Friday, April 29, 2011

Organic Or Not?

Today’s post will review the effects of crop management system (organic or conventional) on several points of interest: productivity, nutritive content, groundwater contamination, pesticide residue, soil quality, and carbon footprint. The topics more closely related to organics in beef production will be covered in posts dedicated to antibiotics, hormones, and E. coli 0157:H7 (oh, my!) later.

1)      Introduction
First law of thermodynamics: energy cannot be created or destroyed, it can only change form. There is no such thing as low-input systems (commonly, organics) producing high outputs. While energy spent on conventional agriculture (such as that used in producing inorganic fertilizer) may change form in organic agriculture (increased labor for composting, manure and compost application, weeding, mulching), crops still don’t magically appear – it still needs soil nitrogen for growth (see post: “…Determined to Succeed!”), and nitrogen accumulation requires energy (carbon). Less cannot equal more.

Fuel vs. labor costs may in part determine the cost of conventional vs. organic production. More machines doing work at a lower cost means more people are free to choose an education, a profession, or a location of their desiring…then again, less people are receiving pay as farm workers…because less costly food is produced which is affordable for more people…thus, a dilemma emerges. Life is full of dilemmas in a zero-sum, no-free-lunch world.    

2)      Productivity
There is little argument that conventional agriculture produces more food per acre than organics. This means that, in a conventional system, more can be grown on less land—which is good, since only 25% of the surface of our planet is land. Take tomatoes for example: 1000 kg organic vine tomatoes = 122 square meters of land vs. 1000 kg conventionally-grown loose tomatoes = 19 square meters.

Studies consistently show that organic grain and soybean harvests are 20 – 40% less than conventional (not limited to…Cavigelli et al., 2007; Halberg and Kristensen, 1997; Mäder et al., 2002) Perhaps one or two years of organic cropping compared to one or two years of conventional cropping might produce similar crop yields (i.e., studies from the Rodale Institute, Badgley et al., 2006). These are the types of studies often cited by those who are pro-organic, but longer-term comparisons of both systems consistently show yield deficits (from 10 – 40%) within organic systems compared to conventional (Smolik and Dobbs, 1996; Shepard et al., 1996; Mader et al., 2002). Even one of the most pro-organic scientists of our time, Dr. David Pimentel, agrees that it has not been proven that organics can feed the world: “Avery et al. imply that I reported that all US and world agriculture could be grown organically without commercial nitrogen fertilizer. They are incorrect—I never said this in my review, nor have I ever said this in any one of the more than 500 scientific papers I have published” (2005). Remember that compost and manure does not really add to soil fertility, it maintains soil fertility by recycling, and it does so with diminishing returns. What does merit further study is the use of legumes (beans, alfalfa, clover…) to fertilize soils enough to replace synthetic fertilizer use, as Badgley et al. suggest (2006). 

3)      Nutritive Content
A meta-analysis (a study of 55 studies) concluded that there was no difference between organic and conventional produce in protein, antioxidants, Mg, Ca, P, K, Zn, Cu, and Vitamin C (Dangour et al., 2009). Another meta-analysis (on 45 studies) showed no human health superiority from an organic vs. conventional diet based on antioxidant status, breast milk composition, cancer cell proliferation, and other biomarkers (Dangour et al., 2010).

4)      Pesticide Residue
Part of the USDA organic certification process requires a 3 year withdrawal period from any unnatural pesticide use on farmland. If the neighboring farm uses inorganic pesticides and the wind carries its residue to the certified Organic farm, the organic farmer is held liable. Therefore, Organic produce will consistently have lower pesticide residues than conventional produce (Baker et al., 2002). Curiously, this doesn’t mean organic produce has zero residues. Some pesticides in use by the conventional systems and any pesticide used by organics will be biosynthetic (deemed safe at any concentration by EPA). All pesticide products bear a labeled statement that reads something like "For use up to ___ day(s) before harvest". This is the time period that is required for the compounds to deactivate and decompose into an EPA-deemed "safe" level. The EPA and FDA stringently regulate pesticide use and test produce for residues. Click here to see an example of a report. Pesticides include herbicide and insecticide. Herbicides are compounds that disrupt plant-specific processes. Herbicides will only affect you if you contain chlorophyll or can you produce your own essential amino acids (essential = can only come from your diet; Duke & Powles, 2008); if you possess these attributes, you should seek medical attention immediately. Certainly, the preparation and application of insecticides and fungicides can be dangerous, which is why I had to train for and obtain my pesticide applicator’s licence in order to purchase and apply industry- grade chemicals. There is less of a consensus about insecticides and other animal pest management compounds, especially for its effect on young children (NRC, 1993). However, no quantifiable evidence of short term or long term exposure to pesticide residue (within EPA/USDA tolerance levels) from produce demonstrates any deleterious effects on human health. Finally, everyone should wash their produce, regardless of its “organic” status, before consumption anyway.

5)      Bacterial Contamination
Organic foods are more at risk than conventional foods for bacterial and parasitic contamination because they rely on compost and manure to fertilize soil (Rembialkowska, 2007). Additionally, mycotoxins (poisonous fungi) are more apt to grow in organic crops because fungicide use is prohibited. On the other hand, Williams and Hammond (2001) found that there was a reduced risk in bacterial contamination within organic foods. Risk does not always translate into reality, of course. Organic farmers do well to aerate their compost to keep any harmful bacteria at bay. If you’ve never been worried about this before, don’t worry about it now, just keep washing your food like you always have. And please wash your hands. Food is no different than everything else in life that can transmit microbes.

6)      Groundwater Contamination
Per unit of food produced, phosphorus and nitrate groundwater loading were found to be the same for organic and conventional systems based on a meta-analysis by Mondelaers et al., 2009). Per unit of land, however, Mondelaers et al. (2009) found that organic systems usually have less nutrient-loading. Another study compared systems with equal land units and found that nutrient loading was the same regardless of organic status (Dufault et al., 2008). The point of either system is to produce food, so a pound of food as a functional unit provides the most valid comparison.

7)      Soil Quality
No-till systems using herbicide (conventional) are said to be the best at conserving soil quality (Soil and Water Conservation Society, 1995, as cited by Avery et al., 2005). Tillage required by organic systems increases soil erosion. However, soils in organic systems often have higher organic matter content since plant residues and manure are often added to the soil in these systems, displaying a positive effect on soil health (Mondelaers et al., 2009). Studies have been confounded by varying tillage practice within organic and conventional practices.

8)      Wildlife Biodiversity
Organic farming is positively associated with improvement in wildlife (wild and rare plants, more bugs, more birds up and around the field) compared to conventional (Mondelaers et al., 2009). Yes, pesticide abstinence tends to coincide with more bugs, more birds to eat the bugs, and more “wild plants”.

9)      Carbon Footprint
The differences between organic and conventional “carbon footprints” (fuel use efficiency) are unclear (Gelfand et al., 2010; Johnson et al., 2007) Certainly, no-till systems rely less on machinery (e.g., tractors, tillers…). However, organic systems don’t use synthetic fertilizer, which relies on fossil fuels for its manufacturing. The fuel efficiencies transportation of goods within either systems is highly variable as well. Presumably, then, taking food production as a functional unit, the conventional system may win out on fuel efficiency per unit produced. Too many confounding factors impede a sound conclusion as to which system is truly more “green.”

Again, what is sustainability: the ability to prolong the human population indefinitely; or, in other words, the ability to “feed the world” (which, of course, implies the responsible management of resources). In pursuit of this, shall we intensify what we can produce on less land by choosing conventional, thereby preserving land from cultivation? Or, shall we less intensely impact a larger land area with organic cultivation? Perhaps we can settle on this: we cannot conclude that either organic or conventional farming is absolutely superior to the other at this point. More likely, the two systems have much to learn from one another. What do you Think?

Thursday, April 21, 2011

Unacceptable.

A national animal rights group, Mercy For Animals, released undercover video footage of dairy calf cruelty yesterday. Farm hands were given an executive order by their supervisor to euthanize calves that were exposed to and crippled by severe winter weather. Instead, video evidence shows them striking blows to the animals' heads with hammers. This activity is utterly intolerable within the livestock and dairy industries, but somehow it was captured and conveniently used to promote this message:

"Boycott animal abuse. Choose vegetarian."

Here are my questions.
1) Were the farmhands prodded on by the undercover cameramen?
2) If abuse was suspected, why did a pre-meditated framing occur instead of a true investigation?
3) Why would anyone claiming to love animals so much mildly stand by and watch through a video lens instead of so easily intervening to stop the killing or persuade them to use a more humane method?
4) Why was an agenda prostheletyzed at the cost of animal lives?

What do you Think?

Friday, April 8, 2011

...Determined to succeed!

Nitrogen—catch it if you can. It’s the component in manufactured (inorganic) fertilizer that is responsible for as much as 60% of crop yields in developed countries (Stewart et al., 2005), and is responsible for feeding 48% of the world population (Erisman et al., 2008). It is a critical component of amino acids and nucleotides, which form life’s hardware and software, respectively. Yet nitrogen can readily change from a form that plants utilize to one that is nonreactive, like nitrogen gas (78% of air we breathe), or a reactive, ozone-depleting, greenhouse gas, the ever-nefarious nitrous oxide. Nitrogen can also leach out of soils as nitrate, which can enter waterways and cause algal blooms that decompose into hypoxic dead zones in oceans, to the chagrin of aquatic life, tourists, and fishermen. Moreover, nitrogen fertilizer can be one of the most expensive input costs in crop production, and nitrogen losses are detrimental economically as well as environmentally. Since nitrogen (N) is usually in the wrong place, in the wrong form, at the wrong time, soil scientists and agronomists have been following nitrogen molecules for decades (literally, with isotopic labeling), trying to impede its losses and promote its capture by plants.  

Organic farming systems use recycled N by fertilizing with composted organic waste and manure, or rely on legumes (alfalfa, clover, beans…) to draw in nitrogen gas from the air and convert it to plant-usable forms.

Conventional systems rely on compost, manure, and legumes also, but primarily fertilize soil with N by adding synthetic fertilizer. Fossil-fuel-generated heat converts nitrogen gas to ammonia nitrate and other N-containing fertilizers in the manufacturing process. This is why synthetic fertilizer prices are so sensitive to energy prices.

One system yields 7 – 35% more food than the other system (Alex Avery, Hudson Institute, 2009), being also responsible for reducing starvation rate from 1/3 in 1965 to 1/7 in 2010 (FAO), but we’ll open that can of worms next week!

Following the advent of industrial ammonification in the last century, it was generally thought that “more was more” when it came to fertilization and farming. Over-application of N exacerbates nitrification and denitrification losses (Watson et al., 1992). No one realized this until research like that performed by Stout et al. (1974) showed that “less is more” by graphing the points of diminishing return for fertilizer and crop yields. Beyond a certain point, applying N is simply wasteful and harmful. Even as N application rates are more precise and are performed as indicated by soil tests, N still tends to escape the field by way of natural processes. Here are the discoveries that have mitigated challenges by nitrification (nitrate leaching) and denitrification (gaseous N).

More ways to reduce nitrification (nitrate leaching):
Less N leaches out of clay than sandy soils (Macduff et al., 1990)
Development of nitrification inhibitors (Singh and Verma, 2007)
Splitting the total N application into several small applications for crops, while and not before they are growing (Alcoz et al., 1993)
Dry application of fertilizer is better than dissolved in water (Pratt et al., 1976)
Practice no-till or conservation tillage (Drury et al., 2004)
Crop rotation (studies by Wright and Hons, 2004-2005)
Low-intensity grazing (Wright et al., 2004)
High soil organic carbon (Williams et al., 2001)
...

More ways to reduce denitrification (gaseous losses):
High soil organic carbon (especially from soils under conservation tillage) significantly reduces nitrous oxide emissions (Bijay-Singh et al., 1988)
...

You may notice that no-till farming systems promote efficient capture of nitrogen…as well as sequester more carbon to reduce atmospheric CO2. Unfortunately, organic farming relies heavily on tillage to combat weeds, which of course frustrates this whole scheme of N and C capture. Then again, in organic systems, soil carbon accumulation by manuring, mulching, and cover-cropping is more common. Next topic will be much more consumer-friendly, since we’ll debate organic vs. conventional!

What do you Think about all this farm chemistry today?   

Bitten hands that feed...

Communication and mutual understanding tumble easily into the wide chasm between the 2% who produce food and fiber in this country and the other 98% of Americans. People usually fear most what they don’t understand and aren’t familiar with.

Furthermore, consequences induced by the great Ag vs. Non-Ag Sector divide have led to misfortune and lowered morale for many agricultural producers. The few that bear responsibility for feeding the many also bear an unequal share of legislation, public scrutiny, and law enforcement, while city dwellers often get let off the hook. When it’s rural political power vs. urban political power, majority rules.
                             
      A Share of Legislation 
      California, Proposition 2 passed in 2008. The law, which will go into full effect in 2015, decrees that laying hens must have enough room in their cages to fully stretch their wings, lie down, and turn in a circle. That sounded good to 63% of California voters (ironic: 63% of Americans are pet owners…i.e., if they owned chickens, they’d probably carry them around everywhere and paint their toenails, too…wait, like I DID!). No one thought one more step ahead to wonder:
  1. Why it could have made sense to house hens in that way (see comments and Hard to Swallow)
  2. How the birds laying the inevitable $2/dozen egg imports would be treated
  3. How many struggling families may have to forgo eating eggs because of higher costs
  4. The gargantuan start-up costs for those wanting to remain in or enter the business 
…and what we have now is a massive outsourcing of food, i.e., a national security issue. Schwarzenegger pledged that any imported eggs would also be made according to Prop 2. Really? Where’s the egg in the McMuffin coming from, and will it be on the Dollar Menu? 

A Share of Law Enforcement
So, a city-dweller would never expect the EPA to issue a fine for exceeding a bacterial Total Maximum Daily Load  because your dog is using the backyard as a toilet and it’s entering the drainpipe when you turn the sprinklers on. An example of urban bacterial sources are as follows: 38% waterfowl; 26% humans + pets; wildlife 24%; rats 11%. Sometimes pets can contribute as much as 40% of the bacteria. Ugh, and you can also compare total bacterial output by source.

If a rural-dweller owns livestock, however, even though livestock bacteria only make up 22% of the total bacteria in a waterway, that person is held accountable. An example of rural bacterial sources are as follows: Pets, 8%; Septic leaks, 11%; non avian wildlife, 29%; avian wildlife, 7%; cattle, 22%; unknown, 10%; avian livestock, 1%; other non avian livestock, 12% (data courtesy of Dr. Redmon and Mr. Wagner, TAMU) Better keep a close eye on those ducks, people.  

And can you believe it, the EPA wants to regulate dust production on agricultural property? They can, since 2% of the population is relatively easy to regulate.

A Share of Public Scrutiny:
It is also curious that agricultural greenhouse gas emissions (6%) receive more attention than electricity generation (76%), transportation (11%), and manufacturing (4%). Or, with regards to methane production, cattle always come up in conversation, even though these are the statistics: natural swamps (26%), rice paddies (20%), fermentation by cattle and other livestock (15%) oil, gas, coal leaks (14%), biomass combustion (10%), landfills (7%), and animal waste (3%; Heilig et al., 1994, Houghton et al., 1990, as cited in Wahlen et al., 1993)

Is agriculture getting a fair share of legislation, enforcement, and scrutiny? What do you Think?

Friday, April 1, 2011

Cattleman's Stewardship Review

Did you know that the U.S. beef industry produces 20% of the world’s beef with only 7% of the world’s cattle? That the production of a pound of grain-finished beef uses 45% less land, 76% less water, 49% less feed, while producing 51% less manure and 42% carbon emissions than producing a pound of grass-finished beef? That more than $30 million of the industry’s own money has been spent on beef product safety and E. coli research (although it costs you and me $0 to cook beef to 160°F and kill pathogens)? If you’re curious about the beef industry in general, or animal, human, environmental and local economic health, visit this online handbook, the Cattlemen’s Stewardship Review. Read to see what you Think.