Lately, there has been some interesting research making the news talking about the benefits of organic farms, and the risks of GM food.
Recently, a report on the Farming Systems Trial was released. This is a 30-year comparison of organic and conventional agriculture conducted by the venerable Rodale institute in Pennsylvania. We know that the effects of organic farming (especially changes in the soil) may not be visible in only a short trial. Farmers prefer that researchers study actual working organic farms, however, to do a true comparison you really need a research trial where you can look at two systems side by side.
Three different farming systems were studied:
- An organic rotation (corn, soybeans, corn silage, wheat and red clover-alfalfa hay) with added manure that would be common on a dairy or beef operation
- A shorter organic rotation including corn, soy, wheat and legume cover crops
- A conventional corn-soy rotation that used synthetic fertilizer, pesticides and (starting in 2008) GMO crops
All of the systems grew corn or soybean in their rotation so that researchers could compare between those crops.
This has been a really influential research project. Many researchers have used this trial to study the how organic farming affects crop yield, farm profitability, soil characteristics, greenhouse gas emissions, energy use, and effects on groundwater.
So what are the take-home messages? The report summarizes them as:
- Organic yields match conventional yields.
- Organic outperforms conventional in years of drought.
- Organic farming systems build rather than deplete soil organic matter, making it a more sustainable system.
- Organic farming uses 45% less energy and is more efficient.
- Conventional systems produce 40% more greenhouse gases.
- Organic farming systems are more profitable than conventional.
I encourage you to check out the report for more details about each of these points. But this photo was my take home message:
(Courtesy of the Rodale Institute 2011)
Isn’t it amazing? The soil on the left is from the organic trial, the soil on the right is from the conventional one. Research has shown that the organic systems have higher soil organic matter, microbial biomass, carbon, and nitrogen. In years with low rainfall, high yields from the organic system demonstrated the benefit to increasing organic matter – the organically managed soil holds water more effectively and resists drought.
This trial provides another example of how organic growers can compete with conventional farmers, and help better the environment too!
The second study that hit the news recently was a review of 19 different research papers looking at the effects of GMO crops fed to animals, published in Environmental Sciences Europe 23:10. The crops of concern (corn and soybean) included genes that allowed them to tolerate the herbicide glyphosate (Roundup Ready) or, in the case of corn, had other genes that produce their own pesticides. The authors reviewed the studies and performed a meta-analysis of rat toxicity data from several trials.
The findings were disturbing: liver and kidney problems were observed in animals in many of the trials, and the results tended to differ between males and females. So why are these crops having negative effects on animals? The researchers explain that the crops contain pesticides that are toxic, and the effects of this in the diet are emerging through poor weight gain and effects on organs. Roundup Ready crops have been engineered to survive being sprayed with this herbicide (glyphosate). The resulting crops have residues from the herbicide and can absorb the herbicide (and adjuvant) into their cells. Roundup has been shown to be toxic to hepatocytes, which are the cells that make up the liver.
Crops like Bt corn produce an insecticide themselves, through the insertion of mutated genes from Bacillus thuringiensis (Bt). So, you directly eat the toxin they are producing. In the trials reviewed, male rats fed Bt corn had smaller kidneys that were malfunctioning. While the results were statistically significant, many of the trials (including those sponsored by biotech firms) concluded that the results were too small to be ‘biologically significant’. The study’s authors felt this was dismissive of actual effects – if health effects were apparent after only a short trial, then long-term problems may emerge.
They also questioned if the methods used by some of the researchers were sound. Most of the research done used very few animals, and the feeding trials were three months or less. They suggest using longer toxicological tests that assess other parameters (such as hormones and reproductive effects), and test pregnant females and several generations to determine if the effects are chronic in nature.
Given the short duration of the testing of all of these GM crops, it feels like we are all part of a much larger research trial. It is good to see some researchers are beginning to question the science done by biotechnology firms and herbicide producers. It makes me more committed to eat organic whenever possible; the best way to eliminate your exposure to GM food and pull yourself out of the giant experiment!