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

What Would Be "A Food Movement Worth Of The Name?"

Back in October of 2012, author Michael Pollan wrote an opinion piece for the New York Times  in which he said the vote on California Proposition 37 would show whether or not the “Food Movement” had developed into “a movement worthy of the name.”  Proposition 37 failed for good reasons, but Pollan has raised a good question: 

What would a food movement worthy of the name look like?

Food is a tremendously important topic –necessary for survival, but critical in many other ways too.  Our diets influence our health in profound ways.  Food is also an integral component of culture, history and religion.  Food can be a source of great enjoyment and is an important medium for family and broader social interaction.  A worthy “Food Movement” focused on a topic of this importance should have at least the following positive goals:

·      The alleviation of hunger in the world.

·      Making sure that there is a safe, affordable and nutritious food supply

·      Helping people make good food choices for optimal health

·      Encouraging food production systems which are sustainable, just, and which have a minimal environmental impact

I’m sure that many who consider themselves part of the “Food Movement” aspire to these goals, but some of those who write, speak and blog for this movement tend to focus on what they are against more than what they are for.  Additionally, some writers are anti-scientific, inclined towards conspiracy-theory-thinking, and inclined to incite fear more than understanding.  

The Food Movement's Least Worthy Tendency

However, I believe that antipathy towards farmers is the least worthy characteristic of the current “Food Movement.”

If you reflect on the positive goals listed above, most are outcomes that can never be achieved without the critical contribution of those who actually produce the food.  By this I mean those that produce the 98+% of our food that does not come from small, local or organic farms.  While there are some foods for which localness is a real advantage, the fact that different foods tend to be produced in specific regions is because it makes the most sense to do so in terms of productivity, quality, and risk. Scientific and statistical evidence shows that organic is much less productive, and that it is not expanding in terms of acreage or production at least in our own country.  Organic is growing, but only in cost.

When many food movement advocates talk about farmers they tend to do so wielding epithets via terms, like “big,”  “factory”, “industrial,” “chemical,” or “corporate.”  They tend to imply negative or malicious or irresponsible motives.   Overall, they write about farmers in a way that indicates that they don’t actually know any of them.  I don’t think it is a good feature of any movement to dismiss broad groups with no real knowledge of those they are talking about.

What Modern, Large-Scale Farmers Are Really Like

I wish many of these writers could have the privilege to meet some of the farmers I have met over the years. Examples would be a grain producer in North Dakota with a 12,000-acre farm whose “office” is the kitchen table or the 5,000-acre grain grower in Kansas whose “office” was a desk in the corner of the machine shed with a brand new runt calf under a heat lamp next to it.  These are family farms operated by an individual or two brothers with maybe one hired hand and some family help at busy times of the year.  Between the economics, amazing equipment and the steady decline in the farming populations, this is modern farming, and it is just as noble an endeavor as ever before. 

I wish these writers could meet farm managers who work at multi-thousand acre vineyards or orchard companies in California that are actually “corporate farms”.   Like the grain farmers, these are all examples of technically sophisticated, business-smart, environmentally aware, generous and friendly folks who farm today.  Well under 1% of our population is directly involved in farming today.  Those who do are worthy of recognition, not demonization.

Farmers take on enormous economic risks each growing season with so many factors outside of their control (weather, commodity prices, pest outbreaks, new regulations…).   Rather than being armchair critics, it would be wise for Food Movement folks to assume that if farmers do something, there is probably a pretty good reason.  If they apply pesticides, it is because pests and their damage are real, and that failing to control them would compromise the production efficiency, quality and safety of their crop.  If farmers grow a certain crop or a biotech improved version of that crop it is because that is their most rational economic and risk/management choice.  The companies that sell seeds, equipment, chemicals or fertilizers to farmers can only do so if they create real value for their customers. Farmers are not stupid.  They only stay in business if they make good purchase decisions.   The products that famers buy support private investment in the development of better seed, better equipment and better crop protection chemicals.  There is nothing sinister about this.  It benefits farmers and thus, indirectly, all of us.

The Farmers Most Worthy of Food Movement Support

There are a great many “conventional farmers” who are on the cutting edge of environmentally friendly farming.  They use best practices like no-till farming and cover cropping to build soil quality and reduce off-site pollution. They use integrated pest management; fertilization via precision-variable-rate application for non-irrigated crops, or “spoon feeding” of nutrients via irrigation; or controlled wheel traffic (GPS and beyond) to avoid soil compaction and to reduce nitrous oxide emissions (greenhouse gas).   A “food movement worthy of the name” would be allied with this major group of progressive farmers.  Instead of railing at the farm community as a whole or at the companies that supply progressive farmers what they need, a worthy food movement might be brainstorming ways to change the farmland lease and credit systems which don’t encourage the sort of long-term thinking that is required for farming in the most sustainable fashion. 

Farmers are not the problem when it comes to important things about food or about legitimate goals of a worthy Food Movement.  Farmers are a critical part of the solution.

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

Pesticide Residues on Organic: What Do We Know?

Are there really less pesticide residues on organic crops?  The answer might not be as simple as you think.

A few weeks ago it was announced that for the first time in the history of USDA-Organic, there will be mandatory pesticide residue testing starting in 2013.  This was always a theoretical possibility, but a government audit of certifiers showed that it essentially never happened.  Now it will, at least to some extent (something like 5% of operations)

I wrote to the contact person at USDA to ask this question:

"will this new testing program look for any residues of the pesticides that are allowed on organic crop and thus applied frequently?"

Why Ask This Question?

Most consumers believe (erroneously) that organic crops are not sprayed with any pesticides at all.  That is not true, and the criterion for what can be sprayed on organic has nothing to do with relative risk - it is simply based on whether the pesticide is deemed "natural."  Knowing what is actually sprayed on organic crops, I was particularly interested in the copper-based fungicides because they are rather toxic by modern standards, and about Bt, protein insecticides because it would be helpful to calm people freaked out about Bt-biotech crops to be able to compare the exposure to this ultra-safe material when they probably consume farm more that is sprayed on crops vs when it is expressed by the crop.

Unfortunately, I learned that this new testing program is only there to encourage compliance with the organic rules, not to document anything about relative residue levels.  There will be no testing for organically approved pesticides.  In fact there won't be any public data-base generated and the sampling will be at the discretion of certifiers - not random.

This leaves us with the same situation we have had for a long time.  Organic advocates and marketers make regular claims about the advantage of organic with regard to pesticide residues, and yet there is no actual data to support that claim - at least not for the US.

But Didn't That Stanford Study Compare Residues?

Remember the recent "Stanford Meta-Study" comparing organic and conventional that stirred so much controversy?  They found lots of studies about nutrient content, but in their extensive search of the scientific literature they were only able to find 9 studies that compared pesticide residues in organic and conventional.  Only one of those was even from the US and it was from the mid 1990s.  It was based on a testing program at USDA called the PDP (Pesticide Detection Program).  While that group does an excellent job of monitoring pesticide residues on conventional crops, it has never looked for the pesticides most likely to be found as residues on organic - things like copper salts.  So even that one study that the Stanford group cited for the US was not a meaningful piece of data for residue comparison.  So much for the scientific literature as a source on this question.

Why Doesn't the PDP Test For Copper, Bt, Biologicals Etc?

I contacted the USDA scientists who run the PDP to ask why they don't test for things like Copper fungicides, Bts or other biologicals.  The answer was quite practical.  They use something called multi-residues methods (MRMs) with which it is possible to simultaneously test for 2-300 different synthetic pesticides in a single analysis run.  However, because of solubility issues and detection technology differences, many organic-approved pesticides cannot be extracted or measured by the same protocol.  To do the testing for these individual categories of pesticides would be far too expensive for the budget of that agency.  The random sampling method of PDP is also not well suited to getting enough organic samples for comparison.

Can We Compare Residues?  No.

So, here is where we stand on the question of pesticide residues on food.  The conventional supply is rigorously tested for the main products they intentionally apply as well as for any off-label or environmentally persistent products left over from the bad old days.  We get a data set every year which essentially says that there isn't anything to keep consumers from confidently buying that food.  The organic food supply is going to be tested to some degree for the first time, but we won't see any real summary of that data nor will we be able to compare it to conventional.  We also know that there won't be any data generated about the pesticide residues most likely to be present on organic.

Do We Know Anything About Pesticide Residues On Organic Crops?

There was a relatively small, but high quality pilot study conducted by the USDA as background for their new testing regime.  The authors were careful to point out the multiple reasons that their data is not really comparable to PDP (limited number of crops, smaller sample size not collected in the same fashion, fewer chemical tests conducted...).  What they did find was that there were definitely some synthetic pesticide residues detected on organic crops - mostly consistent with spray drift, accidental contact in packing houses, persistent environmental pollutants....  The levels they found were not problematic from a safety point of view, but that is just as true for the PDP testing of conventional crops.  This pilot program was like the PDP in that it used MRMs and so it didn't test for the majority of organic pesticides.   So, bottom line, we still have no real data about the most likely pesticide residues that occur on organic crops and we are unlikely to get any.

What Would Happen If We Could Get Information About Organic Residue Status?

If organic were subjected to the same level of random and comprehensive testing that is used for conventional, and if all its pesticides were included, it would almost certainly come out "dirty" by the absurd and irresponsible methodology employed by the Environmental Working Group to create its annual "dirty dozen list".  They just count detections without regard to the nature of the chemical in question or its concentration or its EPA tolerance.  If there ever were a comparable pesticide residue database for organic it would force a far more scientific discussion of which residues matter and which do not.  My guess is that both conventional and organic would come out as just fine for consumers to eat, but the "organic advantage" would disappear when both types of food had to be compared using scientifically sound assessments.

Bottom line.  Just eat your fruits and vegetables and whole grains.... enjoy them!

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

Organic produce image from Pculter's Photostream