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WEBINAR Q&A

Below are responses to the questions asked of our panel members by participants during the National Landcare Facilitator/Soils for Life Regenerating Australia's Soil Health three-part webinar series of 22, 29 May and 5 June 2013.

Jump to >> Mike Grundy >> David Marsh >> Colin Seis >> Shane Joyce >> Tim Wright >> Bill & Rhonda Daly

Visit out webinar page to view the webinars and download presentations.




Mike Grundy

QUESTIONS OF MIKE GRUNDY
Leading CSIRO’s research into observing and understanding trends in Australian landscapes

1. Can you please give an indication at what soil pH nutrients are leached through the profile in Northern Australia?

2. Our major issue in SA part of River Murray to mouth has been acidification of soils around the river and lake edges. Is this different from 'general' acidification?

3. Mike, Have we got the balance right in the topics being researched? In the past we have seen periods of "big issues" - we have seen acid soil research, then salinity, now C and nitrous oxide, we (in response to funding bodies) dont seem to balance research "areas" very well. How can this be done better?

4. Are there any areas in Aust. where soils are being affected by the wrong type of production is being attempted - for example cattle in areas that are subject to repeated droughts?

5. Can Mike discuss the statement that inputs need to be added back in after they have been removed (in wool/livestock etc)? How do you manage nutrients i.e. replacing nutrients removed in produce?

6. There has been a very strong focus recently on Biochar and inert soil carbon. Has there been sufficient focus on carbon that is digestible and therefore able to drive soil biology? Have we got the balance right between inert and non-inert carbon?

7. Why some managers are able to see soil carbon levels increase by 1 to 2 tonnes per year (lots of the case studies in ‘Soils for Life’ have measurements of this order), yet scientific reports say that such levels of C sequestration are unattainable?

8. How does fire play a role in soil health?

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David Marsh

QUESTIONS OF DAVID MARSH
Grazier from near Boorowa in NSW, former board member of the Lachlan CMA, Landcare member.

9. What is the difference in stocking rates between 'conventionally' managed farms and your farm David? Did you have to reduce your stocking numbers to get started?

10. What is the role of tree cover in soil health - does removal of trees assist management or does it cause other problems for soil health? / David, what benefits have you noticed to the farm's soils and water infiltration and retention capacity by planting of trees into or around your pasture areas?

11. Do the weeds become less when soil is right?

12. David, you said that managing the farm to increase the biota has been good for business. I recall that you said that input costs decreased, for example, eliminating the need to bring in feeds during drought. Are there are ways that it has been (measurably or otherwise) good for business?

13. Have you completed comparative soil tests to determine mineral changes?

14. What decision making tools does David use in adjusting stocking rate to match rate to feed on hand?

15. How [did you] get rid of Pattersons Curse?

16. Great presentation from David Marsh - is there any case studies from WA with similar works on regeneration of typically cleared and grazed landscapes. Also looking at cropping/grazing enterprises, or places to look for this information.

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Colin Seis

QUESTIONS OF COLIN SEIS
Grazier and cropper on the property Winona, near Gulgong in NSW. Colin is the developer and leader in ‘Pasture Cropping’.

17. Could you please talk about some of the barriers you've heard about/encountered to introducing this method on any property?

18. Is there any experience of using these techniques on other soil types, especially poor/light soils, or on steeper, rockier soils?

19. Did native grasses result from planting seeds or natural regeneration?

20. How long did it take to benefit from the changes you made?

21. Has the carbon on Col's farm been speciated? eg labile and so-on

22. What is the market for native grass seed? Who buys it?

23. Have you also encouraged bushland regeneration and is this needed to support pasture cropping?

24. Sounds good but if you haven't had animals then you'd need to put in a lot of infrastructure. Please comment.

25. Have there been any testing of the VAM levels in the soil in the pasture cropping system?

26. A question for Col, what are the sound ecological principles he employs on his property?

27. What starter fertiliser was used in the cropping system and what is being used now at sowing?

28. My question is to Colin: did you monitor soil water status at different depths and did you also observe any changes in soil erosion compared to neighbour’s soils?

29. A question to Col and Shane: great stories, and seem like a no brainer to switch to less inputs. So why not more people follow your practices? What is the barrier for adoption? (is it lack of information, scepticism, etc)

30. Are you using herbicides / pesticides with your cropping programs?

31. Are there different responses on different soil types? Has there been soil mapping on the properties?

32. Does Col have a itinerary for workshops re pasture cropping?

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Shane Joyce

QUESTIONS OF SHANE JOYCE
Grazier from Dukes Plain on the Brigalow Belt outside of Theodore in Central Queensland. Shane is successfully managing his grazing and regenerating vegetation to improve soil health and deliver increased productivity.

33. What are the most efficient and effective ways to improve the microbial health of soils?

34. What sort of pasture species have been able to grow under the brigalow? Are these natives or improved pastures?

35. For Shane - does the pasture on the cleared brigalow country dry off later than on the uncleared country?

36. How has weed management evolved with the changes in land management.

37. Shane - can you provide some more details on 'biodynamic preparations'? (Multiple questions on this.)

38. What type of systems are you using to measure the improvements?

39. Was there a side-by-side controlled comparison done for the biodynamic preps?

40. A question to Col and Shane: great stories, and seem like a no brainer to switch to less inputs. So why not more people follow your practices? What is the barrier for adoption? (is it lack of information, scepticism, etc)

41. Question for Shane. Do you use fire at all to support your farm management?

42. Where do you get the cow horns for the biodynamic preparation?

43. Are there different responses on different soil types? Has there been soil mapping on the properties?

44. How would you regenerate clay soils/heavy clay soils in semi-arid climate?

45. Gypsum is used in periurban areas for breaking down clay soils - is gypsum not appropriate to the rural setting?

46. There was a great study done recently in the Swann Catchment area south of Perth on science and benefit of Biodynamics. Very good data?

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Tim Wright

QUESTIONS OF TIM WRIGHT
Grazier from Lana, near Uralla in NSW. Tim's monitoring of rainfall and stocking rates provides evidence of how his holistic practices have supported an increased carrying capacity regardless of rainfall.

47. Does Tim use any software packages to manage pastures, paddocks, grazing and stock rotation?

48. Has the rainfall efficiency been reflected in stock quality and weight/ha and financial returns/ha?

49. If carbon sequestration is the main game for these changes what consideration is given to the toxicity of herbicides to the beneficial micro-organisms like mycorrhizas from glyphosates? How beneficial is the use of fulvic acid in conjunction with glyphosate in protecting these essential micro-organisms from this negative effect?

50. Did you actually "grow" soil or was it the bulk density of the soil reducing. What was the base reference point (depth) to determine the "growth of soil"?

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Bill & Rhonda Daly

QUESTIONS OF BILL & RHONDA DALY
Grazing and cropping on the property Milgadara, near Young in NSW. Measurement and monitoring have been key to the Daly's understanding of their landscape, enabling them to balance soil structural, biological and mineral components.

51. Where do you obtain the input biomass to create your compost / tea / humus builder? Does this source and quality vary seasonally or annually?

52. What changes in organic carbon have you measured using soil tests?

53. Did you actually "grow" soil or was it the bulk density of the soil reducing. Or what was the base reference point (depth) to determine the "growth of soil"?

54. More on the composting - are the inputs organically grown or from fertilised crops?

55. Are you not transferring nutrients from one landscape to another by bringing in nutrients- no issue with using them but what about the big picture?

56. If carbon sequestration is the main game for these changes what consideration is given to the toxicity of herbicides to the beneficial micro-organisms like mycorrhizas from glyphosates? How beneficial is the use of fulvic acid in conjunction with glyphosate in protecting these essential micro-organisms from this negative effect?

57. Has anyone heard of the process of injecting tractor exhaust emissions back into the soil as a means of sequestering carbon / reducing emissions - I would think it may be deleterious to soil organisms?

58. Do Bill and Rhonda consider the effect of importing nutrients in compost feed stock in their overall nutrient budget?

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Mike Grundy

MIKE GRUNDY

Leading CSIRO’s research into observing and understanding
trends in Australian landscapes


DOWNLOAD WEBINAR PRESENTATION (3MB)


1. Can you please give an indication at what soil pH nutrients are leached through the profile in Northern Australia?

As is often the case, I will start the answer with – it depends! Soils generally carry a negative electrical charge which allows them to attract and hold positively charged minerals and nutrients. The charge is strongest on the surface of the clay particles, on some mineral oxides and in the organic matter. In a soil test, this overall property is measured by the Cation Exchange Capacity or CEC. In some soils, especially our very weathered soils in the tropics and sub-tropics, the charge is weak and changes with pH. At a pH around 4-4.5 and perhaps a unit higher in the subsoil (although it can vary around these values by a pH unit or so), a point is reached where the charge is zero; below that pH, the soil then becomes positively charged. Organic matter also has a zero net charge around pH 4 but very high levels of charge at a neutral pH. At the point of zero charge, this part of the soil has its lowest level of ability to attract and store either positively charged or negatively charged ions.

Of course these matters are never that simple.
      1. The level of organic matter has a strong effect – moving the point of zero charge to lower pH values. P fertilisers have the same effect and the level of iron and aluminium oxides in the soil, the opposite effect. So again, the higher the level of organic matter, the better the nutrient retention.
      2. In some tropical soils, it is common to observe net negative charge in the surface and net positive in the subsoil – partly due to the influences mentioned above. Some of these soils can then hold significant quantities of nitrogen in the form of nitrate in the subsoil and slow its movement into groundwater. On the other hand, these subsoils can also hold and bind phosphorus to the point it is unavailable for plants reducing the effectiveness of fertilisation.
      3. The other important point to make is that highly acid soils (wherever they occur) have many other problems – chief of which is toxic levels of aluminium and manganese. The stunting of roots on one of the slides in the presentation was caused by this (from Chris Gazzey in WA). Some plants are more tolerant of this but other issues then become important including low levels of calcium.

I have not been able to find a simple fact sheet on this – perhaps someone who is reading this can find them. To manage and avoid the problem, it might be useful to look at these sheets on acidification:
http://www.nrm.qld.gov.au/factsheets/pdf/land/l45.pdf
http://www.ces.vic.gov.au/__data/assets/pdf_file/0013/124420/factsheet7.pdf
http://www.agric.wa.gov.au/objtwr/imported_assets/content/fm/small/nw16_soil%20acidity_lr.pdf

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2. Our major issue in SA part of River Murray to mouth has been acidification of soils around the river and lake edges. Is this different from 'general' acidification?

As I explained in the webinar, this is a quite different process. This document: http://www.environment.gov.au/water/publications/quality/pubs/guidance-for-management-of-acid-sulfate-soils.pdf has a good description of this issue.

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3. Mike, Have we got the balance right in the topics being researched? In the past we have seen periods of "big issues" - we have seen acid soil research, then salinity, now C and nitrous oxide, we (in response to funding bodies) dont seem to balance research "areas" very well. How can this be done better?

As I think I said in the webinar – yes and no. Each of the ‘big issues’ have seen important progress in our understanding of some part of our land management systems. If we keep approaching these issues in the sense that we are managing an interacting system, then we can get value out of the shifting focus. On the other hand, I worry sometimes that we think we have ‘solved’ a particular problem and then move on. Discussions around soil health, landscape management and so on (like this webinar), keep our eye on the full system and increase the chance that we will benefit from the focus on particular aspects of the system.

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4. Are there any areas in Aust. where soils are being affected by the wrong type of production is being attempted - for example cattle in areas that are subject to repeated droughts?

Undoubtedly and perhaps there will always be some of this. It has been interesting to see lately though, that we are making progress on matching production to land – and to changing the way we run those production systems. David showed in his talk that a sensitive and sensible approach to the pressure we exert and when we exert it can produce sustainable land use. In the catastrophic floods in south-east Qld, there was much less run-off from agricultural lands than we have seen in the past because land management practices have substantially improved.

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5. Can Mike discuss the statement that inputs need to be added back in after they have been removed (in wool/livestock etc)? How do you manage nutrients i.e. replacing nutrients removed in produce?

The simple answer is that we need a nutrient budget for the farm – NRM bodies, extension agencies, advisors usually have this sort of information which you can tailor to your mix of enterprises.

Why is this needed? The soil has a finite store of the essential elements required for plant growth (there are essential elements for livestock but this is a much rarer issue). Some elements can be provided ‘free’, for example nitrogen fixed from the atmosphere by legumes and the carbon plants accumulate and pass to livestock comes from CO2 in the atmosphere, but in each case, these require adequate levels of the suite of essential plant nutrients.

When we remove plant material or feed it and then remove the livestock, we are removing these elements from the system – and somehow they must be replenished. (An aside: we are also removing alkalinity when we do this, so we leave a little more acidity each time – which is important in less resistant soils). On the other hand, we may overdo the replenishment and leave too much in the soil which creates problems in the soil and in the environment more generally. The Australian Phosphorus story is interesting. As a broad generalisation, we have added too much in the south and too little in the north. The northern issue developed because, unlike much of Australia, we inherited some heavy clay soils with naturally high levels of P which we then ‘mined’ for decades. There has been a lot of effort lately to develop systems where we monitor our soils, become aware of the deficiencies and sufficiencies and manage to get back in balance over time. This leaflet (http://www.tia.tas.edu.au/__data/assets/pdf_file/0010/356608/nutrient-management-leaflet-6.pdf) gives you an idea of a budget for farms in Tasmania but you can find many examples on the net.

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6. There has been a very strong focus recently on Biochar and inert soil carbon. Has there been sufficient focus on carbon that is digestible and therefore able to drive soil biology? Have we got the balance right between inert and non-inert carbon?

This is an interesting question and is similar in some ways to the question on the balance of research topics. Although biochar has been of interest for a couple of decades in the scientific discussion (and we have long observed the high levels of charcoal in our northern soils), the increase in interest has come since we need to find a broad range of ways to mitigate the production of CO2 which has accumulated at such alarming rates in the atmosphere. A comprehensive and cross-sectoral approach is seen to be needed to reduce the atmospheric levels of greenhouse gases. So land based sequestration – especially over the next few decades – is an important component. We know that charcoal can ‘fix’ carbon so biochar was attractive from that perspective – as long as you can build it into systems which take us forward (some suggested uses seem to rob Peter to pay Paul). The associated question around biochar – and where much of the research is now – is the extent to which it can have additional beneficial effects. The results so far suggest that some forms can.

The other side of the question posed above is whether this has been to the detriment of the focus on the more dynamic forms of soil carbon and the way it is integral to our land management. Personally, I don’t think so – I tend to see them as quite separate areas of focus. More generally, the interest in soil carbon as a form of sequestration, has allowed us to increase the focus on soil carbon and organic matter, their value and the close interconnection with land management; a message soil scientists have been keen to send out for a long time.

Link to an interesting video: www.agriculture.gov.au/ag-farm-food/climatechange/climate/communication/factsheets-case-studies-and-dvds/transcripts/transcript-of-the-biochar-video

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7. Why some managers are able to see soil carbon levels increase by 1 to 2 tonnes per year (lots of the case studies in ‘Soils for Life’ have measurements of this order), yet scientific reports say that such levels of C sequestration are unattainable?

A hard question to answer in a paragraph! First of all, the science does not say that these levels are unattainable. What they have said to this point was that in reviewing long term trials and detailed studies the sequestration measured over time is more modest than these levels.

First the underpinning concepts: With the exception of the inert forms of carbon, carbon cycles through our natural and agricultural systems exchanging CO2 with the atmosphere daily. The amount that is retained in the soil is the balance between the biomass that is produced and left in the soil, the amount of decomposition that occurs through biological activity and the amount of carbon that is removed through harvest or loss. A predictable balance is maintained in our natural systems between the climate and soil / vegetation type.

Agricultural land use typically results in a loss of carbon with clearing, tillage and harvest (although we have some soils where levels were so low that agriculture through fertilisation and increased biomass has increased the carbon levels above the original level). The change can be slow in some soils; eventually a new balance can occur. To change this, we need to change the balance of the cycle – increase the biomass or decrease the harvest or alter the decomposition (this last factor is challenging). And we need to maintain this over time.

There is a lot of carbon in the soil (more than in the vegetation and atmosphere combined) and there has been a general decline with agricultural development so there seems to be room to regain some ground, capture more CO2 and reduce atmospheric levels. In evaluating our capacity to do this, scientists have been cautious in reviewing what we know to ensure that the reliance on the use of soil carbon has a strong evidence base. This means that the focus has been on repeatable measurement, long term studies (carbon levels fluctuate over seasons) and ensuring statistical rigour – is what we measure a real result? Much of what you have seen published from scientists to now has been based on existing studies; over the last few years, there have been new studies and a new emphasis on measuring soil carbon across major land management systems and environments and especially some systems where we did not have enough existing measurement – like perennial pasture systems. The first results of this are being prepared now and should be out soon. It is important to note that again these will be new baseline measurements; we need to measure how they are maintained over time.

So what needs to be in place to get high levels of sequestration? The highest level of carbon that can be achieved in a specific system occurs where we are using our resources most efficiently – and water is the common driver. If we inherit an inefficient system and can improve the efficiency with which the water and nutrients are used, then we can increase the soil carbon balance because we capture as much carbon as this system can produce. If the existing system had low efficiency, then large gains can be made. These then have to be sustained over time. If efficiency falls then the balance between accumulation and loss will change and soil carbon levels fall. If, however, we inherit an already efficient system, then we have little room to move – and we could then only build soil carbon by changing the system itself eg. from cropping to a perennial pasture system. For each system, there is a ceiling which can’t be changed except by changing the system. (As an aside, it is not enough to measure change in carbon % to measure change. If soil carbon increases, the density of the soil tends to decline so that a % measure is gives us the proportion of a declining total mass. You need to measure both the % and bulk density of the soil so that we can measure the change in the total mass).

As a final comment – scientists are always interested in the opportunities for new perspectives and improved understanding. We are looking at some of the new systems now and are always interested in doing more.

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8. How does fire play a role in soil health?

Another question which deserves a long response, to which there are many dimensions and no simple answers!

Fire is part of the evolution of most but not all Australian ecosystems and therefore it interacts with soil properties. The exceptions are rainforest communities where fire is rare or non-existent and where nutrients are cycled rapidly.

There is some interesting revisiting of the history of land management prior to European settlement currently and many of our ideas of the degree of intervention are being challenged. It seems clear that fire has been part of soil / vegetation dynamics for thousands of years at least. Low intensity fires are common and may always have been. They only heat the upper centimetres of the soil. More intense fires have a deeper impact – perhaps to 50cms or so. The heat generated will also be modified by the clay content of the soil and the level of soil moisture. There will be indirect and direct effects. These include:
      1. Loss of vegetation and soil cover – which exposes the surface to erosion. Spectacular erosion events have been observed after wildfire which pollute waterways but also remove valuable surface layers of the soil;
      2. The loss of vegetation also means that nutrients (mainly N and P) have been removed from the system – and from the soil – through smoke and gas.
      3. The role of the ash. Ash is alkaline so pH may increase. There is often a release of nutrients from mineralisation of the ash and altered organic matter – which can bring a flush of growth after a fire.
      4. With very intense fires, some permanent changes to the soil materials can occur and at these temperatures, large nutrient losses occur and the nature of the soil itself changes. In most of our natural systems, fire can’t be avoided and, in any case, many vegetation communities depend on them. Nevertheless, over time, there is a steady loss of nutrients.




David Marsh

DAVID MARSH

Grazier from near Boorowa in NSW, former board member of the Lachlan CMA, Landcare member.


DOWNLOAD WEBINAR PRESENTATION (3MB)


9. What is the difference in stocking rates between 'conventionally' managed farms and your farm David? Did you have to reduce your stocking numbers to get started?

These days I only talk about what is the appropriate stocking rate for the conditions prevailing at a particular time. Generally, I would recommend people to enrol in a course such as Holistic management, RCS, Principle Focus, so they receive the appropriate training to enable them to plan for themselves.

I think I need to add a bit to my answer from the webinar. It is very hard to give general answers to these specific questions, my answers are what we did in our area with the soils here and our local climate, they should not be used as recipes for others but should be adapted to your own circumstances. We took a decision to reduce our core numbers by about a third. Do not forget we had stopped cropping and this added more grazing area. We felt it was not logical to try and run static numbers in a very variable climate. We made this decision to ease the pressure we felt our former management was having on our land and to stop the annual roller coaster from euphoria to despair that happened in every season when our numbers of stock were very high.

The logic was that if we had a big excess of feed we could either trade some stock or run some agistment to recycle the extra biomass while having a source of no capital risk cash flow.

The longer recovery periods used in planned grazing allows the plant community to fully express itself every time it is trying to grow. This leads to soils with higher organic matter due to the larger root systems. Soil structure improves, water holding capacity is increased, there is more food for soil-borne biota; the whole system quite quickly begins to work better and the resources used to achieve this are all free, namely, sunlight, rainfall and time.

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10. What is the role of tree cover in soil health - does removal of trees assist management or does it cause other problems for soil health? / David, what benefits have you noticed to the farm's soils and water infiltration and retention capacity by planting of trees into or around your pasture areas?

I do not have any data on this question. It is thought that original tree cover here was perhaps 20%. Revegetation on this farm has taken woody vegetation from 3% to 15%. This means that 85% of the area is grassland. The arrangement of the seeded and planted trees has resulted in a patchy landscape which is an attempt to mimic former vegetation, although a pretty rough attempt.

The habitat, shelter and litter as well as the root systems are all positive in bringing more nutrients into the available pool. The depth of tree roots is important in this. As well as this, grass communities that are managed for full recovery also have much bigger root systems accessing new material at greater depth.

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11. Do the weeds become less when soil is right?

The physical soil has inherent limitations depending on the material from which it is formed. However it is the plant community interacting with all the teeming multitudes of life in soils that also can influence soil fertility due to the carbon rich structure of the plants derived from the reaction of photosynthesis. When the needs of an organism are met in the community, it is likely that it will begin to be represented. Similarly when soil conditions alter to a state that is unfavourable to a species such as Patterson's Curse it will begin to drop out of the community and other types of plants will fill the gaps.

This is what is known as community dynamics and it is one of the most powerful forces of nature. This process can work to advance complexity in the community or it can cause a change to the negative and lead to a more simplified community. Many agricultural communities exhibit symptoms of this simplification, which leads to communities with less resilience. Ecosystems have the capacity to self organise and self repair if we allow that to happen. Our modern approach is mostly to intervene with technology which can have unintended consequences.

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12. David, you said that managing the farm to increase the biota has been good for business. I recall that you said that input costs decreased, for example, eliminating the need to bring in feeds during drought. Are there are ways that it has been (measurably or otherwise) good for business?

Our business has become much lower cost. We have not spent anything on inorganic fertilisers or chemicals now for fifteen years. The level of stress from a human perspective is much lower. We feel much more able to navigate through difficult times now due to the tools we have at our disposal for calculating feed ahead of us and knowing that our management is allowing increasing diversity over time.

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13. Have you completed comparative soil tests to determine mineral changes?

No, although if you look at the chart on the last slide it shows that when there is no disturbance of grazing the soil community goes very quiet. The nitrogen levels in the pasture are double what is in the trees, but the big difference is in the phosphorus levels which I attribute to fungi unlocking phosphorus from the soil bank.

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14. What decision making tools does David use in adjusting stocking rate to match rate to feed on hand?

To work out how many days of grazing are on the farm at any time this is the process we use:

  • Go out to each paddock and step out a square that you judge would feed a 45kg wether (a dry sheep equivalent or dse), for a day. Just for this example lets assume we judge that 10 sq metres will feed a sheep for a day. There are 10,000sq metres in a ha so for each paddock that is the same as this one, each ha can feed 1000 sheep for a day. If there are 500 ha available, each of which can feed 1000 sheep for a day, theoretically you could feed 500,000 sheep on that 500 hectares for one day. But let's say you have 5000 sheep of 45 kgs. In our example, assume we have 50 paddocks of 10 hectares. To achieve a recovery period of 100 days, each paddock would need to be grazed for 2 days. A 3 day graze would give a 150 day recovery. A 1 day graze would give a 50 day recovery. The decision to graze a paddock for 1 or 3 days is dictated by the rate of growth (recovery), of the slowest growing perennial grass species:
    - Slow growth = slower moves
    - Fast growth = quicker moves
    Always monitor in front, to make sure plants are fully recovered; and behind, to check if paddocks are losing cover, an indicator you may be overstocked. Where we live in the south west slopes of NSW in the growing season recovery can be as fast as 30 to 50 days in October /November, and as slow as 90 to 150 days or even more in the dead of winter if it is dry like this year.
  • During the growing season we have an open plan (open because we do not know when the season will draw to a close and growth will stop), that plans how many days recovery the plants we are grazing will need to fully recover before being ready to graze again. The recovery period is what dictates how long stock stay in each paddock.
  • We make sure we do not overgraze. Overgrazing in the holistic sense is when a perennial grass is grazed, re grows and is grazed again, without sufficient time to properly recover. When this happens in a perennial community, the energy the plant stores to initiate new growth after defoliation or for initial growth in a new season, is diminished and if it keeps happening the perennials will gradually fade into the background and the plant community will gradually be dominated by annuals. This is an indication that management is driving succession backwards. Of course the classic example of this is when set stocking occurs, when all plants will be overgrazed all the time.

When we started managing using the decision making framework of holistic management, we found our mind switched onto the plant community rather than the livestock. How we manage the landscape is what dictates the fortunes of our business but the plants are the 'primary producers' as they are the photo synthesizers which are the energy circuit that powers all life. The natural tendency of evolution over 3.5 billion years of life has been to elaborate and diversify the biota, so why not let it do just that?

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15. How [did you] get rid of Patterson's Curse?

Under the conventional model of agriculture we often intervened with herbicides to try and control 'weed' species such as Patterson's Curse, thistles etc. That approach gives a short term fix but only addresses the symptom (weeds), of the underlying problem.

The underlying problem is that management has created conditions favourable for tap rooted forbs. The community of plants that will grow in these conditions are what we call early successional communities. These are characterised by tap rooted forbs and annual grasses.

We now try to manage in such a way that the natural process of succession from communities dominated by annuals to more complex communities that are dominated by perennials and increasing diversity, gradually develop.

We tend to look at incursions of weeds as indicators of our management being at fault.

Maintaining 100% cover of plant material, living or dead is a good first step. When we first began planned grazing we had former crop paddocks that became quite weedy, but we trusted the process of succession and chose not to intervene but to manage for the conditions we wanted, that is to manage in a way that would let succession take its course. Those formerly weed dominated paddocks are now carrying many more grasses and perennial species than before. The 'weeds' are still present but they have generally faded into the background.

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16. Great presentation from David Marsh - is there any case studies from WA with similar works on regeneration of typically cleared and grazed landscapes. Also looking at cropping/grazing enterprises, or places to look for this information.

In the first instance you can read Ian and Dianne Haggerty’s case study. With properties in the WA Central Wheatbelt, Ian and Dianne have built up a successful production area of 8000 hectares producing cereals and sheep on limited rainfall and sandy salt-affected soils. Fundamental to their success has been the introduction of biological fertilisers and a focus on improving soil function and structure.

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Colin Seis

COLIN SEIS

Grazier and cropper on the property Winona, near Gulgong in NSW. Colin is the developer and leader in ‘Pasture Cropping’.


DOWNLOAD WEBINAR PRESENTATION (4MB)


17. Could you please talk about some of the barriers you've heard about/encountered to introducing this method on any property?

The main barrier is people saying 'it will not work on my property', things like not understanding that crops should be sown into a niche when the existing grass species are dormant. Inputs like fertiliser, herbicides and pesticides should be reduced gradually over time as soil and grassland improves. The technique will work almost any where there is a dormant period, this could be Summer crops or Winter crops.

18. Is there any experience of using these techniques on other soil types, especially poor/light soils, or on steeper, rockier soils?

‘Pasture cropping’ will work in any soil type or terrain where a crop can be sown.

19. Did native grasses result from planting seeds or natural regeneration?

The native perennial grass species comes from natural regeneration from seed in the soil. The plants germinate along the drill rows. Native and/or introduced grass species have been shown to germinate if there is seed in the soil, the seed can be in the soil for many years.

20. How long did it take to benefit from the changes you made?

Perennial grass recruitment usually happens in the first year after ‘pasture cropping’. Soil health benefits like improvement in soil structure can also show improvement in the first year but soil carbon increases show a lag time and usually increase after 3-5 years as the pasture/grassland and soil structure improves.

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21. Has the carbon on Col's farm been speciated? eg labile and so-on

Yes - the increase in carbon has been shown to be 78% in humic form and 22% labile.

22. What is the market for native grass seed? Who buys it?

Most of the native grass seed is used for mine rehabilitation and some sown as pasture by land owners.

23. Have you also encouraged bushland regeneration and is this needed to support pasture cropping?

‘Pasture Cropping’ is used to restore grasslands as well as grow crops and improve soil. All of that has happened on Winona. I have also restored the bushland areas on Winona which contribute to the overall farm ecosystem.

24. Sounds good but if you haven't had animals then you'd need to put in a lot of infrastructure. Please comment.

I believe that animals should have never been taken out of cropping programs. Well-managed animals provide an important function of cycling nutrients, adding nutrients and helping to improve soil carbon. Replacing fences to run animals would need to be evaluated economically and costed carefully before doing.

25. Have there been any testing of the VAM levels in the soil in the pasture cropping system?

There have been soil food web tests and Sydney University tests. The results are:
- 862% increase in total fungi
- 1000% increase in total nematode
- 640% increase in protozoa
- 350% increase in bacteria

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26. A question for Col, what are the sound ecological principles he employs on his property?

Our properties should function as ecosystems. The better way of doing this is to restore the property to grassland or at least a pasture that functions as grassland. ‘Pasture Cropping’ and good grazing management practices that encourage this to happen will start the farm functioning as an ecosystem.

27. What starter fertiliser was used in the cropping system and what is being used now at sowing?

When I started ‘pasture cropping’ nearly 20 years ago I was using DAP at 100kg/ha (recommended rates). I reduced that to 30- 40 kg/ha gradually over 10 years as soil health improved and soil nutrients increased. Now I am using trace elements and organic/ biological fertilisers. I found that it is important not to reduce fertilisers until the soil improves (especially if growing grain).

28. My question is to Colin: did you monitor soil water status at different depths and did you also observe any changes in soil erosion compared to neighbour’s soils?

There is zero soil erosion on Winona now. There used to be when I was farming conventionally. CSIRO has measured soil water use efficiency on Winona and has shown improved WUE.

29. A question to Col and Shane: great stories, and seem like a no brainer to switch to less inputs. So why not more people follow your practices? What is the barrier for adoption? (is it lack of information, scepticism, etc)

Scepticism and advice to keep putting on inputs are some of the barriers to adoption. The fear of lower yields and being told that you may get lower yields.

The facts are: Many people when starting ‘pasture cropping’ can get a reduction in yield of about 15%. As soil health and associated nutrient cycling improves yield can be close to conventional zero till when the correct ‘pasture cropping' techniques are used.

When extra grazing and decrease in costs are factored most ‘pasture croppers’ are more profitable. There are over 2500 farmers in Australia using ‘pasture cropping’ and increasing numbers in other countries.

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30. Are you using herbicides / pesticides with your cropping programs?

I used to use herbicides and pesticides. Now I use no fungicide or insecticide (for 10 years). Most of the crops I sow have no herbicide applied, but at times I may use a very selective herbicide if necessary.

'Pasture Cropping’ should use basic agronomy principles of growing a crop. If good grain yields are to be achieved, weeds may need to be controlled and nutrients supplied to the crop. This is usually done using conventional methods when first starting, but as grassland/pastures, groundcover and soil improve we have less invasive annual weeds on our properties (less herbicide). More nutrients and water become available with improvements in soil microbial health, improved soil structure, and increased soil carbon levels (less fertiliser).

31. Are there different responses on different soil types? Has there been soil mapping on the properties?

In relation to perennial plant recruitment, soil type makes no difference if there is seed already in the soil. We see carbon increases and soil health benefits on all soil types. Of course different yield will be achieved on different soil types. Winona has been soil mapped but I find it unnecessary in pasture cropping programs except when trying to achieve maximum grain yield.

32. Does Col have an itinerary for workshops re pasture cropping?

Upcoming: Pasture cropping / soil health Workshop Merriwa NSW 5th June
Pasture cropping/grazing management Echuca VIC 12th June

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Shane Joyce

SHANE JOYCE

Grazier from Dukes Plain on the Brigalow Belt outside of Theodore in Central Queensland. Shane is successfully managing his grazing and regenerating vegetation to improve soil health and deliver increased productivity.


DOWNLOAD WEBINAR PRESENTATION (2MB) DOWNLOAD SPEAKER NOTES


33. What are the most efficient and effective ways to improve the microbial health of soils?

Good question! My first choice now days is Biodynamic Soil Activator. There are many ways to improve soil microbial health. My view is that we may all choose different methods depending on our situation, temperament, resources. So now I will try to outline what I see as “must do” components for any system:
- Ground cover. Strive for 100% ground cover
- Strive to always have green and growing plants. The root exudates (from the photosynthesis process) feeds soil biology, which in turn brings nutrients to plants.
- Do whatever you can to support the soil fungal network. It is the fungal network that usually is first “killed off” by our agricultural practices. The fungal network is like (my picture of it) the power, phone, water, internet grid that we as humans have come so dependent on. Having trees in your landscape is a good start, dead wood on the ground, cold ferments made from aloe vera or casuarina needles are my pick for spray based soil amendments.
- In a grazing system 60 days rest at start of growing season (health & diversity of perennial pastures and greater root depth).
- Animal density (large mobs on small areas for short time) promotes more even utilisation, mulching of what is not eaten, and subsequently with rest we get greater plant growth (photosynthesis) to feed soil biology.
- Whether you choose compost teas, biodynamics, or other soil amendments becomes your call. Personally our management is a combination of lots of the above and we have chosen biodynamics as we can make all our own products from on farm resources (reduces input costs/cost of production? ).
- In a cropping situation it is always good to at some stage use live animals. Live animals carry an absolute truckload of microbes and spread them via their dung and urine.

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34. What sort of pasture species have been able to grow under the brigalow? Are these natives or improved pastures?

Pasture species that grow under brigalow are both introduced and native. One of the natives that does particularly well and is highly palatable is Brigalow grass (Paspalidium caespitosum). Curly Mitchell (Astrebla lappacea) has colonised under brigalow/bauhinia clumps on our cracking black soil downs country. Of the introduced we have both buffel (Cenchrus ciliaris) and green panic (Panicum maximum). In some areas the buffel dies out after a period of time and is generally replaced by green panic or native species.

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35. For Shane - does the pasture on the cleared brigalow country dry off later than on the uncleared country?

As a general rule we are finding that grass remains greener for longer under trees. One area where we have strip blade ploughed seems to be an exception to this rule (it is a heavy brigalow clay soil). Here green panic under trees appears to go into moisture stress relatively early. Here the clear strips are around 10 metres wide. Plant spacing in the clear strips (predominantly buffel grass) is quite wide. I have not solved the riddle of this anomaly…Is it soil type? Is it a result of the blade ploughing? Overall it appears that the lighter the soils then the more benefit there is from trees and the more pronounced the earlier drying off of pasture in the cleared areas.

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36. How has weed management evolved with the changes in land management.

Weed management for us here is zero and has been that way always. The greater soil and pasture health then the less weed we get. Weeds are simply “indicators”. Weeds bring in elements that are “missing” in the system. In a degraded landscape you will often see prickly plants; these prickly plants are strong silicon accumulators, silicon is one of the first elements that are leached out with heavy rain/soil degradation. Weed scan be better managed by making cold ferments with the “weeds” that are “problems” and spraying this cold ferment (1: 10 ratio with water) back on the land. This actually “magnifies” what the weed is trying to do to “heal” the soil.

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37. Shane - can you provide some more details on 'biodynamic preparations'? (Multiple questions on this.)

The biodynamic preparations. Biodynamic Agriculture Australia (biodynamics.net.au) is a good resource base for information on Biodynamics. Briefly though there are a number of “preparations” which come from 1924 lectures done by Rudolph Steiner to a group of German farmers, soon after World War 1. Due to the use of chemical fertilisers these farmers noticed that all was not well with their farms. Steiner’s lectures are now known as “The Agriculture Lectures”…originally they were titled “The Spiritual Renewal of Agriculture”.

We are using mostly what we call Soil Activator, a combination of Horn Manure (fresh cow dung buried over winter in a cow horn), Horn silica (finely ground silica buried over summer in a cow horn), Cow Pat Pit (cow dung, eggshells, basalt dust with 6 compost preparations ) CPP is made all year and takes around 4 months to brew. A wheel barrow load of this will treat 1000 acres!!! Also in this I add elements that are “lacking” in our environment (boron, casuarina ferment, aloe vera ferment, sea weed, diotomaceous earth). Also horn clay (clay buried in cow horn). Are you now feeling confused?? This is one of the “issues” I found when working with new farmers/gardeners…if I trotted out all these individual preparations and recipes they soon were confused and glazed over…this led me to making soil activator (one product, no need to explain what is in it, mix with water and spray it out).

A good resource to start with is Biodynamic Agriculture Australia’s “Resource Manual” and a book “Grasp the Nettle” by Peter Proctor. Both are available on line through biodynamics.net.au. The compost preparations are made from stinging nettle, chamomile flowers, valerian flowers, dandelion flowers, yarrow flowers, and oak bark. These are also buried in various animal organs. The compost preparations “activate” processes in the soil and are used for decomposition and digestion. Yarrow activates K, Si, Se, and S. Chamomile activates N, Ca, Manganese, and B. Nettle activates Fe, K, Ca, S, and Magnesium. Oak Bark activates Ca, and P. Dandelion activates K, Si, Magnesium, B, and Se. Valerian activates P, Se, and Magnesium.

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38. What type of systems are you using to measure the improvements?

We measure using our grazing charts. These are a record of cattle numbers, what paddock they are in, for how long, rainfall, rest periods, available pasture. I use my pocket knife and a shovel to do soil samples (smell and feel), and check depth of rainfall infiltration. We do some soil sampling (EAL in Lismore) and look at available nutrients, total nutrients, organic matter levels. Along with this we do tissue sampling to see what nutrients the plants are taking up. 3 soil sampling events in 30 years! Observation, observation, observation…I often abandon the quad bike and simply walk and sit in the paddock to get a “feel” for what is going on. We also have 10 fixed point photo sites where we take the same pics at end of March (end growing season) and start of October (end dry season).

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39. Was there a side-by-side controlled comparison done for the biodynamic preps?

Absolutely no. My temperament type does not do this sort of thing!! When I do something I go in “boots and all”, having an absolute “belief” or faith that it will work. We do use the road sides as a bench mark (not the neighbours paddock). Ecological health seems to just keep on trucking on the road lanes Australia wide and the plants (grasses) we want in our paddocks grow there unmanaged, with no technology, and no money inputs. We are trying to get happening on farm what is happening on the road side, and making it happen even better (closer plant spacings). I do soil samples when I start in paddocks and monitor progress at future sprayings.

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40. A question to Col and Shane: great stories, and seem like a no brainer to switch to less inputs. So why not more people follow your practices?

Change is a scary thing. Often as humans we are more comfortable doing something that we know is not working well, however there is safety in knowing intimately what we are doing.

What is the barrier for adoption? (is it lack of information, scepticism, etc)

Briefly there are two streams of science; Newtonian which is characterised by fear, doubt, and scepticism. Then there’s Goethean science which is characterised by courage, confidence, and enthusiasm. We are educated in the Newtonian stream, so being a Goethean does not come easily. In this question you have really hit the nail on the head... we fear change, we are sceptical about new things, and we need more information. As a Goethean scientist one gets ones information from our main instrument of science, which is our body (feel, smell your soils, intuition). As Newtonians we want someone else to be the expert who does scientific studies, the agronomist who advises us how to manage our soils, crops, animals, or the guy in the produce store who sells us some more stuff to put on our farms. Neither stream of science is right or wrong, we just need to get a balance between them. As land managers we also suffer from “frog in saucepan” syndrome…that is put a frog in cold water in a saucepan and bring to boil... he stays there. Toss a frog into boiling water and he will do his best to get out! Yep sadly often we need to be in real crisis before we adopt change, then often it may be too late!

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41. Question for Shane. Do you use fire at all to support your farm management?

Love questions on fire! Yes we do use fire - How is the important part. Let’s do some background on this issue. Pre European (read The Biggest Estate On Earth by Bill Gammage) the aboriginals managed the landscape with fire, however there were no large herbivores to eat the pastures. Now we have large and small herbivores (sheep, cattle). The generations that came before me in our landscape managed also using fire, however there was a grazing animal there to graze the grass as it began to re-grow. Still land managers in our area do this and it has resulted in a reduction of the palatable, productive, perennial (good) species in our pastures. There has been a subsequent increase in unpalatable, unproductive, annual and weed species. Along with this “poorly managed” fire and grazing regime, we have got a corresponding decline in soil structure and fertility. Also our rainfall is leaving via surface runoff (causing big floods) and our rivers, creeks, and underground waters are drying up. How then do we use fire “productively”?

Most our fires here are wild fires started from lightning strikes, from road side camp fires, sparks from passing traffic. We have our sandstone escarpment country which we “sacrifice” to these fires and some of our grazing land also in west of the fire break that surround the escarpment country. We burn back from this break to protect the majority of our grazing land. Once (when) these areas are burned we rest them for a full growing season (summer) to allow for the re-generation of the 3 P grasses (palatable, perennial, productive). This management has proven very successful and by using fire in this manner we can “shift” the state of a pasture/grass community. The undesirable grasses then start to reduce in the pasture. So fire is a tool we will not totally give up, however the use of fire and the results are dependent on the ‘after’ management. We have also burned catchments to dams to get more runoff to fill dams (once unsuccessfully!) I like to speak of having a fire driven environment (aboriginal Australia) or a ‘browse driven environment’. Africa has a browse driven environment. We are striving to “change” our property to a more browse driven environment.

The only people who make money from smoke is the tobacco companies!!! I prefer to “burn” grass in a cows rumen as we can make money that way!!!

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42. Where do you get the cow horns for the biodynamic preparation?

We get horns from a number of sources…Biodynamic Agriculture Australia…from meat works…from other cattle producers…we do not use cow horns exclusively, we also use steer and bull horns! As well I have used ostrich eggs!!!

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43. Are there different responses on different soil types? Has there been soil mapping on the properties?

Yes different soils act differently. Sands are by nature very fast to change. Clays by their nature are very slow to change. Lets look at the why (my view) of different soils. If we look at the Cooloola sand mass and Fraser Island rain forests on pure white sand. The sand has zero capacity to hold fertility/nutrients/water - cleared it becomes like the beach! All the nutrients are tied up in the vegetation and cycles through the veg very rapidly - high rate of biological breakdown, high growth rates. Heavy clays on the other hand “hold” onto fertility/nutrients/water where the challenge is to get these soils to “give” some of their resources up for the growing of plants. To have a good mix of soils on farm is a real asset (diversity). Our soil mapping is very basic, and soil types do influence how we manage different areas. In brief I would like to see our sands respond slower and for a longer period, while in our clays I would like to see them respond faster and for longer.

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44. How would you regenerate clay soils/heavy clay soils in semi-arid climate?

Biodynamic preparations, grazing management, increase plant density, increase perennials, grow trees and shrubs, maintain a good litter cover at all times, have plants “ready to grow” at all times, use animals (a round bale of hay and a big mob of cattle on clay pans works well), rest - adequate rest for plants to recover from grazing events.

[Soils for Life: Read the Bokhara Plains case study to read how claypan has been regenerated.]

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45. Gypsum is used in periurban areas for breaking down clay soils - is gypsum not appropriate to the rural setting?

The use of gypsum is alright, however in many areas the levels of production do not allow for the cost of many of these types of input. Production and production capability of land comes in here along with cost of production. An extreme of this is in my days in Permaculture - Mollison wrote of a case in America where they were actually using 10 eggs worth of energy (inputs) to produce 1 egg to go on your table (output). So yes, inputs/outputs has to be where it is an economic proposition.

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46. There was a great study done recently in the Swann Catchment area south of Perth on science and benefit of Biodynamics. Very good data?

Can I (we all) get access to this information please.

[Soils for Life: We'll attempt to track it down and include it here.]

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Tim Wright

TIM WRIGHT

Grazier from Lana, near Uralla in NSW. Tim's monitoring of rainfall and stocking rates provides evidence of how his holistic practices have supported an increased carrying capacity regardless of rainfall.


DOWNLOAD WEBINAR PRESENTATION (3MB)


47. Does Tim use any software packages to manage pastures, paddocks, grazing and stock rotation?

Transcribed from Webinar:
I don’t have a software package to suit what I do, but what I do, is match the stocking rate to the carrying capacity every season. So I sit down and look at the total DSE rating (I’m answering this in terms of monitoring what we’re doing in terms of stocking rate and carrying capacity), so each farmlet I look at the numbers I look at the total DSE rating that we use, like 12 DSE per cow or whatever it might be, and then I look at that in terms of what we’ve done in the past, and I can chart that myself, graph it or whatever, to see trends, how we’re going with each farmlet. And it’s a simple way of charting it.

We used to do the grazing charts, which if you do an RCS course they’ll show you different ways, and they’re a great way to start it. But when you end up with over 300-odd paddocks and the number of farmlets we have you’d spend half your day doing these charts, so I had to do it a different way so that it kept it simple and kept our finger on the pulse. There is no computer software program that will do what I’m doing. I can do it without it, quite simply.

The other thing I’ll just mention, if you do a calculation on the yield, as in DSE days per hectare, you just multiply the number of DSEs by the number of days, and divide it by area and you get the DSE days per hectare and that’s a simple way of monitoring what sort of yield you’re getting out of your paddock when the stock move out and you can benchmark that against other farmlets.

48. Has the rainfall efficiency been reflected in stock quality and weight/ha and financial returns/ha?

Answer coming soon...

49. If carbon sequestration is the main game for these changes what consideration is given to the toxicity of herbicides to the beneficial micro-organisms like mycorrhizas from glyphosates? How beneficial is the use of fulvic acid in conjunction with glyphosate in protecting these essential micro-organisms from this negative effect?

Transcribed from Webinar:
Because we’re a native pasture situation, I used to do pasture cropping, and I did apply a little bit of round-up a few years ago, but they were the worst paddocks as a result, it took a few years for that to recover, even from a small amount, so I’m very anti-herbicide in that sense. I think we need to start looking outside the square a bit and start thinking how can we do, get control of weeds and things by using animals. I think Col Seis has proved that with what he does, by using a big mob of wethers. There’s room for using livestock, with different ways of fencing, virtual fencing, electric fending, new ways are out there coming on the scene; I think they’ll have a big impact. We might see a reduction in herbicides.

50. Did you actually "grow" soil or was it the bulk density of the soil reducing. What was the base reference point (depth) to determine the "growth of soil"?

Transcribed from Webinar:
We’re doing exactly the same as Bill and Rhonda, but I’m doing it [“growing soil”] via a natural composting way, in terms of high density stocking laying down manure and resting and building all the time. …Starting from a soil that doesn’t have topsoils, in those poor granite soils – you’re lucky to have half a centimetre of what I call dark humus colour. But we should be a couple of centimetres now deep, which is big, in terms of organic matter we might be 2 or 3 percent, but now we’re 6 or 7 percent organic matter over that time period. It doesn’t happen over night, but you can build soil. It’s a simple way of doing it… In terms of what we’re doing and the scale that we’re operating on, and in economic terms, I found that by doing it by the animal through a stock density is a fairly economical way of doing it, and it’s ongoing. The beauty of it is, as the stock move out, you’re building that soil, so by the next time the stock come around, that soil is better again. Every time the stock go into the paddock should be getting better, not worse.

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Bill & Rhonda Daly

BILL & RHONDA DALY

Grazing and cropping on the property Milgadara, near Young in NSW. Measurement and monitoring have been key to the Daly's understanding of their landscape, enabling them to balance soil structural, biological and mineral components.


DOWNLOAD WEBINAR PRESENTATION (6MB)


51. Where do you obtain the input biomass to create your compost / tea / humus builder? Does this source and quality vary seasonally or annually?

Transcribed from Webinar:
In the composting we have a recipe, a bit like a cake. As long as you get a 25:31 carbon to nitrogen ratio and you have the porosity right. There’s over 300 feedstocks, so yes, they can vary, but we have 44 composting operations around Australia, so everyone is using different feedstocks in their operations...

Mainly where we got them from in the beginning, we were cutting our stubbles off, our soils were very dead and the stubbles weren’t becoming beneficial; breaking down into humus, so we were removing stubble, we were putting in manures and clay, clay is a foundation of the humus structure, so we always add clay. But now that our systems are really working and living again, we’re not using our stubbles, we’re getting a lot of people who bring us their stubbles, or hay, straw, and we compost it for them and give that back to them.

In a wet spring, it was not good for the farmers, but it was good for us, because they had a lot of ruined hay that they were making, we could buy that. We have a lot of intensive piggeries and dairies, and chickens at Young, so we can gain those, also from abattoir waste. There’s a lot of feedstocks that people can source, if you’ve got green waste in your local council if you’ve got cardboard, if you’ve got paper, all of those sorts of things are able to be composted.

52. What changes in organic carbon have you measured using soil tests?

Between 2007 and 2009, we increased organic carbon by .26% in the top 15 cm of soil, this represents a 6 tonnes a hectare increase in soil organic carbon which equates to 22 t/ha of CO2 sequestered.

53. Did you actually "grow" soil or was it the bulk density of the soil reducing. Or what was the base reference point (depth) to determine the "growth of soil"?

When I refer to growing soil I mean refer to two different methods of assessing it. The first is the physical depth of humus (organic matter (om) layer) that is visible when a profile of the soil is dug up and secondly the amount the cation exchange capacity (CEC) has changed (improved) eg. from 4 to 7.

54. More on the composting - are the inputs organically grown or from fertilised crops?

The inputs can be from both, some inputs are organically grown and some from fertilised crop. For the production of an organic standard Humus Compost the feedstocks do not have to be organically grown, this is due to the fact that the 10 week Advanced Composting Cycle breaks everything done microbially and thermophilically into its smallest part and then the Humifier (microbes) build it into humus.

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55. Are you not transferring nutrients from one landscape to another by bringing in nutrients- no issue with using them but what about the big picture?

As you probably know we run the business YLAD Living Soils so all the compost we produce is not used on our farm. Most of the feedstocks utilised if not composted would contribute to a release of nitrous oxide or carbon dioxide. All feedstock are sourced within 40 kms of the composting site, we believe that by producing a local fertiliser from local feedstocks for the production of local food is very sustainable. The importation of MAP, Urea etc from overseas is very questionable in the long term for food production.

56. If carbon sequestration is the main game for these changes what consideration is given to the toxicity of herbicides to the beneficial micro-organisms like mycorrhizas from glyphosates? How beneficial is the use of fulvic acid in conjunction with glyphosate in protecting these essential micro-organisms from this negative effect?

A good question as we all are aware of the detrimental effects of all chemicals on soil microbes. Building soil carbon, thence carbon sequestration, is of course a priority. As biological farming is a systems approach every consideration is given to the thoughtful use of chemicals. As the soil becomes healthier and more balanced the need for chemical application reduces, as the soil has a greater buffering capacity to these nasties. There is evidence that using fulvic acid in conjunction with gylphosate reduces the detrimental effect to the single celled algae which are the photosynthesises in the system. Supplying fulvic acid also provides a food source for the microbes. Another product Agri-Organica can be added to any chemical to reduce the harmful effects to microbes. Trials performed overseas show very good results.

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57. Has anyone heard of the process of injecting tractor exhaust emissions back into the soil as a means of sequestering carbon / reducing emissions - I would think it may be deleterious to soil organisms?

Ian and Jodie James in WA have been at the forefront of this technology utilising the tractor exhaust emissions very successfully. I am not an expert in this area so will not comment.

58. Do Bill and Rhonda consider the effect of importing nutrients in compost feed stock in their overall nutrient budget?

Once again all the compost is not used on Milgadara as we run a commercial biological fertiliser business and Humus Compost is one of the products we sell. If you are referring to the amount of N used to produce the crop, i.e. canola and wheat as in the presentation, then we are merely referring to the amount of soluble synthetic nitrogen that was used to give a comparison to conventional.