No, Cows Don't Make Fertilizer

Fertilizer that comes from cows or other animals does not really originate with them.  Manure from cows and other animals has been used as a crop fertilizer for millennia, and it is still used today for about 5% of US crop acres and for a high proportion of organic acres.  It is often spoken of as an alternative to "outside inputs" for crops and as a superior option relative to "synthetic fertilizers."  However, just as Obama said about businesses and infrastructure, "you didn't build that," when it comes to fertilizers from animal sources we must also say, "they didn't make that."

Don't get me wrong, I think that cows are wonderful.  It is only because their complex, ruminant digestive system houses certain bacteria that we humans have access to the most abundant form of plant-stored solar energy - cellulose.  Animals also do a rather good job of absorbing the mineral nutrients like nitrogen, potassium and phosphorus in their feed, but they are not 100% efficient at utilizing their dietary input.  So, their manure still contains nutrients which can fertilize a crop.  But the animals didn't "make" any of those nutrients.  For instance the ~2% nitrogen in cow manure came from whatever they ate (grass, corn, soybeans...) and those crops, except for the soybeans, were mostly fertilized with "synthetic nitrogen." The cow is just passing a bit of that along.

Why Organic Needs Conventional

Organic farmers are limited to non-synthetic sources of nitrogen fertilizer.  They can supply some of that through biologically fixed nitrogen produced by legumes as main crops, cover crops or green manure crops.  Still, the reality is that many organic crops (fruit, vegetables, corn, wheat...) are fertilized with animal manures or composts thereof.  Organic growers are allowed to use manures/composts that come from conventional animal sources.  This is necessary because otherwise, organic farmers would be severely nitrogen limited.  Organic agriculture is actually quite dependent on manure from animals fed with non-organic crops.

Manure Isn't Such A Great Fertilizer Anyway

Manure is also a non-ideal fertilizer in many ways.  Cows and other animals are better at getting the nitrogen out of their feed than the phosphorus, so manures generally have too much phosphorus if they are applied at rates sufficient to supply a crop the nitrogen it needs.  That phosphorus can then become a ground or surface water pollution issue. The best way to utilize manures is to supplement the nitrogen with synthetic sources to better balance with the phosphorus.

Manure is also a source of bacteria that are human pathogens.  That is why it needs to be composted to be safer for use on human food crops.  But there are enough methane emissions during composting to be highly problematic from a greenhouse gas point of view.  When manures are incorporated into farmed soils they can also lead to more greenhouse gas emissions as methane.

Also, much of the nitrogen in manure is not in a form that the plant can use until it is "mineralized" into the ammonium or nitrate ions that plants can absorb (also what is in "synthetic" nitrogen fertilizers).  Mineralization is dependent on the activity of soil microbes and they don't necessarily release the nitrogen at the time of the growing season that the plant needs it the most.  In a recent meta-study of research on organic vs conventional crop yields, the authors observe that to come closer to conventional yields, it was necessary for the organic program to use more total nitrogen so that during the period of peak demand it was not as limiting (sorry, it is behind a pay wall, but the authors were willing to share a full copy when I wrote them).   Of course, in such cases the extra nitrogen would also be mineralized at times when the crop was not demanding it, leading to more surface or ground water pollution or to greenhouse gas emissions (nitrous oxide).

Conclusion

So, cows (or sheep or pigs or chickens) are not actual net contributors to our demand for fertilizers.  They just temporarily retain a bit of the supply generated for their feed.  We need sources of nitrogen to enable crops to harvest solar energy and turn it into a form that we can use.  We need the nitrogen to make the proteins that we need for growth and brain development.  We need to make good use of the nutrients that are left in animal manures, but they are only ever going to be a small contributor to our overall fertilizer needs.

You are welcome to comment here and/or to email me at applied.mythology@gmail.com

Cows image from Wikimedia

A Defense of Plant and Crop Related Patents

Patents involving plants are often portrayed as a seriously negative phenomenon.  In fact, they play an important and beneficial role in the development of better and more productive crops.  As I have watched the controversy around the role of patents, particularly as related to biotech crops, it seems that critics have little understanding of why the patent system was created in the first place, how the patent system actually works, and what patents do and don't mean in the commercial realm.

I would like to explain why, rather than being some sort of sinister tool of conspiratorial control, patents on plant varieties and on biotechnology innovations are key drivers of the investment and creativity that we will need if we are to meet the food supply and environmental challenges that lie before us over the next few decades.

The Grand Patent Bargain

Patent systems were set up to provide creative people with the incentive to invest their time, money and talent in the development of inventions that could benefit society.  To do that, the following bargain was struck:  the inventor gets a specifically limited period with the exclusive right to derive economic returns from the sales/use of the invention only if they meet two standards.  First, they must make a sufficiently strong case that their invention demonstrates "novelty," and second, they must fulfill "the obligation to teach."  I'll unpack that below.

Proving Novelty

To receive a patent, an invention has to "exhibit novelty" meaning that it is different from similar inventions ("in the prior art"), and that novelty has to be something that is "non-obvious to one skilled in the art."  Anyone who has ever pursued a patent knows, it is quite hard to meet that standards.  Even after a patent is awarded, the novelty question can - and frequently is - disputed in court if the patent turns out to have any significant economic ramifications.  As I heard in my first company-sponsored training on the subject, "a patent is only a license to be sued."  The effort and originality involved in patenting of plant lines and of genes is often spoken of as if it is some trivial, and thus undeserving activity.  That is only believable if you've never engaged in the process.

The Obligation to Teach

When someone develops something new and hopes to profit from having done so, the main alternative to patents is what is called a "trade secret." If you pursue a trade secret strategy, you hope that the details of your product or process are sufficiently obscure that others can't imitate it.   To get the more certain period of exclusivity offered by a patent comes with a requirement that you explain your invention in detail sufficient to allow any qualified reader the ability to understand exactly what it is and how it works.  This "teaching requirement" is actually the genius of the patent system. To get temporary exclusivity, you have to reveal information that will very often give competitors ideas about how to do something even better or otherwise "work around" your patent.  Also, often years before a patent can get through the process to be awarded, it is"published" so that what you teach is available to everyone else sooner than you get the patent or even if you never get it. The system forces a level of idea-sharing that would never have happened without it.

In my paying job as a technology consultant (as opposed to time I spend blogging), I frequently help companies monitor what their competitors and the academic community are doing in a specific area of science.  I find that recently published patents are an extremely useful window on such a question (try this yourself on the search page for the patent office.  type something like ttl/rose to see how many patent applications have been filed just for roses).  Mind you this is not a collegial exchange of information.  Between the dull, precise nature of scientific language and the obtuse nature of lawyer-speak, patent applications must be in competition for the most tedious form of writing (I know because I have to read these).  Still, it is a form of real idea exchange that is forced by the patent system.  The grand bargain works for the benefit of society.

Who Patents Plants and Plant-related Technologies?

The modern anti-biotechnology narrative would have you believe that certain companies (Monsanto usually being portrayed as the ultimate demon) are using patents in some new paradigm to "control the food supply." This view ignores the fact that plant variety patents have been a common feature of crop genetics since 1970 and that a great many of those patents are held by universities, by the USDA, and by similar international agencies (Patents for vegetatively propagated plants have been an option since 1930).  Actually, the most foundational tools of biotechnology for plant, pharmaceutical or industrial use were patented by scientists at Stanford University.  For a time, any group that did genetic engineering needed a license to the Stanford-held, Cohen-Boyer patents that are now considered a "gold standard" for university licensing.

When, in the 1990s, commercial biotechnology entered the agricultural seed market space, the fact that such products were patented was nothing new.  For decades, commercial, academic and government researchers have typically patented their inventions.  None of this is sinister.  If someone develops a crop variety that has real economic value to farmers, it does not matter whether the innovation originated in the public or private sphere, it may well be patented.  For any entity to take the following steps to commercialize that trait, the temporary exclusivity afforded by a patent makes it worth their effort and investment to do so.

How Much "Control" Does A Patent Provide?

A patent on something like a gene for potential use in a biotech crop means very little by itself.  There are typically many patents covering parts of or steps in the process of bringing that trait gene to the market - often patents controlled by different entities.  For instance, as soon as genetic engineering became a possibility in the 1970s, many groups were interested in finding a way to make plants resistant to the very broad spectrum, low toxicity herbicide - glyphosate.  It turned out to be difficult to get a form of the effected enzyme, EPSPS that would not be inhibited by glyphosate but which would still serve its normal function for the plant.  It ended up requiring two distinct changes at different positions in the enzyme.  The group that finally generated a modified gene that did the trick (designated as "CP4") worked for a small start-up biotech company in Davis, California called Calgene.  The investors and scientists there were rewarded for that breakthrough when Monsanto commercialized the trait.  Still, that was only the beginning.  For this enzyme to function properly it has to move into the chloroplasts in the cell.  That means it has to be linked to a Chloroplast Transit Peptide and the patent for that was awarded to a European biotech company (there were several major European players in the early days of this science).  Monsanto had to pay a royalty to that company for rights to use the patented sequence.

There are patents covering the steps required to actually get a new gene into a plant.  For some time, the preferred method of doing that has been with the help of an organism called Agrobacterium.  For many years, any company that wanted to use a special strain of that bacterium which would do that job with monocot crops (e.g. corn, wheat, rice...) needed to pay for rights to use a strain that was discovered by scientists at a Japanese company called JTI.

Once a gene is successfully inserted in a particular specimen of a crop in such a way that it is expressed functionally and does not cause any other problems, such an "event" is patented.  This still means little in the commercial realm.  Next the trait has to be "introgressed into elite germplasm," meaning it has to be crossed using conventional breeding methods to get that trait into many of the best hybrids or varieties which seed companies have developed for specific geographies and/or specific uses.  This part of the seed industry is very competitive for the crops which have been engineered to-date.  A company that has developed a new trait has the option of only commercializing in their own seed lines or of licensing it broadly even to their competitors.  Monsanto picked the later path with their Roundup Ready Soybeans, and even though farmers rapidly adopted the technology and used it in over 90% of what they planted, those seeds were purchased from many different seed company competitors whose elite germplasm was every bit as important for the sale as that one trait.

Of course patents have a finite term.  For instance, the key patents covering the original Roundup Ready Soybeans will expire in 2014 and Monsanto will have no future control of those lines.

Patents also don't always block uses.  When Cornell University developed virus resistant papayas that could save the Hawaiian industry, Monsanto gave them rights to certain necessary patents for free.  Similarly, many companies have waived their patent rights for technologies involved in "Golden Rice."

Behind Each Patent, There Are People

Part of why I am so positive about the role of patents in agriculture is that over the years I've had privilege of meeting many of the individual scientists who have been involved in the inventive process of plant biotechnology - the sort of innovations that can be patented.  The people I have met/known have innovated in both small and large companies, in universities and in the USDA and if you met them you would be impressed with both their scientific acumen and their positive ambitions for making a societal contribution.

Cohen and Boyer taught sections of a biochemistry class I took at Stanford in the late 70s.  One of the inventors at Calgene that found the CP4 gene worked in the neighboring lab when I was a graduate student at UC Davis.  One of my previous employers had a partnership with JTI and I met scientists at their plant biotechnology center that came up with the monocot-specific Agrobacterium strain.  I have done projects in which I met several university scientists whose inventions were licensed by the companies that commercialize biotech and other crops.  I've met many of the scientists in the big ag/biotech companies and interacted at various stages of biotech crop development from ideas to full commercialization.  I wish you could meet these scientists.

From what I have seen, the potential of patent protection has been an extremely important driver of creativity and of getting the resources necessary for scientists to be creative.  In every case what I've seen involves scientific rigor, real-world problem solving, and excitement about being able to make a contribution.

I've seen universities get a stream of money to support additional research because of a patent they were able to license.  I've seen small companies reward their staff and investors because of important patents they generated.  I've seen the advanced level of scientific effort that is possible in large companies for whom the potential of patented products allows a high rate of plowing profits back into research - something that does not happen in the companies that sell generic products.

Based on all these experiences, I cannot share the concerns that are being so widely expressed about the role of patents in agriculture.  In fact, I cannot imagine a path forward without them.

You are welcome to comment here and/or to email me at savage.sd@gmail.com

Patent image from Wikimedia commons

Soil Building: The Key To Sustainable Farming

Will we will be able to meet the growing global demand for food over the next few decades?  Will we be able to do that in a way that does not degrade the environment?  Surprisingly, the answers depend on how well we manage the soils we farm.

Soils are not just dirt.  They are dynamic living systems with highly complex physical and chemical properties.  Whether they are healthy and have desirable features depends on how they are tended, and historically many farming practices degraded soil quality rather than improved it.  Fortunately, over the past several decades we have learned a great deal about how farmers can significantly build the quality of this critical resource.  It is extremely important that this knowledge is extensively applied (I will be specifically addressing the situation for the millions of acres of rain fed, row crop land in the American Midwest).

What A Healthy Soil Can Do For Farmers and the Environment

Healthy soils are rich in "large aggregates" - collections of the base minerals of the area (sand, clay, fragments of parent rocks, etc) which are held together with the living organisms and life generated complex polymers like humus from broken down plant matter and glomalin from beneficial fungal growth.  These aggregates are loosely arranged with many "macropores" created by past plant roots and by the work of earthworms and other tunneling organisms.  Water is able to quickly infiltrate into the soil, even after heavy rains or rapid snow melt,  and be stored for later use.  Because of the rapid infiltration and the aggregated structure of the soil, there is little, if any, runoff that moves at a velocity which would carry silt, fertilizers or chemical residues into neighboring streams.  A healthy soil is thus more "drought proof" and far less likely to contribute to water pollution issues.

Because of the macropores, a healthy soil is better aerated. Oxygen is available for the needs of plant roots and there are fewer instances where oxygen becomes limiting.  That leads to better crop growth and far fewer events where anaerobic soil microbes make the "trace greenhouse gases" nitrous oxide and methane which are a major part of agriculture's contribution to climate change. Healthy farmed soils can, under certain scenarios, "sequester" carbon dioxide from the atmosphere - something which could, over hundreds of millions of acres - be a significant mitigation strategy for climate change.

Healthy soils are also lively places with many fungal and bacterial symbionts that help plants better absorb nutrients and biologically "fix" their own nitrogen supplies.  Some also help to suppress pathogens and nematodes that might otherwise damage their roots.  Between the cycling population of microbes and the stable soil aggregates, a healthy soil is a good buffer for the nutrients that plants need - preventing them from being wasted by moving to surface or ground water, and evening out the supply over time.

How Does Nature Build Healthy Soils?

It turns out, not surprisingly, that the best way to build soil in a place like the American Great Plains is to imitate the way that nature builds soil.  Before that region was put under the plow in the 1800s, the prairie grasslands of the US Midwest had wonderfully healthy soils - particularly in the Northern tier where the parent mineral base is deep and well drained because of the influence of glaciation in the last Ice Age.  Nature builds soils from the top down.  The above ground parts of plants from each season fall onto the ground and slowly decompose.  In the meantime they protect the soil from the splashing assault of rain drops and they block the evaporation of moisture from the soil surface.  Natural soil building does not involve physical disturbance - things like plowing.  The other main feature of the prairie ecosystem was that there was a mixture of perennial and annual plants growing and feeding the soil biosystem via their roots for as many frost-free days as each season allowed.

Normal row crop farming involves a great deal of soil disturbance.  The crop residues were normally tilled under at the end of the season leaving the soil exposed.  Some weeds might grow between crops, but the soil is not being fed nearly as much as in a prairie ecosystem.  Finally, the soil is compressed by the passage of heavy farming equipment.  Under these conditions soils tend to decline in quality over time.

How Can Farmers Imitate Natural Soil Building?

Starting in the 1960s, farmers have been developing ways to farm that don't involve much if any tillage or other disturbance of the soil.  Crop residues are left on the surface where they protect against erosion and block evaporation.  The full season soil feeding of a grassland can be imitated by the planting of cover crops which grow between one harvest and the next planting.  These cover crops can include legumes that help to produce nitrogen for the next crop or alternatively they can scavenge nitrogen or other nutrients that remained in the soil both to save them for release in the next crop cycle and to prevent them from becoming pollutants.  Without periodic tillage, soils can become compacted.  Fortunately, GPS and even more sophisticated guidance technologies, now allow farmers to practice "controlled wheel traffic" meaning that no tire ever drives over most of the area of a field so that soils remain well aerated.  Precision fertilization can then ensure that no nitrogen fertilizer is placed in the compacted tracks so that it is much less likely to be released as nitrous oxide.  A combination of these practices: continuous no-till, cover cropping, controlled wheel traffic and precision fertilization does a very good job of increasing soil quality over time.  These soils are more "drought proof" because they capture and store water better.  They are more fertile because of nutrient buffering in the improved organic matter.  Over time, the "weed seed bank" is diminished because tillage does not keep exposing more seed.  These soils are very good at preventing pollution of both surface and ground waters with nutrients.  They can, under the right circumstances, lead to a net sequestration of carbon in soils.

How Does This Compare With Soil Building in Organic Farming Systems?

The founders of the organic movement early in the 20th century were far ahead of their time in their appreciation of the importance of building soil quality.  Although it is not a required element for organic, cover crop is a more common practice in organic.  However, one of the main ways that organic farmers improved soils was by bringing in large quantities of manure, compost or other organic amendments and tilling these into the soil.  This practice does in fact improve soil quality over time, but not in any way that imitates nature and it has its own environmental issues.  Because organic farmers have little if any option for herbicides, tillage has been the main way that weeds are controlled.  Recently there have been efforts to develop a "roller-crimper" system to do no-till in organic.  The most practical use of a roller crimper by be in combination with herbicides (as has been a practice in no-till systems in South America).

So How Much Of This Kind Of Soil Building Farming Is Happening?

Some, but not enough.  I don't want to imply that it is easy for a farmer to manage land in the way described above or that it is a one size fit all solution for every situation.  It takes the integration of many technologies and presents its own set of practical challenges.  Although such a system is ultimately more productive and more stable, there can be difficulties during the transitional period. Residue covered soils can be slower to warm in the spring and can harbor different pests.  It is logistically difficult to get a cover crop planted during the busy harvest season.  Specialized equipment is required.  All of this is further complicated by the fact that most modern farmers lease a substantial proportion of the land they tend - typically on an annual cash rent basis.  The building of soil quality is a wise long-term investment, but only if a farmers knows that he/she will be the one tending that land in the future.  Although there are very significant areas being farmed with one or more of these ideal practices, the full suite of soil building approaches are probably only being applied on a small percentage of the total area.  There is a real need for developing more enlightened and long-term land lease structures and agricultural credit policies to enable more farmers to be in the business of building soils for the future.

Cover crop image from USDA-Natural Resources Conservation Services.  No-till corn image also from NRCS

You are welcome to comment here and/or at savage.sd@gmail.com.  To learn of future posts follow @grapedoc on Twitter.

The Muddled Debate About Pesticide Use And GM Crops

Does the adoption of GM crops lead to more or less pesticide use?  This is a frequent topic of debate, but generally one that misses the point.  Both sides make the same erroneous assumption that all pesticide use is, by definition, a bad thing.  In fact, it depends on the particular pesticide in question, the reason it is being used, and the details of its application.  Most modern pesticides are extremely low in hazard to us or to the environment.  Both "sides" of the GM debate would do well to stop over-simplfying this issue.

What Biotech Can and Can't Do

In his recent speech expressing regret for his former role in the anti-GMO campaign, environmentalist Mark Lynas cited cases where biotech crops reduced the need for pesticide applications (e.g. Bt Cotton and Bt Maize).  The examples are quite positive from the farmer's point of view.  However, for crops with biotech insect resistance, pesticides remain an important and well regulated tool for farmers who still have to deal with many other pests for which there may never be a biotech solution.   The supporters of crop biotechnology need to maintain the perspective that biotech traits are simply one tool in the tool box.  There is no excuse for ignoring the science behind advances in pesticide risk management any more than for ignoring the science behind risk management for GM technology.

Putting "Increased Pesticide Use" Into a Global Perspective

Jason Mark recently posted a "rebuttal" to Lynas' speech on Earth Island Journal.  It relied on exactly the sort of "self referencing" sources that Lynas critiqued, but one argument struck me as sufficiently absurd to warrant a response:

"A peer-reviewed study published last year in Environmental Sciences Europe found that GM plantings in the United States led to a 7 percent increase in chemical spraying."

Seriously? A European publication expressing angst about an incremental change in US pesticide use on its major crops? Do they know about the intensive use of pesticides on crops in Europe? (see graph below).  Actually, it is the study by Chuck Benbrook of the Organic Center in the US which generates a seemingly large number until you consider that his model includes use on hundreds of millions of acres over 16 years).


Why do European farmers use so much pesticide?  The reason is simple: they have to deal with lots of pests!  As with farmers everywhere, those in Europe face insects, weeds, fungi, bacteria and viruses which, if uncontrolled, diminish the amount of food that they can produce.  They farm in a generally wetter climate, and so they need lots of fungicides.  Like any farmer, they use the highly regulated pesticide options available to them so that they can limit the damage from those pests.  If they didn't use those pesticides, they would be making inefficient use of their land and of other necessary inputs like fertilizers and fuel.  As it is, Europe imports a great deal of its food and feed (206 million metric tons for the top 20 commodities imported in 2010).  When European farmers use pesticides to be as productive as possible, they at least help to minimize that strain on the global food supply.

Putting "Increased Pesticide Use" Into Quantitative And Contextual Perspective

The 7% increase Environmental Sciences Europe cites as an offshoot of GM crops mainly involves a herbicide, glyphosate, which happens to have a benign profile in terms of toxicity to things other than plants.  The transition to glyphosate for "Roundup Ready"crops replaced the use of sulfonyl ureas, a class of herbicides which had extremely low use-rates.  Thus, the still modest glyphosate use rate of 22-44 ounces of product per acre represented a small increase in total "pounds on the ground." Ken Cook of the Environmental Working Group responded to Lynas with a post in which he describes these crops as being "slathered with chemicals."  The 44 ounce rate means that each liquid ounce is spread over an area of almost 1,000 square feet. The active ingredient is applied at less than 0.01 grams per square foot.  Somehow, that does not fit my mental image of "slathered."

The far more relevant point is that glyphosate tolerant crops represented a more practical alternative to mechanical tillage for weed control and enabled wider adoption of "no-till" farming.  That is a system which conserves soil moisture, prevents erosion, dramatically reduces nutrient and pesticide movement to streams and rivers, and reduces fuel use.  If biotechnology and herbicides can combine with sophisticated equipment to enable this sort of farming - all the better.

Bottom line, a biotechnology trait may decrease or increases the need for a pesticide.  There will also be many cases where the biotech trait has nothing to do with pesticide use.  There is no necessary good or bad linkage between these two categories of agricultural technology - both can serve to make crop production better.  Both are options that should be available to those who farm.

You are welcome to comment here and/or to write me at savage.sd@gmail.com.  My Twitter feed is @grapedoc

Sprayer image from North Carolina Crops

Eight Technologies Keeping A Carcinogen Out of Your Food

Safe, Tasty, Nutritious Almonds We Shouldn't Take For Granted

Sometimes we need to hear about things that are working well in our food system.  I'd like to describe a case where sound regulation and well-applied technology combine to protect us from a significant risk posed by a natural chemical called Aflatoxin - one of the most toxic and carcinogenic chemicals known.  Aflatoxin can contaminate a wide range of foods from maize (field corn), to peanuts, to cotton seed meal, to tree nuts (almond, walnut, pecan, pistachio), to wild collected nuts (Brazil nut), to dried peppers to various spices. It can even be in chocolate! For those that live in "The Global South" (or developing world), aflatoxin is one of the leading causes of illness and death - particularly through liver cancer.  If you live in the richer parts of the world, you may never hear about this toxin. Strict regulations, combined with a suite of technologies and testing protocols, do a very good job of protecting us from this threat.  I'd like to describe them, but first I need to talk about...

The Bad Guys In This Story

This threat of contamination involves a "conspiracy" between a fungus, an insect, and the climate.  Ok, its just biology, but it is still insidious.  Insects, particularly caterpillars, damage crops by feeding on them.  Certain species and strains in the fungus, Aspergillus, are able to infect parts of plants that are damaged by the worms.  The fungus produces the toxin as a means of excluding other microbes from that damaged site.  For many crops (particularly maize,) drought or heat stress increases the susceptibility of the plant to this sort of attack.

Navel Orange Worm Larvae in a Nut

In some crops (particularly tree nuts), the insect and the fungus strike a mutually beneficial pact.

A caterpillar called the Navel Orange Worm actually transports the Aspergillus fungus with it when it feeds on developing fruiting structures of the nut tree.  This worm has a phenomenally effective P450 enzyme that detoxifies the aflatoxin to which it is exposed so that both partners are protected in their niche by the toxin.  These are formidable foes, but fortunately not insurmountable when the following technologies are deployed.

Technology 1: Analytical Methods

A number of companies have developed various analytical tools to fit various parts of the system.  Rapid, cost-effective, and robust tests are available that can be used by non-experts to exclude contaminated loads before they enter the supply at somewhere like a grain elevator.  Very sensitive and precise tests are available to check the end product to meet even the high EU standard for nuts of 2 parts per billion aflatoxin.  The Gates foundation is funding development of very low cost tests to extend this life saving capability to the developing world.

Technology 2: Orchard Sanitation

There is an important "low tech" component to managing this threat.  In nut orchards, the Navel Orange Worm overwinters in "mummies"- the damaged and colonized fruiting structures which tend to stay attached to the tree, unlike the healthy nuts which are shaken loose during harvest.  

Mummies (dark) left from the previous season harbor the Navel Orange Worm

It is very important for the growers to remove as many of the mummies as possible from the trees and to destroy as many as possible of those that fall to the ground.  Workers walk through the orchard with long bamboo poles to knock down as many mummies as they can.  In a recent study in Pistachios, it was determined that a threshold of 0.2 mummies/acre was desirable to keep worm populations low enough.  That would mean that between 99.965% to 99.977% of the nuts and mummies need to be removed by either harvest operations or subsequent sanitation.

Technologies 3 and 4: Insecticides and Mating Disruption

For the nut crops, the best strategy (in addition to doing the orchard sanitation) is to use two, well-timed insecticide sprays along with mating disruption - essentially putting out lots of sources of the Navel Orange Worm's mating hormone so that the males get completely confused and unable to find the females.

In a large scale, three year study (see graph above I made from their published data), the combination of insecticides and mating disruption provided the best control of the worms and thus greatly reduced the introduction of the fungus.

Technology 5: Biotechnology (Marker Assisted Selection)

Marker assisted selection is essentially conventional plant breeding except that the breeder knows which specific genes are being moved around.  This is a side benefit of decades of investment in better and better laboratory tools for biotechnology (used in plant and medical technology). As an example, it has been used by Syngenta to develop more drought tolerant corn, and that will potentially lower aflatoxin levels.

Aspergillus infection of corn like this can be prevented with insect and drought resistance traits

Technology 6: Biotechnology (GMO)

There is also a GMO drought tolerant corn from Monsanto that will first enter the market in 2013, and this should also help reduce aflatoxin.  The more dramatic effects are seen with insect resistant corn lines (available from several companies).  If the worms (European Corn Borers in this case), can't feed long enough to damage the ears of corn, then the Aspergillus can't follow and produce the toxin.  This was observed quite clearly last year.

Technology 7: Biological Control

One very cool strategy developed by USDA scientists is finding strains of Aspergillus which compete well at colonizing insect damaged plant tissues, but which don't make the toxin.  These are called "atoxigenic strains", and they are introduced into the field as pellets that sporulate and allow these benign strains to find their way to the plants.  Syngenta, is now offering this product as Aflaguard.  The combination of the biocontrol agent and biotech-based insect resistance proved to be a particularly effective combination for maize in the 2012 drought.





Technology 8: Fluorescence Detection

With crops like tree nuts or peanuts, there is one more step that can be taken to deal with infections that slip through the other control measures (remember there is an almost zero tolerance for this issue). Shelled nuts are carried, one-by-one, at high speed, down a conveyer belt past a source of light that has a wavelength that will produce fluorescence at another specific wavelength if Aspergillus is present on a nut.  If that signal is picked up with detectors, a perfectly timed puff of air knocks that nut off the line.  This is why I always prefer to buy shelled nuts because they typically go through this process.  This procedure is also commonly used for peanuts going into peanut butter and other confectionary uses.

A great deal of effort goes into minimizing risks associated with aflatoxin in our food supply.  Extending these sorts of protections to the developing world is not easy, but is a much needed change.

You are welcome to comment here and/or to email me at savage.sd@gmail.com.  You can also follow me on Twitter (@grapedoc).

Almonds image from HealthAliciousNess' photostream. Pistachio mummy image and Navel Orange Worm in nut image from the University of California.  Aspergillus infected corn image from Iowa State University. Biocontrol image from USDA-ARS

The Shocking Carbon Footprint of Compost

Most people think of composting as a very "green" thing to do, but few realize that composting actually generates a significant amount of the potent greenhouse gases (GHG), methane and nitrous oxide.  Under current landfill regulations, requirements to exclude water minimizes the breakdown of organic matter and requirements to capture and burn methane mean that even that option has a better carbon footprint than composting (thanks to Fred Krieger for pointing out this advance in the landfill arena).  The even better option is anaerobic digestion which I will describe at the end of this post.

These Emissions Are Not A Scientific Surprise

To a microbiologist, it is not surprising that these gases would be generated during composting. Methane and nitrous oxide are formed by certain microbes when there is not enough oxygen available (anaerobic conditions). In the middle of a large-scale compost pile there are micro-sites without oxygen. This occurs even in a pile turned frequently for aeration. This is particularly true during the "hot" phase of the composting process which kills pathogens and weed seeds. During the period of very high oxygen demand, some parts of the pile will run short and the anaerobic organisms will make methane and nitrous oxide.

Counting the Cost of the Anti-GMO Movement

Last week, environmentalist Mark Lynas presented an articulate and painfully honest apology for his significant role in starting the anti-GMO movement in the 1990s.  He said that it was the most successful campaign in which he has ever been involved, but after finally looking into the science, he now deeply regrets what he and others accomplished.  While it is gratifying to have a figure like Lynas make such a turn-about, it does nothing to mitigate the damage of which this anti-science movement has perpetrated on humanity and the environment.  Ideally, such a dramatic reversal will induce others in the movement to rethink their positions. but this sort of openness to letting the science speak into bias is likely to be rare.

Lynas is right that anti-GMO campaigners have been extremely successful at blocking, delaying, or destroying potential crop improvements via biotechnology.  Lynas had a lot of ground to cover in his speech, so he only gave four examples of the ways that his previous movement has achieved its ends:

• In Europe, politicians influenced by the anti-GMO movement ignored the input from their own scientists to adopt hyper-precautionary and obstructive regulatory barriers to the technology. They have thus limited the ability of their own farmers to satisfy more of the substantial demand that the region puts on global food supplies.

• The European stance has greatly influenced the policies of many developing nations in Africa and Asia.  Such "rich world thinking" denies poor farmers the advances that could significantly improve their food security.  See Robert Paarlberg's excellent summary of this phenomenon in his book "Starved for Science."

• Phobia-driven (or publicity-seeking) vandalism by anti-GMO extremists has delayed or halted several crop innovations by destroying experimental field plots (e.g. Greenpeace "actions" against biotech wheat, or the destruction of a French field trial of grape rootstocks). 

• The anti-GMO movement has intensified the regulatory environment so that the cost of biotech crop development now requires the resources of a large company. This reduces the potential contributions from smaller start-ups, academics or government sponsored programs. 

Beyond what Lynas described, there are other mechanisms by which the anti-GMO movement has frustrated biotech crop progress.  The threat of controversy generated by anti-GMO campaigners leads to various forms of brand protectionism which can become a non-regulatory barrier to technology adoption:

• The threat of protests has been most effective when applied to companies with major consumer brands and enough market leverage to dictate what happens for a given crop.  The classic case of this phenomenon was how MacDonalds, in three phone calls to major frozen French fry producers, put an end to biotech potatoes in the US and Canada.  Potatoes are an extraordinarily difficult crop to improve through breeding because of their complex genetics and vegetative propagation.  Biotechnology was a promising way to deliver traits for important pest issues as well as quality and health benefits, and the major potato buyers knew it.  However; the risk from brand-damaging protests drove the decision. 

• The specter of consumer backlash (fanned by anti-science propaganda) concerned major wheat importers/millers in Europe and Japan.  Their response was to threaten to boycott all North American wheat if a single acre of commercial GMO wheat was planted.  US and Canadian growers, faced with such a significant drop in export sales, reluctantly asked Syngenta and Monsanto to halt their biotech wheat programs.   For the future the US, Canadian and Australian wheat industries have all decided to block any future blackmail threats by doing a simultaneous launch of biotech wheat when and if it becomes available.  In the mean time there has been a multi-decade delay for positive technologies for one of the most important of global food crops.

• Anti-GMO campaigning has made the entire topic of "GMOs" sufficiently toxic that the growers/marketers of many crops wish simply to avoid any impact on their crop's "brand" in the consumer market place.  This is what we are seeing today in the US/Canadian apple industry where a small, grower-based company has developed an innovative, consumer oriented trait.  The nervous industry has reacted quite negatively because of concerns about the apple "brand"  even though those biotech apples would only reach the market advertised specifically as biotech-improved.  This sort of thinking has also effectively blocked the use of biotechnology to solve problems in grapes as well as in most other fruit and vegetable crops

Opportunities Lost

There is a long and growing list of agricultural, environmental, and health improvement that "could have been" if the anti-GMO movement had not been so effective.  Some of these are only "nice to haves" like a fine wine.  Some of them are significant advances such as potatoes that ward off their major insect and virus pests.  Some of them are things like wheat which is less likely to have mycotoxin contamination.  Some of them are things that could enable poor farmers to produce more local food with less need for inputs or more resistance to environmental stresses.  

What Mark Lynas realized is that it is just as detrimental to the future of humanity to ignore the scientific consensus on crop biotechnology as it is to ignore the scientific consensus on climate change.  The fact that there are groups successfully blocking rational action on both these fronts presents a synergistically dire threat to efforts to feed humanity.

Addendum 1/7/13

In an ironic twist, today on the way into a computer store I was approached by a young, Greenpeace worker.  She asked, "Are you familiar with Greenpeace?"  I said, "Yes, I'm a serious opponent."  She said, "That probably means you won't want to sign my petition!"  I concurred and encouraged her to listen to the Mark Lynas speech which I described because she had not heard about it.  I hope she does because her sincere energy to do something good is being twisted into something seriously bad.

You are welcome to comment here and/or to email me at savage.sd@gmail.com.  To get a message about future posts follow @grapedoc on twitter.

Source of GMO Protest Image - University of Washington