Thursday, May 27, 2010

Livestock and Soil Compaction Quantified for Tropical Regions

Most agronomists would have been aware of earlier NZ studies on the influence of livestock on soil compaction and subsequent reductions in pasture or crop yields. New Zealand conditions are wet, and soils are quite different to northern Australia.

Yet, there is this perception that livestock cause severe soil compaction. More recent Australian studies would appear to refute these earlier claims, at least for our own conditions.

The following material was in the GRDC Magazine Ground Cover, no 86 in May 2010, and reproduced with permission.
Livestock compaction quantified

The compaction effects livestock have on soil may not be as problematic as previously thought, a Queensland-based research project is finding Livestock compaction may be less of a problem than many producers think, research by CSIRO’s Dr Lindsay Bell, who leads a GRDC-supported Southern Queensland Farming Systems (SQFS) project*, has found.

By examining numerous existing studies Dr Bell found:
• stock apply similar pressures on the soil to unloaded vehicles;
• treading by livestock can reduce soil porosity and infiltration rate, and increase soil bulk density and soil strength, although these consequences are mainly in the soil surface (the top five to 10 centimetres);
• despite these effects, reductions in crop performance have rarely been measured, possibly because effects are too small in magnitude or depth to influence plant growth significantly;
• crop simulations with reduced root growth and surface conductivity suggest that even in the most severe case a 10 to 15 per cent reduction in yield on average could occur;
• the risk of compaction can be reduced by removing stock during wet conditions and maintaining soil organic matter; and
• because compaction from livestock is shallow it is not long-lasting and is rectified by natural processes or tillage.

For example, one study Dr Bell looked at was Bruce Radford’s (Department of Environment and Resource Management, Biloela) two-year study on grey vertosol soils in Central Queensland.

It found that when cattle grazed sorghum stubble when the soil surface was dry there was no impact on subsequent crop growth or grain yield. But grain yield was reduced by 15 per cent when cattle grazed stubble when the soil was wet.

Similarly, a Western Australian study found there was no effect on grain yield from grazing a pasture the previous year. However, reduced wheat plant density did occur when sown no-till into areas that were continuously grazed the previous year.

As well as examining numerous studies, Dr Bell also undertook a modelling study using APSIM (Agricultural Production Systems Simulator) to investigate how sensitive simulated wheat yield is to livestock’s surface compaction effects. The study was modelled over a 50-year period (1956 to 2006) and explored the two main effects – reduced root growth and reduced surface water conductivity – independently and when combined. The model did not account for the possible effects of diseases or waterlogging.

Averaged over half a century, the results showed that mild surface soil compaction from livestock would result in reductions in grain yield of less than 10 per cent. These mild compaction effects are similar to most documented changes in soil conditions after treading by livestock, implying that in most cases the effects of compaction by livestock on crop performance are small. This is supported by the few studies that have investigated this experimentally, Dr Bell says.

Crop losses could be higher if more severe soil compaction occurred, especially if surface infiltration was greatly reduced and ground cover levels were low. Yield losses in the severe scenarios averaged 10 to 15 per cent, but might be as high as 30 per cent compared to the control paddock. However, these severe reductions in root growth and surface infiltration that were modelled are far more severe than most observed effects in the field.

The modelling also found that reductions in crop growth and yield were more affected by lower surface conductivity and rainfall infiltration rate rather than by reduced root growth in the surface layers. Hence, maintaining surface conditions such as stubble cover, which improves infiltration, decreased these effects.

Although this study used computer models to explore livestock compaction effects, there is a need for more experimental data to investigate how crops respond to changes in soil surface condition from livestock grazing.

* Dr Lindsay Bell leads the SQFS project ‘Short-term pastures in grain systems’.

Common sense says avoid too many stock on areas that are very wet and boggy.........but that effects are generally modest, and may not last too long. Interestingly, adequate soil organic matter mitigated compaction problems.

Wednesday, May 26, 2010

Agriculture WILL be Part of Biofuels Future

While there have been many naysayers about the role of crops in biofuel production, recent developments do show a somewhat different pattern emerging as new generation production facilities are coming on line.

In 2007, the US Department of Agriculture estimated cellulosic ethanol production costs at $2.65/gal., compared to $1.65 for corn-based ethanol.

POET recently reported that it lowered production costs for cellulosic ethanol - including capital expenses - from $4.13 to $2.35/gal. in one year, as of November 2009, at its South Dakota pilot plant and hopes to lower it further.

Novozymes, the leading producer of enzymes in the world, recently estimated that the cost of enzymes for cellulosic ethanol production [ in the USA] has been reduced significantly in the last two years to about 50 cents/gal., reducing total production costs in the near term to about $2/gal.

Algae has great yield potential, but production cost estimates (net of capital costs) for growing and converting algae to fuel are significantly higher, ranging from $9 to $35/gal. depending on the production technology, the report notes. "Developing the capacity to use multiple feedstocks and to produce bio-based fuels that are equivalent to fossil fuels that can be used in current vehicles without limit and distributed seamlessly in the existing transportation sector may become the least-risky business model to pursue," the report concludes.

Read the full report at

Some new plants are producing biodiesel from waste fats, rather than new farm based oils or similar eg palm oils.

Work continues in a range of countries, with biodiesel small scale plants making some inroads in developing countries.

Australia still seems to be locked into ethanol from sugarcane and grains..........yet the new cellulosic ethanol option would seem to be of increasing importance.

Will we see Australian grassy weeds - with lots of biomass for example gamba grass - be seen as valuable for cellulosic ethanol production. Many sure do produce a lot of biomass!!

There is also a good article here:

Wednesday, May 19, 2010

Could Roundup Ready GM Crops Induce Nutrient Deficiency?

The answer appears to be yes, but only due to the mode of action of the glyphosate. Longer term, overuse of glyphosate or continual regular use without other products use, may lead to mineral tie up in soils...........and nutrient deficiency. No doubt, this can be adjusted, with additional fertilisers.

But the real issue is, as Monsanto has proclaimd loud and strong for almost not continually use glyphosate. There are issues of weed resistance, as well as potential nutritition issues. Trouble is.........some, possibly many, users are either not listening, or ignorant of the potential problems.

This does not necessarily imply using GM crops is bad. One needs to make informed choices, as already stated in a previous post.

Glyphosate is a very good and very useful chemical, probably the most successful product in this group - ever. Its ongoing efficacy requires users to use it properly.

The following article cover this issue in more depth.


Glyphosate is to weed control what penicillin was to disease control in humans when it was first introduced. But as over-reliance on penicillin led (inevitably, as we now know) to resistance in disease organisms, so over-reliance on glyphosate has led not only to resistance in several weed species, but also to the gradual lessening of nutrient availability to plants.

Both trends have worrying implications for crop production worldwide.

Glyphosate resistance in weeds

Professor Stephen Powles, of the University of Western Australia, has identified glyphosate resistance in nearly a dozen species of weeds in North and South America (Powles 2008). Where only 14 years ago farmers began growing Roundup Ready crops, including maize, soybeans, cotton and Canola, which survive the direct application of glyphosate while everything else succumbs, the continued use of glyphosate alone – in direct contravention of Monsanto’s advice to rotate herbicides – has seen the emergence of herbicide-resistant weeds that mean crop failure. Powles attributes this sudden rise in weed resistance to the sole use of glyphosate on every crop by farmers eager to maximise their profits. This short-term gain comes at the cost of long-term viability.

Unlike in the USA, farmers in Canada regularly rotate their herbicides with their crops. The result is that glyphosate resistance is unknown in Canada (Holmes 2010). Powles emphasises that rotation is the only way to secure the continued viability of glyphosate.

Hidden nutrient deficiencies

A more insidious trend, although just as worrying, is the emergence of evidence that continued use of glyphosate can reduce the availability of nutrients in the soil, and that regular use on Roundup Ready crops can interfere with nutrient use by plants. Dr Don Huber, professor emeritus at Purdue University, USA, reports (Huber 2010b) that because glyphosate acts by chelating (tying up) certain metal ions, which are essential in plant enzymes, not only does it kill susceptible plants (by stopping the enzymes from working), but it also ties them up in soil.

He states that contrary to popular belief, glyphosate does not break down in soil (nevertheless, see the references in an earlier article that describe the breakdown of glyphosate by microorganisms), and that it can continue to tie up metal ions (some of which, such as Mn, Cu, Fe, Mg and Zn, are essential plant nutrients) in the soil, preventing plant uptake. (Certainly glyphosate bound to soil minerals is free to tie up metal ions.) He points to evidence of a long-term decline in crop growth in trials in Germany (Huber 2000a) as a result of glyphosate build-up in soil.

In addition to its effects in soil and susceptible weeds, glyphosate ties up metal ions within Roundup Ready plants as well. The resistance gene in Roundup Ready crops does not degrade the glyphosate in the plant; it simply bypasses its effects. So every time a Roundup Ready plant is sprayed with glyphosate, the plant takes up that glyphosate, which then adds to the store of locked-up nutrients in the plant. This effect explains the brief yellowing of resistant plants after an application.

The net result is a reduction in crop yields, both within the growing season and over several years. (Research cited by Wikipedia showed that crop yields were reduced by 6.7%.)

What you can do

If you suspect the emergence of resistant weeds, your best course of action is to switch herbicides for a year. Speak to your local district agronomist or district horticulturist for advice on suitable chemicals. Or use "double knock" techniques. There is additional material available from the web site of the GRDC -

If you are worried about the locking up of nutrients, have your soil and plants tested. There are tests for the presence of glyphosate residues in both. If nutrient availability is low, we can advise you of how much of which nutrients to apply.

Further reading

Holmes R. 2010. Weed resistance could mean herbicide is futile. New Scientist 2760 (15 May): 12.
Huber DM. 2010a.
What’s new in ag chemical and crop nutrient interactions. Fluid Journal 18(3).
Huber DM. 2010b.
Ag chemical and crop nutrient interactions – current update. Botany and Plant Pathology, Purdue University, Indiana, USA.
Powles SB. 2008.
Evolved glyphosate-resistant weeds around the world: lessons to be learnt. Pest Management Science 64(4): 360–365.
SESL. 2009.
The Loam Ranger – Glyphosate.

[latter information modified from other sources]

Tuesday, May 18, 2010

Bees ARE Dying - BUT is it Really Colony Collapse Disorder ?

No one disputes that bees die overwinter, especially in tough winter conditions. The real argument is whether the so called CCD - syndrome is really a disease or just the sum of many issues occurring.

An Australian has now added a more realistic tone to the debate. It is worth reading.


[reproduced off Qld Country Life on line]

A new unexplained disease is supposedly laying waste to honeybees in the United States, but one of the world’s leading bee pathologists, CSIRO’s Dr Denis Anderson, is yet to be convinced that it’s actually happening.

Dr Anderson is a leading expert on a tangible bee threat, the varroa mite, but the well-travelled scientist can’t buy into the story of Colony Collapse Disorder (CCD), the malaise that is supposedly behind the death of up to a third of US honeybee hives last winter. “CCD is a recently invented term for an old disorder: winter losses,” Dr Anderson suggested. "And we all know that losses over winter are due to a range of factors, from varroa to nutrition and management.”

Commercial beekeepers in the US have always accepted winter losses of 10-20 per cent, Dr Anderson said. Bees die in times of hardship, like everything else. The difference is that since the alarm was raised about bee deaths in 2006-07, and CCD was employed as a cover-all term for the issue, detailed statistics have been recorded on losses.

Dr Anderson has some issues with this.

One is that deaths from hives maintained by amateur beekeepers are being lumped in with hives kept by professionals. Amateurs tend to have higher losses because their hives are less closely managed.
Another is the question of baseline. For the last few years bee death statistics have been used as evidence for the presence of CCD—but Dr Anderson points out that prior to 2007, statistics on honeybees were less rigorously maintained, so there is no firm basis for comparison.

He is also wary of the fact that the CCD surveys in the US are being conducted by the same research agencies that are receiving funding to investigate CCD. “It’s a bit like putting a politician in charge of their own popularity polling,” he said.

His own view is that CCD is being inappropriately being applied as a single symptom to hive failures that are in reality caused by a range of different challenges. “We need to get rid of the term ‘CCD’ and deal with each event as a separate issue,” Dr Anderson said. “There are enough problems out there for bees—no need to invent another one.”

In this, Dr Anderson is in accord with bee researchers, pro-CCD or not.

US researchers investigating the CCD phenomenon acknowledge that it doesn’t appear to have a single cause, and no single cause has emerged as being more likely than another.

The United Kingdom’s National Bee Unit has investigated winter bee deaths, and concluded that the UK doesn’t have CCD but is losing bees for a range of other reasons.

Pesticides are a frequently-cited potential culprit in CCD. In Dr Anderson’s view pesticide exposure was possibly behind the intial CCD alarm raised in 2006 by a Pennsylvania apiarist.

He has met the apiarist, who again made the news in reports of 2010 bee losses, and notes that he hasn’t moved his hives from the area where the initial losses were incurred.

A US study published last month found that American bees carry a high load of pesticide and metabolite traces: 121 different chemicals were found in 900 hive samples. But the authors still warned against jumping to conclusions. “While exposure to many of these neurotoxicants elicits acute and sublethal reductions in honey bee fitness, the effects of these materials in combinations and their direct association with CCD or declining bee health remains to be determined,” they wrote.



I think the title is misleading. As the Dr Anderson says: "There are enough problems out there for bees—no need to invent another one." A better title would be: Bee "Colony Collapse a myth"? Also I doubt very much that amateurs are affecting the losses. For one thing many amateurs tend not to report losses. Most of the ones I know are doing OK and often know the reasons for losses. But bad summer/winter = high loss anywhere. Surely in question (and not really mentioned in this article) should be some of the high density, commercial migratory practices which put a massive artificial strain on bees. We take their honey and feed them corn syrup, lock them up in warehouses over winter, ship them thousands of miles, and treat them with chemicals and acids. With nature you get what you put in my view.
Posted by jon, 17/05/2010 7:36:03 PM

This is indeed a very well written article which I tend to agree with. Having spoken to a number of beekeepers myself, all of whom appear to be in agreement that this CCD is tantamount to scaremongering! None of the beekeepers are put off continuing with their hobby as all agree that to incur losses amongst their hives is to be expected. It just makes for better beekeepers the following season. However, let us not forget that our honey bees are vital for our very way of life and we do all need to be aware of this. Lets hope its the CCD theory that dies out and not them or us. Too many theories without real foundation is not what we need, more help for beekeepers who should seek it is the only real answer in my opinion. Janette from:
Posted by Janette Marshall, 18/05/2010 12:55:23 AM

Dr. Anderson is arguing semantics. He is also lumping pesticide loss, nutrition, genetics and what not... into the term "winter losses". I.e., he is commenting as if this is something "normal." It's not normal. And it is not just an issue in the USA. Pesticide usage is at an all time high. All pollinators are in steep decline, and there are serious issues with genetic diversity and other factors with honey bees. CCD is just a grouping of similar symptoms that were simply not something that was common in the past. Not this common. I have met and know some of the researchers looking into the problem. They are not being disingenuous. Sure, they may or may not be on the right trail, but they, at least the ones I know, are not being unethical. Call it "winter losses" but "winter losses" are significantly higher now. Help us, Dr. Anderson. Conclusively determine *why* winter losses are truly higher (and they are), Dr. Anderson. That would helpful. And then let's try to solve it together. Call it "MPD"? Massive Pollinator Decline? Semantics. -tawster, beekeeper
Posted by tawster, 18/05/2010 4:04:32 AM

Or just like everything else, we are shipping them out of the country. We are sending most of ours to USA.
Posted by pm in waiting, 18/05/2010 7:35:03 AM.


Loss of pollinators IS a big issue for many in agriculture. The article does raise a few notable issues for pondering though.

Monday, May 17, 2010

Rabies on the Doorstep - Indonesians Need Help

Rabies is a horrible, horrible disease.

It has now established a toehold on Bali, as well as a decent footprint in Flores. Especially from Flores and the myriad islands offshore, it is but a short hop to Timor along already existing local trade routes and then to Papua.............and across the Torres Strait to Australia.

If nothing is done to push these infections back, it will be when, NOT if according to Helen Scott-Orr, a very reputable vet, formerly working in a senior position in the NSW government.

This should be enough to develop a very major response from the people of Australia to our Government to offer significant assistance. With death and mayhem in these two islands already, we should be seriously considering how to help.

It might be impossible to eradicate rabies if it ever got to Australia.

See more here -

Saturday, May 15, 2010

GM Crops Part of the System But NOT the Only Part

Using GM crops is a decision, just like any other farming decision. What to plant and how and when, what to use in a rotation.

Farmers are now advised to mix use of glyphosate and other products especially diquat / paraquat to ensure complete annual grass controls and minimise development of glyphosate resistance. Tillage might be part of the equation too.

GM crops are not a panacea..............with decisions about use considered in relation to many factors.

The recent article in an online version of the Queensland rural press covers these issues well. It is worth reading by both pro and anti GM camps to highlight decision making processes. Most are not so blind, that they cannot see................

Friday, May 14, 2010

Energy Saving Superior Lighting is Coming - VERY SOON

Philips has announced a consumer suitable LED replacement for the 60W incandescent bulb, probably the most common type used in domestic buildings.

It is not likely to be cheap, at least initiallly,...............but it is expected to last about 20 years plus and will save an enormous amount of energy if widely used.

It is also dimmable and can be coloured so a range of lighting effects are possible.

Not available for several months still, but is the first of what could be more options in this area.

Details available here:

A day later Osram Sylvania also fessed up with a similar product. With other manufacturers also now likely to have similar products, expect the price to fall to a seriously better price......soon.

See here:

Update on 15 May 2010
And a day later Lemnis also offered an LED bulb that was cheaper and more here:

This might be a 'hot" space with multiple options now available. Prices will definitely fall!
When might we see similar products here in Australia I wonder???

Saturday, May 08, 2010

An Environmental Duty of Care?

Australian landholders are possibly going to have imposed on them an environmental duty of care, in relation to land. It is not spelt out in any real detail, nor does it imply which groups will be affected- all or some landholders, nor whether the Crown itself would be bound by such a duty of care.

The Henry Tax review seems to have strayed a little in delving into this subject. Maybe landholders can claim significantly more as a deduction for doing this work?

Given that the Crown in almost any jurisdiction cannot adequately manage NOW the land it controls this could soon descend into serious farce. If you look at weeds, feral animals, and similar problems it is usually the Crown that has the worst records of adequate management of the land it controls. Most if not all other landholders do take some measures to use suitable environmental management practices.

Would this new approach mandate using conservation tillage? Doing do would mean more soil carbon stored, but that may also interfere with adequate soil disease control and / or in some cases aid disease control. Who gets to decide on the appropriate action? And if you used the most cost effective herbicide to control weeds but which only offered 90% control versus some new patented product at 10 times the price which gave 95% control [ rarely get 100% in real conditions] are you carrying out your environmental duty of care?

This could be a lawyers picnic!

Almost all landholders exercise a fair and reasonable approach to the management of the land and imposing these extra conditions seem silly. Who will pay?

Why not use a similar approach with urban land holders? Should they be forced to compost all their organic waste and use on site to minimise use of landfill or other disposal methods? Is that part of their environmental duty of care?

As I said..............a lawyers picnic is coming if this proceeds! sounds good, but could be fraught with bureaucratic nonsense especially over any competing choices - cuddly animals or weed control might be choices that would be needed. Who wins? Who decides?

Other commentators seem to have similar issues.

See -

Friday, May 07, 2010

Salth Tolerant Durum Wheat for Australia

While some research teams have gone all high tech eg Mark Tester and team in Adelaide at the Plant Genomics Centre on the same general problem of salt tolerance in cereals, this CSIRO group has used conventional breeding approaches, with success.

Salt land is a serious problem in many lower rainfall cereal growing areas, and with durum wheat commanding higher values, getting a better yield on these areas is important.

And it does go to show that there is still a lot of life left in conventional breeding approaches to crop development!

Read more here:

Thursday, May 06, 2010

Cane Toads Confirmed as Established in Sydney

They have been moving south slowly for many years, but now seem confirmed as established in Sydney, NSW.

Recent news reports seem to have shown a small colony at a factory in south metropolitan Sydney, apparently from hitchhiker toads on containers.

It would seem to me they have not even tried to get rid of them, at least in a serious ongoing campaign. Suburban Darwin has curtailed and even removed many of the pests in suburban areas through an ongoing 'search and destroy" campaign, and it seems to have worked.

If they are restricted to a small area.............surely they can be trapped and removed. But it must be ongoing.

Read the news story here:

They are a real pest, and it is worth the effort to contain them.