishment and growth of understorey plants. The long term results, however, demonstrate that these silvicultural treatments are effective management techniques.

One-way analysis of each treatment on the overstorey (statistically in isolation of each other) reveals that thinning and burning both had significant effects on Relative Growth Rates (%BA Increment/Yr). The effect of thinning on the treatments had the most significant impact on tree growth. Over the twelve year period however, the burnt treatment had a significantly greater percentage annual basal area increment. Unlike thinning or burning, the effect on relative growth rate of exclusion fencing is not significantly different. Similarly to fencing, fertiliser had very little effect on relative growth rates of trees at the end of seven years since the application.

The understorey results were evaluated in a similar way. Only the fences treatment had a significantly higher mean richness of perennial species (21) compared to the unfenced treatment which had only 14.5 species. Fencing to exclude grazing animals has long been regarded as critical for the regeneration of native understorey plants.

Reference

Field, J.B., Banks, J.C.G., (1999). Effects of Silvicultural Treatments on Growth Rates of Trees and Diversity of Understorey in a Private Dry Sclerophyll Forest, Southern Tablelands, NSW. IFA conference “Practicing Forestry Today”, Hobart

A newly planted 5 ha mixed-Oak and hazel, truffle inoculated dehesa.

Building on the success of their well-respected business Terra Preta Truffles, the Marshalls have planted a further 5 ha of truffle orchard this season (click here for a virtual tour of Sunningdale). The system includes a wide variety of oaks, sourced from the Canberra region, interplanted with hazels which provide a shorter term truffle return. Under the guidance of top mycologists, the trees have been propagated and inoculated on farm this time around, partly because of the availability of truffles for inoculant, but also due to the very mediocre (and no-doubt concerning for many) results in the findings of a recent ANU study on the Australian truffle nursery industry.

Click on one of the images below for a slideshow of how we went about planting each of the valuable trees in ‘Mari’s Montado’ (named after Mari Korhonen who spent six months with the Marshalls last year and planted a good portion of this paddock).

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Copyright Cam Wilson, Earth Integral, 2012

The difference a farm fence can make between soils…

When you are trying to decide which method of soil improvement to take, sometimes it seems like there are as many different approaches as there are bacteria in a teaspoon of healthy soil.

This isn’t necessarily a huge problem when you’re talking about a suburban backyard scale. It’s easy in that situation to: do some aerating with a broad fork; balance the Calcium:Magnesium ratio and whatever trace minerals your soil test says are missing; build and add compost and worm castings; brew up some compost tea; add some seaweed extract, a handful of basalt rock dust, a bit of Charlie carp and the humified eyeballs of some rare mountain lion to top it off.

But what about the farmer who is planting 1000 Ha of Wheat and Rye so the armchair permaculturalists of this world can munch their organic sourdough toast while checking the next important forum posting written by someone else sitting at a computer at 10.30am. That farmer would quickly go broke if they did all the things a backyard gardener can do. So how to decide?

 

The farmer’s goal should be to turn subsoil into topsoil. That is, to be able to walk anywhere on his or her land, sink a post-hole shovel and find something resembling chocolate cake. If you’ve got chocolate cake, you’ve got good crops, whether it’s pasture, grain, fruit or veg. CSIRO scientists still say it’s impossible but I’ve seen it happen under the care of a number of our country’s best farmers (Col Seis and Ron Smith to name a couple) to know that it’s very achievable (and we’re talking years, not centuries, as you may have been led to believe).

What’s the secret? It’s plants and microbes working together. 

It seems that Nature got sick of applying bags of NPK to all the different plants on Earth and equally sick of spraying out molasses and fish hydrolysate to feed the bacteria and fungi in the soil and decided to read Mollison’s Intro to Permaculture. Principle 1: Relative Location made a bit of sense, so she conducted a Needs, Functions & Products Analysis, and in doing so recognised that plants produced more than enough sugars through photosynthesis, but needed nutrients to do so, and meanwhile bacteria and fungi were easily the most efficient critters on earth at grabbing hold of nutrient, but had a hard time finding carbs to fuel their bodies. It was a match made in heaven. The plants were put next to the microbes and have been symbiotically trading root exudates (sugars) for nutrients ever since.

What does this have to do with building soil? Those sugars passing from the plant to the soil critters are liquid carbon. Let’s take one of the exudate recipients, mycorrhyzal fungi, as an example (they attach themselves to plant roots in a symbiotic relationship). They use these sugars to produce glomalin, a protective coating for their hyphae, which is sloughed off into the soil when the hyphae dies. The glomalin is a very persistent carbon compound that ‘sticks around’ in the soil for a long time (it’s one of the main things that holds soil aggregates together).

What encourages hyphae production? You need to feed them for as much of the year as you can, and this is only possible when a plant is actively photosynthesising. That is: maximise root exudates by maximising yearly photosynthesis.

This means:

  • In pasture, an appropriate disturbance/recovery regime to maximise the growth potential of pasture plants. (See Holistic Grazing Management for further info.)
  • Different plants thrive at different times of year. A mix of C3 (cool season) and C4 (heat tolerant) plants will ensure you can take advantage of moisture and have something green and growing throughout the year (See Carbon Grazing by Allan Lauder for more info on this topic)
  • Winter cropping C3 plants (ie. wheat, oats, rye) into dormant C4 perennial pastures or summer cropping (millet, sorghum, corn) into dormant C3 pasture (search for Pasture Cropping, Col Seis)
  • A winter active groundcover under dormant fruit trees.

Using a combination of time-controlled grazing and pasture cropping, Col Seis has managed to go from the soil shown on the right of the image at top (this sample is from over the fence, 15m into his brother’s conventional agricultural paddock, who still farms the way Col used to) to the soil on the left in 15 years. (He could do it in 10 now he reckons.)

In doing so, his soil test in relation to what existed before is:

So let’s consider the management interventions related to the chemical, biological and physical aspects of Col’s soil that have lead to these results.

Chemical

The changes seen in the table above to the chemical nature of Col’s soil have been achieved without the addition of single bag of super-phosphate, nor a tonne of lime, nor any trace minerals, nor any sizable amount of compost, in 30 years. (He does continue to put out a small amount of DAP when sowing a grain crop, but has had good success with worm juice this year.) Soil nutrient amendments haven’t been the driver.

Biological

Col did put compost teas out for a little while, but then thought, “What the hell am I doing this for? Why am I adding foreign microbes from a compost pile when there is already a huge diversity suited to the conditions in the existing topsoil”. He then changed to feeding the existing microbes with molasses and fish emulsion, until he once again thought, “What the hell am I doing this for? Why am I putting food out when the plants create the best microbial food there is”. Biological stimulants haven’t been the driver.

Physical

A small aerating affect is achieved with the tines on the direct seeder that Col uses for pasture cropping, but they only impact down to about 70mm which doesn’t explain the dramatic increase in carbon down to 500mm. Soil cultivation hasn’t been the driver.

All this has been driven by the plants within Col’s pasture and cropping system. Here’s a brief summary of what they’ve done:

Biological

  • As stated above, Col aims to maximise the photosynthesis potential on his property, and hence maximises root exudates; the fuel for the life in the soil. (Winter cereals such as oats are one of the highest producers of root exudates and really give the native pasture and soil a kick.)
  • The pulse of disturbance created by time-controlled grazing, followed by a period of rest until plants have fully recovered (that is, the perennials have replaced root energy reserves) offers plenty more food to the soil food web in the form of root exudates, decaying root systems, litter, manure and urine.

Chemical

  • Soil microbes fuelled by root exudates, in particular mycorrhyzal fungi, are able to access nutrients from the subsoil that were previously tied up in a plant unavailable form. They can then transport these nutrients through their network of hyphae.
  • The test results above, which were taken down to 500mm, show not only an increase in Col’s Available nutrients, but Total nutrients have also increased significantly, suggesting the breakdown of parent rock material by the soil life.
  • Increased carbon levels also result in a huge increase in the water and nutrient holding capacity of the soil.

Physical

The growing soil carbon levels fuelled by root exudates, along with the carbon pathways created by decaying root systems, as well as the improved structure provided by bacteria glueing their butts to the particles, the fungi wrapping themselves around everyone else and the worms and other larger critters creating tunnels through the soil as they relentlessly munch-on, all help to improve the aeration, root penetration, nutrient holding capacity, nutrient availability, water infiltration and retention etc.

So does that mean that the soil improvement methods handed to us by the various soil legends that have come before (ie. P.A. Yeomans who was physical-centric, William Albrecht who was chemical-centric or Elaine Ingham who is biological-centric) are unnecessary?

Not at all.

With the right management practices, plants can do the job, but the methods that folk such as these gave to us can help to speed things along. The key thought when you are deciding which one(s) you want to spend your money on, is to keep in mind what the goal is: for plants to maximise photosynthesis and drive the system.

Therefore the practice that you choose should address the major limiting factor that restricts photosynthesis. For example:

Physical: On an area of pasture that we are developing at the moment, compaction from past practices is the major limiting factor. It’s preventing decent root penetration as well as resulting in water sheeting off. So, in conjunction with time-controlled grazing, we are implementing an initial program with a Keyline Plow using Keyline Pattern Cultivation. Good grazing and pasture cropping once every 3-4 years should maintain it from there.

Chemical: On the property of a friend of mine, he has a heavy sodic layer down about 170mm which is inhibiting root penetration. In this case, he has had an expert in the Albrecht method of soil balancing give him some advice. He has been injecting liquid calcium down to the sodic layer, which has changed the structure of the soil and resulted in root penetration a further 30-40cm in 2 years. The plants can now start to drive the system.

Biological: As far as adding biology goes, tests have recently been done by a leading University on a number of different compost teas and microbial jungle juices. Basically the results showed that if you had a bit of decent topsoil already, the compost tea made no difference. If your soil is dead, for example it might have been plowed non stop for 100 years, or perhaps there’s been excessive chemicals used on the land, then it could be worth putting some critters on as an initial inoculation.

This is just my opinion, but rather than adding foreign microbes from a bottle or even a thermophilic compost pile (which is an incredibly different environment to field conditions if you think about it), why not get hold of some soil from under a few of the best pastures in your region. Perhaps grab some from under a healthy bit of native grassland that you know of too. In my opinion they could well be better suited to your conditions.

Here’s a good story related to this topic. John Weatherstone is an inspirational farmer who has planted many thousands of trees to compliment his grazing enterprise. He had a stand of Casuarinas that were yellow and weren’t doing well. John W had a long discussion with John Field from the Australian National University about whether it could be the clay or the salt below or etc. In the end John F said, why don’t you go and grab some duff (leaf litter and topsoil) from under a healthy old stand of Casuarinas and put it around their base. John W did this to half of them and they turned green and healthy within a month. What a difference the right biology can make. (The other half began to turn green too, marching progressively away from the inoculated stand due to the root grafting that takes place, as well through the fungi which connect plant ecosystems.)

So, here’s the short version:

  1. Aim for plants to drive the soil system by maximising photosynthesis.
  2. If you’re keen to spend money to speed things up, carefully consider what the major limiting factor is, and base your interventions around this.