Modern agriculture faces some huge challenges. Human population is rapidly growing, world hunger is a real threat, and industrial activity has caused environmental problems, including global warming and mass extinctions of species. Organic agriculture promises to provide solutions to these challenges. Let's have a closer look at it and evaluate its claims.

Organic agriculture is a production system for products such as fruits, vegetables and meat, that promises to support the health of ecosystems, of the soil and of people. Unlike conventional agriculture, which aspires to maximize yields and minimize costs, organic agriculture strives to integrate quality and environmental values in the production process.

Organic produce is usually considered healthier than conventional produce, because people assume it has more vitamins and antioxidants, and no remenants of pesticides, antibiotics and other harmful chemicals. Many consumers prefer organic produce for its emphasis on reducing its environmental impact and for its avoidance of genetically modified organisms.

In 2005, the Israeli Ministry of Agriculture introduced a bill that regulated organic agriculture, and added statutes for producing organic products. This legislation followed the fast development of the global and domestic organic markets, and the need to adapt Israeli standards to international norms.

Pros and Cons
So is organic agriculture really the way to a better agriculture? Can it feed the number of mouths that need to be fed, and maintain human health and the environment at the same time? To answer this question fully, we need to evaluate organic agriculture's pros and cons, with respect to conventional agriculture.

Organically grown lemons | Photo credit: Ralf Roletschek, Wikipedia

To be a proper alternative to conventional modern agriculture, organic agriculture needs to face four challenges:
1. Its products should have a higher nutritional value than those of conventional products
2. Production should be environmentally friendly, non-toxic, free of pollutants, and it should maintain soil "health"
3. No pesticides or other bio-active materials should be included in organic produce
4. It should provide at least as much yield per area of land, compared with conventional agriculture.

The scientific evidence doesn't clearly support all of the claims of organic agriculture. Still, some recent, well-respected scientific reviews of the subject allow us to look at this topic closely, examine evidence for each of these claims, and decide which agriculture is better.

1. Higher Nutritional Value
The nutritional value of a food depends on many environmental factors, including the type of soil or feed, the weather, the age of the plant or animal, the time of harvest, the length of storage and more. Many studies which show advantages to either type of agriculture are deeply flawed, and should be treated with great caution.

Recently, some meta-analyses of previous studies were published with surprising results. (These are studies with compile all the data from several other studies and examine the entire dataset statistically.) The studies found no significant difference in the concentrations of vitamins and antioxidants in the bodily fluids of organic product consumers compared with other consumers, indicating no substantial nutritional advantage to organic products over regular products.

2. Environmentally Friendly Production Methods
To conform with market demands and be profitable, agricultural industry uses synthetic plant fertilizers and animal hormones to control plant and animal growth.

Organic food advocates frown upon this practice, and point to the harmful effects of synthetic nitrate and phosphate compounds used in fertilizers on the environment, including groundwater pollution. Scientists are trying to find a solution for this problem, but practically, there is no way around using fertilizers in any form of agriculture.

Notably, organic fertilizers are approved by organic agriculture, though. These are mostly organic leftovers from the meat, poultry and dairy industries, including "flours" made of animal organs. The use of these fertilizers contradicts the declared goals of organic agriculture, because supporting animal-based fertilizers supports the animal agricultural industry, one of the most polluting industries on earth. Animal waste is one of the major causes of groundwater contamination, and has other harmful environmental effects.

Likewise, the evidence is inconclusive on whether organic fertilizers reduce nitrogen runoffs, and some evidence points to the opposite claim. Phosphates and their derivatives have been found to be in higher, but still clinically safe, levels in organic products compared with conventional products.

Organic fertilizer in the field | Photo credit: Wikipedia

Other materials used in organic agriculture for plant protection are actually chemically inorganic compounds, such as sulfur or copper compounds that are very toxic for fish. In other cases, chemically organic compounds are used without regard to their dangers, such as plant extracts containing natural pyrethrines. Sometimes, due to the fertilizers' low efficiency, higher quantities have to be used, and harmful environmental effects may be exacerbated.

With respect to maintaining soil quality, recent studies are inconclusive. Some point to higher carbon residuees in organically grown fields, and others found no difference.

So far, antibiotic resistance appears to be the only area in which organic products seem to have an advantage over conventional products, as organic crops have been conclusively shown to have less antibiotic-resistant bacteria. Along the same lines, raising animals without antibiotics reduces the chance of evolving resistant bacteria.

3. Lack of Bioactive Pesticides in Produce
Researchers agree that pesticides are harmful for both animals and humans. However, recent technological developments have made them more effective and less toxic for the environment and for people.

So far, no cross-sectional studies have shown any significant connection between long-term exposore to pesticides at levels beneath the allowed quotas to neurodegenerative or hormonal diseases in people or animals. Most reported clinical cases are related to exposure to very high levels of hazardous materials.

A long-term study conducted on about 90,000 people in Iowa, USA showed that most cancers occur at lower levels among farmers who use synthetic pesticides regularly than the cancer rate in the general population. The minor increases in several types of cancer could not be conclusively shown to relate to exposure to pesticides, but rather could have resulted from working in the sun or from increased exposure to viruses and other pathogens.

Nevertheless, despite all the technological improvements, the reduction in the use of pesticides and the strict regulations put in place, pesticides are still a major pollutant in both organic and conventional agriculture. A study published in "Haaretz" found traces of banned pesticides in some organic plants sold in Israel. Likewise, a review of the scientific literature reveals very few studies on the environmental and health implications of organic pesticides. As it is, there is no way for us to know if organic pesticides are healthier than conventional pesticides, or if they are less healthy.

Another topic worth discussing in this context is biological pest management, based on insects that prey on agricultural pests. This is particularly common in organic agriculture, but is also used in conventional fields.

Coccinella septempunctata, the seven-spot ladybird, a beetle used in biological pest management | Photo credit: Wikipedia

Biological pest management can reduce the need for chemical pesticides, but it can turn sometimes into a double-edged sword. Introducing organisms into a new environment can create invasive species and immeasurable economic damage, and even cause extinction of local species and otherwise irreversibly change the ecosystem they were introduced into.

Animal organic farmers are also proud to say they inject no growth or sex hormones into the animals. In practice, however, the benefits of avoiding this are dubious. Long-term studies have shown that the growth hormone given to cows is safe for human consumption, because it can only affect cattle, and not humans. Also, when we eat it, it mostly breaks down in the acidic environment in the human stomach. Furthermore, studies have also shown that the hormone doesn't change the quality or chemical composition of milk.

Moreover, the growth hormone may have positive environmental effects, as it raises the yield of milk per cow, so less cows are needed to produce a given amount of milk. Research also indicates that bovine sex hormones are safe for human consumption, and that they are found in similarly low concentrations in both conventional and organic products. Like the growth hormone, they may also ultimately have a positive environmental effect.

To sum up the evidence so far, we can conclude that only very limited scientific evidence can support the claimed health and environmental benefits of organic agriculture.

4. Equal Yields
A broad and in-depth study published in Nature magazine shows that organic agriculture has lower yields per unit area than conventional agriculture. Although the extent of the difference varies by crop, geography and other factors, the Nature study indicates that in some cases, going organic can cost up to 30% of the yield.

Data collected in the Israeli organic agriculture industry paints a similar picture, and other studies support Nature's findings. This clear disadvantage has severe implications for the environment: Having to clear more land for fields may increase global deforestation, and larger fields require more people, more machines, more fuel, more fertilizer, more pesticides and more water.

Two other factors that increase the gap between conventional and organic yields are genetic engineering and hydroponics. These methods hold promise to require less pesticides, water and fertilizer, to do without agricultural land and produce higher yields. However, the standards of organic agriculture do not allow for crops that were genetically modified in modern methods, or crops that were grown disconnected from the soil in any way.

Hydroponically grown onions | Picture credit: NASA

Genetic engineering have allowed for producing drought-resistant, salinity-resistant and pest-resistant plants, and for increased yields per area. Some people, such as Nobel peace prize laureate Norman Borlaug, believe that it may solve world hunger. Yet most organic food advocates will have nothing to do with genetically modified crops.

Public ignorance and misunderstanding of genetic engineering is dangerous. Obviously, this topic should be treated carefully, but wholesale bans of genetically modified organisms in agriculture could deprive humanity of possible ways to mitigate world hunger. What's more, ignoring genetic engineering's benefits could also needlessly exacerbate agriculture's environmental impact.

All in all, there is room to doubt organic agriculture's ability to make good on its promises. While it promises to be sustainable and provide for all hungry people on earth, and to benefit people, nature and the soil at the same time, the (admittedly partial) scientific evidence paints a very different picture. We have no way to conclude that organic agriculture outperforms conventional agriculture. In fact, in some ways, it does worse.

Dr. Haim Haviv
Davidson Institute of Science Education
Weizmann Institute of Science

Article translated from Hebrew by Aviv J. Sharon, M.Sc. student at the Weizmann Institute of Science.

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