Synthetic agricultural chemicals became commonplace beginning with the s--called "Green Revolution" in the second half of the 20th century, but their benefits haven't come without environmental costs—namely the wholesale pollution of most of our streams, rivers, ponds, lakes and even coastal areas, as these synthetic chemicals run-off into the nearby waterways.
Image: Roger Smith, courtesy Flickr
-
The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
Read More »
Dear EarthTalk: What effects do fertilizers, pesticides and herbicides used on residential lawns or on farms have on nearby water bodies like rivers, streams—or even the ocean for those of us who live near the shore?
-- Linda Reddington, Manahawkin, NJ
With the advent of the so-called Green Revolution in the second half of the 20th century—when farmers began to use technological advances to boost yields—synthetic fertilizers, pesticides and herbicides became commonplace around the world not only on farms, but in backyard gardens and on front lawns as well.
These chemicals, many of which were developed in the lab and are petroleum-based, have allowed farmers and gardeners of every stripe to exercise greater control over the plants they want to grow by enriching the immediate environment and warding off pests. But such benefits haven’t come without environmental costs—namely the wholesale pollution of most of our streams, rivers, ponds, lakes and even coastal areas, as these synthetic chemicals run-off into the nearby waterways.
When the excess nutrients from all the fertilizer we use runs off into our waterways, they cause algae blooms sometimes big enough to make waterways impassable. When the algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic species can’t survive in these so-called “dead zones” and so they die or move on to greener underwater pastures.
A related issue is the poisoning of aquatic life. According to the U.S. Centers for Disease Control (CDC), Americans alone churn through 75 million pounds of pesticides each year to keep the bugs off their peapods and petunias. When those chemicals get into waterways, fish ingest them and become diseased. Humans who eat diseased fish can themselves become ill, completing the circle wrought by pollution.
A 2007 study of pollution in rivers around Portland, Oregon found that wild salmon there are swimming around with dozens of synthetic chemicals in their systems. Another recent study from Indiana found that a variety of corn genetically engineered to produce the insecticide Bt is having toxic effects on non-target aquatic insects, including caddis flies, a major food source for fish and frogs.
The solution, of course, is to go organic, both at home and on the farm. According to the Organic Trade Association, organic farmers and gardeners use composted manure and other natural materials, as well as crop rotation, to help improve soil fertility, rather than synthetic fertilizers that can result in an overabundance of nutrients. As a result, these practices protect ground water supplies and avoid runoff of chemicals that can cause dead zones and poisoned aquatic life.
There is now a large variety of organic fertilizer available commercially, as well as many ways to keep pests at bay without resorting to harsh synthetic chemicals. A wealth of information on growing greener can be found online: Check out OrganicGardeningGuru.com and the U.S. Department of Agriculture’s Alternative Farming System Information Center, for starters. Those interested in face-to-face advice should consult with a master gardener at a local nursery that specializes in organic gardening.
CONTACTS: CDC, www.cdc.gov; Organic Gardening Guru, www.organicgardeningguru.com; USDA’s Alternative Farming System Information Center, www.nal.usda.gov/afsic/pubs/ofp/ofp.shtml.
EarthTalk is produced by E/The Environmental Magazine. SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php. EarthTalk is now a book! Details and order information at: www.emagazine.com/earthtalkbook.
See what we're tweeting about
14 Comments
Add CommentResponse is unbalanced and plays into the hands of people who would seek a return to the 1800's. There is so much left out, one is at a loss as to where to begin the critique. Could be be better stewards of the land and water? Of course we can and should, but unless you like worms in your plums, peaches, cauliflower, blighted crops galore, prices 3, 4, 5 times higher that they are today, then don't throw out the pesticides, herbicides, and chemical fertilizers just yet. There is hunger throughout the world today and real fear that food production in the future will not be sufficient for a growing population. Go ahead and destroy the balance, but first sign the agreement that you will be one of the multitude that will yeald your share of the food down the road, when the "cheese gets binding."
Reply | Report Abuse | Link to this"Organic" fertilizer? Plants need nitrogen and phosphorus to survive and grow. If, for instance you use manure for its (mainly) nitrogen content, yes, that helps the plant just like a synthetic nitrogen compound. And if you spread lots of that manure where it will run off into a stream --- you get the idea.
Reply | Report Abuse | Link to thisIf the nitrogen is in a soluble compound like ammonium nitrate, then run-off is likely, again, if used too much and too near a waterway. If it's in a less soluble form like urea, less likely.
I don't want any of them upstream of my campground, but I do want to eat. At least the synthetic stuff doesn't carry e. coli et al.
The problem has been specified: fertilizers have negative externalities by polluting water bodies. The solution, of course, is to go organic. What?! Anyone with half a scientific brain would fill in the middle part between problem and solution. This reminds me of: how did the human form come to be? The solution, of course, is an intelligent designer. I digress.
Reply | Report Abuse | Link to thisAre there ways to change fertilizers impacts? Can the geography of farms be changed? Et cetera. Examining the problem, analyzing constraints, ranking solutions by their impacts (negative and positive), this is the missing middle part, the most important part.
Could a revenue-neutral, fertilizer tax work? These are the kinds of questions that need exploration. Of course one can always keep asking is this the best way, but in this circumstance, that question has never been asked. Is growing organic the best way? The intellectually lazy jump to organics like a creationist. Our whole engine of growth, and a pillar of humanity, is finding the most efficient ways to solve problems - agricultural methods are not exempt.
Please remove this special interest article, it has no place in a scientific magazine.
Whenever there is any mention of organic growing critics always hark back to the 1800s. What they don't accept is that science has also played a part in developing naturally bred varieties that resist many common pests and diseases. The other big issue is that the total reliance on pesticides for food is doomed because it is oil based! What then for the lazy, unskilled growers whose only answer is to blast chemicals at anything that moves? To grow without pesticides requires a much deeper knowledge something that has been lost since the 'instant fix' was introduced less than 60 years ago. We just HAVE to move away from chemical soaked food to both survive the end of oil and to stop poisoning us and the planet.
Reply | Report Abuse | Link to thisYou can bet your life that there will be some lobbying from the agrochemical companies to have this removed. They don't like this sort of stuff and always say it's not 'scientific'. It seems the only science they know is that which supports their sales.
Reply | Report Abuse | Link to thisRoboc’s reply in no way contradicts my own. There is currently a market failure, farmers do not pay for their environmental degradation -- just how I don’t pay extra for my polluting car. In these circumstances, policy needs to be created to bring about optimality. What policy needs to be created here, with farming?
Reply | Report Abuse | Link to thisRoboc gives an example of how technology can be developed to increase farm yields without harmful practices. In a competitive environment I bet that all of these new methods are more expensive than their harmful chemical counterparts. Just how oil is cheaper than solar cells. Because it’s an unfair battle (market failure)! Policy needs to be set so the competition in the market brings about optimality for everyone. In the case of oil, set a carbon tax to make it more pricey (which most economists say is the most sustainable and effective way to reduce long run emissions). Granted, in some circumstances an all out ban is needed - like CFCs. With regards to oil and fertilizers, the solutions with the highest ‘positives’ would be a ban on oil totally, or a ban on fertilizers/pesticides totally, by tomorrow - stops all the harm the fastest! Hopefully it’s obvious that both of these ideas are very narrow. Banning oil tomorrow would cause mass blackouts and well, a lot of deaths. Ditto with fertilizers. Is there a solution which can bring about the same long-run sustainability with less negative consequences? What course of action should be taken to ween us off harmful fertilizers?
Developing those better organic farming methods could only be part of the solution, it is not close to being sufficient. What this article lacks is discussing, or at least acknowledging that wide gap. And as it’s closed, who knows if the current ‘unsupported’ ideals of the organic movement are indeed the necessary conditions for sustainable farming practices.
To clarify:
In the case of reducing emissions, the solution does not require knowing the specific technologies, it’s instating a policy, a process, which inevitably sets us on an effective course of reduction. The solution which will CAUSE us to stop using harmful fertilizers/pesticides is not developing more expensive, sustainable methods, it’s a policy, a correction of the market failure - i.e. a progressive pollution tax, a fertilizer tax, a ‘cap-n-trade’... It would be great if a competitive, ‘organic’ technology appeared miraculously, but why don’t we help it happen? Create greater incentives for investing in non-polluting practices. This is the solution.
>> In a competitive environment I bet that all of these new methods are more expensive than their harmful chemical counterparts. <<
Reply | Report Abuse | Link to thisWell no actually they are not especially if you include the hidden costs. But I don't find the cost argument holds water. Any polluter should pay for their pollution and if that increases the cost of food then sobeit. Why has 'cheap food' i.e. food that is 'cheap' in the shops become a right? What about all the hidden costs of pollution and health care? It's about time there was some honesty but I guess that's too much to hope for when such huge agrochemical profits are at stake.
Well that's exactly my point! The price of the harmful methods are cheap because pollution is cheaper, that's why it was done in the first place. If all those costs (which are pretty much undefined) were in the right place, then pollution wouldn't happen; spilling into a river would be more expensive than a treatment plant. But right now, treatment plants and new-and-improved plant species are more expensive on the marketplace. I never said anything about the right to cheap food. I completely agree that food prices should increase (like oil), but with the right solution the negative consequences of the transition can be minimized. My issue with the organic movement so far, is that it's a 'paper or plastic' decision. No thought is given to the dynamics of the problem, just unfounded, odd expectations that people will work in some borg-like groupthink of maximizing everyone's well-being. That's not human. How can the current organic farming practices suddenly replace these 'more efficient', harmful methods? And as I said before, there is no reason/justification that these nouvea methods hold any water. It is such a minority market, based off fad. What would agriculture look like if fertilizers cost 300% more? I don't know, but I bet there would be a lot less fertilizers seeping into rivers, and a lot of competition to create cheap, clean farms. It's not the agrochemical profits that will stop this from happening, it will be the lack of a sound plan to follow. Organic farming as it is, is a method/technology which caters to a specific rich, do-gooder market. It's not a solution to the fertilizer/pesticide problem. It's possible that some of it's methods may be necessary for sustainable farming practices, but they're irrelevant if the crux of the problem (addressing the market failure) is ignored.
Reply | Report Abuse | Link to thisIf you first compost the manure - let the microorganisms break it down out of its pure excrement form - it will kill off any disease causing pathogens and retain the same levels of nitrogen/phosphorus to be used as organic fertilizer. Composted manure and crop residue also significantly increase the water retention capacity of soil so that runoff is not a problem. Unfortunately inorganic compounds like chemical fertilizers can only continue to run off into our ground water supply, being water soluble, while depleting the earth's petroleum, phosphorus, and nitrogen supplies.
Reply | Report Abuse | Link to thisI'm not going to deny that farm policy and practices as they are today serve the purpose of mass production for an increasingly large population (though even with this some people eat too much and many, many more people don't eat enough), but there is a lot to be said for seriously exploring more sustainable options as our knowledge of fertilizers and their environmental effects grow.
>>How can the current organic farming practices suddenly replace these 'more efficient', harmful methods? <<
Reply | Report Abuse | Link to thisThat's an old assumption - that organic is less efficient. There has been research to show it's more efficient it's just that the agrochems like us to think otherwise so that they can then put out scare stories about how we can't manage without them. And you say lack of a sound plan will thawart organics, it will as long as the agrochems exert so much political influence government and people are scared into thinking there is no alternative.
"International Assessment of Agricultural Knowledge, Science and Technology for Development"
Reply | Report Abuse | Link to thishttp://www.agassessment.org/
I'm no fan of 'agrochems', but please enlighten me on what plan/policy they are hiding from us which can effectively stop their abuses. You misinterpreted what efficiency means: less money per increase in yield (which we both agreed upon earlier is true). And this is not meant to lambaste the efficiency of organic farming practices, it's just pointing out that they can't compete if we allow cheating -- farmers who take the cheaper route and pollute.
Reply | Report Abuse | Link to thisHowever, don’t get me wrong, the organic movement is merely at the stage of fad. If those who support it don’t start thinking more critically, bringing strong, viable solutions/policies forward, it will plateau at best, or just fall off to specialty food obscurity. The system is broken, expecting consumers to find it rational to switch over to ‘organic’ is naive. All these ‘organic’ practices are putting the carriage before the horse. And it’s this wrong order which loses my confidence. I’ll support the practices which come out of an efficient competition of farms forced to grow without negative externalities (pollution) -- not farms forced to grow x, y, z methods. Let the market find the best method that works, it’s the only sustainable way.
The market and competition of organic foods is very artificially constrained. To be labelled organic you need to follow this, this and this. It’s all based off differing guidelines. What real justification has been set to prove these guidelines are the most efficient way to feed ourselves (sustainably)? The organic industry is flawed, in that the efficiency is not being maximized against proper constraints. If there was a way to systematically create a growing pollution tax on farmers, then an efficient industry would be created. There would be no guidelines on best practices, but an innovation and competition for creating the best ‘guidelines’ and technology.
(... the same can be said for most ‘green’ issues: not understanding what is sustainable.)
a few details re: nutrients
Reply | Report Abuse | Link to thisA lot of the N is lost via ammonia volatilization during the composting process. This contributes to smog and moves to aquatic and terrestrial ecosystems, leading to acidification, soil degration and species shift .
Nutrients have to be soluble to be used by a plant. So, once the N in manure or compost converts to a plant-available form, it can also be lost via run-off, leaching etc. The "unconverted" form can also be carried away through wind and water erosion. Whether nutrients are applied in a chemical form or in an organic form, if you put on too much, in an incorrect time, or in an incorrect position, it can be lost and will not be used effectively by the plant.
Plants need N and P to grow. People need N and P to live. Harvesting a crop removes N, P and other nutrients from the field. It needs to be replenished somehow or the soil loses productivity and will not support life. If sufficient organic nutrients are around to replenish, that is great. But, considering that a perfect closed loop for nutrients isn't possible and people choose to live in cities where their wastes are not available to return to the land, we have a problem of nutrient depletion from soils.
Legumes can fix N and provide some N input at a field scale, but not enough to support the world population. Because legumes need to use enerby to supoprt the fixation of N by rhizobium bacteria, they do not produce as much edible product as cereal crops like the staples rice, corn, wheat, etc. Phosphorus cannot be "created" so must be brought in somehow to replace what is removed. Manure is a high source of P - often to high, leading to huge pollution problems in intensive livestock areas. But, the cost of transporting the P from manures the large distances to return it to where the crops that fed the livestock were grow is not viable. This loss of linkage is a major issue that has to be addressed somehow for sustainable production.
So, use whatever organic nutrients are available as efficiently as possible. But, unless inorganic nutrients are supplied as well, a good proportion of the human population will die. A recent estimate by Smil (2002) was that 40% of the worlds population is alive today because of the prouction and use of N fertilizers. The issue is to minimise the use of all nutrients, both organic and inorganic, by improving nutrient use efficiency, avoiding losses to the environment and making sure that healthy crops are producing as much as possible for every unit of fertilizer used.
This article oversimplifies and amalgamates dissimilar things and provides little ground for actually achieving progress on the ground.
Reply | Report Abuse | Link to thisA few salient facts:
* Fertilizers provide nutrients, whereas pesticides and herbicides help to protect crops from stress and competition. While ammonia is said to be synthesized from atmospheric nitrogen, fertilizers are not "synthetic chemicals" in the sense of pesticides or pharmaceuticals, which are novel molecules; the nutrient compounds found in fertilizers all exist in nature.
* The nutrients in "manufactured" fertilizers are exactly the same forms as those absorbed from manures and other "organic" fertilizers. However, they are already in the plant-available forms in the inorganic fertilizers and can therefore immediately benefit plants; their availability from organic sources is delayed by the need to convert them into forms plants can absorb.
* Therefore, excess applications of organic sources of nutrients are just as likely to pose an environmental hazard.
* Better management of nutrients is the solution to excess run-off. That means starting with whatever organic sources are locally available and complementing them with manufactured fertilizers as necessary (organic fertilizers have much lower nutrient contents than most people think, but they also provide non-nutritional benefits for soil health that manufactured fertilizers frequently do not).
* Just as organic nutrient sources and manufactured fertilizers can be used together in integrated plant nutrition management, mechanical and biological pest control can be complemented as necessary with chemical pesticides. It is false to say that organic farming does not use any chemicals; some are allowed.
Painting "conventional" agriculture as wholescale dumping of chemicals in the environment (farmers are not fools who want to throw their money out the window) and harking back to 18th century agriculture for organics are both inaccurate caricatures that do nothing to advance the debate about how to improve agricultural management to reduce unwanted impacts.
This article ignores the effect of scale. Organic agriculture accounts for about 1% of global cultivation. If it were scaled up to 99%, it would most certainly produce negative impacts that would need to be addressed. Indeed, global limits to the availability of plant-available nutrients would be a problem.
Improving agricultural sustainability means constantly innovating and adjusting practices to local conditions. These solutions are not one-size-fits-all or ideological.