Publications (Paul's Blog)

September 13, 2011

Filed under: Uncategorized — Paul Dowlearn @ 3:43 pm

Apologies to Al Gore, but it has occurred to me lately that what the world needs now is Al Gore on nitrates. Without a doubt, the silver lining of Mr. Gore’s controversial loss to George W. Bush was that after conceding defeat, he then turned his talents and considerable resources to educating us on another controversial subject: atmospheric carbon (CO2). Due to this herculean effort we are now well aware of the carbon cycle, carbon emissions, carbon footprints, carbon sequestration, and so forth. The impact of “An Inconvenient Truth” compelled worldwide response. We now have some laws in place plus some alternative energy incentives. Heck, even Exxon/Mobil is promising us algae as a new energy source. Politicians are now willing to talk and debate the issue in contrast to a mere decade ago when the subject was largely ignored. At least some progress is being made. Thank you, Mr. Gore.
Now we need a person with the same dedication and passion to take up the issue of nitrates. Most of you are aware of the infamous “dead zone” that occurs where the Mississippi River drains into the Gulf of Mexico. While certainly not the only dead zone created by nitrates flowing from the rivers of industrial nations, it is the second largest (worldwide) and therefore a major concern to those who make their living from the Gulf.
The Gulf dead zone now occupies some seven to eight thousand square miles, depending on whose stats you read. Remarkably, the 2009 dead zone shrank to around three thousand square miles even though it was predicted to do otherwise. Clearly, there is much to study and learn.
In one recent report, a University of Michigan zoologist, Nathaniel Ostrom was asked his opinion as to whether the highly publicized (and analyzed) Deep Horizon oil spill would have greater impact than the dead zone, he replied, “It’s a really tough call.” So the nitrate problem which has been with us for some time may actually be as bad if not worse, over the long run, than the recent oil spill.
Speaking for myself, I am rather fond of seafood and would rather continue to enjoy it. “Eat more fish; Live longer,” was a popular T-shirt slogan I remember from my youth, apparently not so true today. Dead zones support no fish, shellfish, or marine life of any kind save some algae. Since this dead zone keeps growing in size, my opinion is that unless we take action, it eventually will be a greater threat than the oil spill. So what is being done and what can you and I as average citizens do to help?
First we must seek an understanding of nitrates and where they come from. That begins with the nitrogen cycle. You can find a fairly easy to understand explanation at this address . What you will learn is that just as with the carbon cycle, our human habits are influencing the nitrogen cycle in a very negative way.
To begin with, free nitrogen (N2) is a double molecule that comprises a large part of our lower atmosphere as an inert gas. Some 78% of all nitrogen resides in the gaseous state and in this form is unavailable to plants and other life forms. In Nature, nitrogen is put into useable (or reactive) forms by bacteria (rhizobium and azotobacters). This bacterial process is called “fixing nitrogen.” Also, in the superheated air around lightning and air pressure changes that result in thunder, the twin nitrogen molecules will separate so they are now free to attach to oxygen molecules to form nitrate (NO3) or hydrogen to form ammonia (NH3). This explains why plants grow so well after a good rain. It is said that rain events with plenty of lightning contain around 4% nitrogen products by volume. Remember that number.
During World War One, we were cut off from our natural mined source of nitrate (urea) that was used to make explosives. Scientists got busy and learned to mimic the heat and pressure changes produced from lightning by using natural gas. This became known as the Haber-Bosch process which produced high levels of ammonium nitrate. After the war, ammonium nitrate was used as a fertilizer that contained high levels of nitrogen. In more recent history, these fertilizers were used to make “fertilizer bombs.” Terrorist organizations still use fertilizer bombs.
The nitrogen levels achieved by this petrochemical synthesis are far greater than nitrogen levels from natural or organic sources. This enabled farmers to produce abundant crops, year after year, without any concern for soil health or biology. Plants would have access to all the nitrogen they could use so harvests were greater. This soon became the norm in the agriculture industry and likewise for homeowners. Sounds like a really good deal, but therein lies the problem.
Presently it is believed that these synthetic fertilizers now total some 30% of all the nitrates existing in ecosystems of developed nations that rely on petrochemical based agriculture. That may not seem too bad until you consider that nitrogen is a component in proteins and the nucleic acids of all living things, and nitrates are in the by-products (manures, dead tissues) of all these creatures. Now we are talking one heckuva lot of nitrate.
This nitrate overload is simply too much to be assimilated by plants, bacteria, or other natural users of N. Therefore it winds up in groundwater, streams, and eventually, major rivers. As we all know, nitrates are good for plants so once this load of fertilizer hits the Gulf, it grows algae (a plant) in excessive amounts. One specific type, known as blue-green algae, robs sunlight and nutrients from competing plants. As the algae decompose they consume all the available oxygen which kills all the oxygen breathers and that creates the dead zone. The scientific term for this is “eutrophication” resulting in “hypoxia.”
The news reports generally lay the blame on the agriculture industry and the corn grower in particular. There is no argument that conventional corn crops are heavily fertilized, but that is not the only human input that contributes to the problem. For one thing, the nitrate runoff from your average neighborhood can run seven to ten times higher than the same amount of farm land. The farmer is frugal, being driven by slim profit margins, while the homeowner is mainly interested in green grass. There is little or no economic incentive for the average suburbanite. In fact, the cheaper lawn fertilizers available for the home landscape are the more damaging, high nitrogen, synthetic products.
I hope that what you have gained from this, so far, is the idea that simply switching to organic fertilizers (that by their very nature have lower N values) would significantly reduce leftover nitrates. Remember rain with lightning is only 4% N. What grows plants better than natural rainfall?
Buy organic foods whenever and wherever you can. This sends the appropriate message to producers, plus you will reap the health benefits. Unfortunately, this is only part of the solution. There is much, much more to the story. The next installment of “An Inconvenient Dead Zone” will appear next month. Until then, you may want to do some research. I “googled” dead zones and got 92,800 (plus) hits…..No kidding.

In the last month’s article I attempted to explain the nitrate issue regarding the dead zone occurring at the mouth of the Mississippi and other major river systems. As fertilizer, nitrates are described as the N in NPK. Those are the three numbers that appear on each and every product being sold as fertilizer. Current research has it that some 51% of the nitrates entering the Gulf of Mexico can be traced to the typically high nitrogen levels present in synthetic fertilizers.
The other 49% of the nitrate contribution comes from organic sources. Our own human waste ranks at the top of this list. Effluent from water treatment plants (sewage sludge) plus drainage from septic systems are the likely suspects. However, the runoff from inner city and suburban lawns also add to the nitrate overload. Perhaps more than most of us realize. Consider the human population of the entire Mississippi drainage.
The good news is that sewage treatment standards are monitored closely by state and federal agencies. Standards concerning effluents have risen considerably over the years. This is a very good thing. Most major cities are now recycling much of the treated water back into the system. Solid wastes present the greater challenge and concentrations of nitrate.
Septic systems have also improved over the last decade or so. Self contained aerobic systems discharge water that is useable in the home landscape. Open air lagoons also present better opportunities to recycle sewage effluents before they find their way into our water supplies. Be that as it may, all of these systems do eventually fill with solids which have to be dealt with.
In addition to human waste, there is also the waste from concentrating cattle on feedlots plus the factory production of pigs and chickens. While concentrating animals like this seems to be efficient from a production and shipping standpoint, runoff from these areas adds considerably to the nitrate problem. We have seen some producers who have built “manure barns,” and some send waste products to open lagoons while others simply throw tarps over huge piles to prevent rain from leaching the nitrates.
Manure piles that are denied oxygen and water tend to break down anaerobically. This creates methane which is also a contributing greenhouse gas. Now you would think local farmers would love to have all this manure to use as fertilizer. Truth is that the meat and dairy producers have gotten so big that once the locals have gathered all they want there is still millions of tons of manure that go unused. Shipping the waste to outlying farms gets expensive and time consuming. Most farmers find synthetic fertilizers more cost effective. This system merely exchanges the nitrate problem for a methane problem while leaving mountains of good compostable material wasted.
Speaking of greenhouse gases, nitrogen products also add to the mix. As a result of the feedlots, fertilizers, and apparently any exhaust from almost all heat sources, including auto exhaust, nitrous oxide (N2O, also called “laughing gas”) and ammonia (NH3) have increased dramatically. While not near as abundant as carbon dioxide (CO2), nitrous oxide is said to be near 300 times more potent in breaking down the protective ozone layer. Ammonia is a major culprit of acid rain. These are distressing facts, to be sure, but all the more reason to reduce the manufacture of nitrates through heat processes.
Because nitrates are readily absorbed in water, they do present some immediate local threats to human health. Nitrates in water supplies cause methemoglobinemia or “blue baby syndrome,” miscarriages, and thyroid cancer in women. Nitrates are reported according to EPA ruling and limits are set at ten ppm (parts per million) or less as allowable for drinking. However, some health studies indicate that health concerns may arise with nitrate levels as low as 5 ppm. If you are drinking well water you should definitely have it checked periodically.
Nitrates can be removed from drinking water by expensive treatment plants. This is a typical reaction to seek technology to cure a problem rather than address the problem itself.
In the 92,800 some odd hits I got from googling “nitrates, dead zone, water supplies” it was obvious that there is apparently plenty of people monitoring the nitrate flow and measuring the size of the dead zone in the Gulf of Mexico. In the material I have read so far, there are plenty of facts and figures that point the finger at the various sources of the nitrate pollution problem but very few solutions offered.
One of the biggest problems I perceive from all this is that the guys that crunch the numbers to regale us with these facts and possible alternatives is that they seem to insist on measuring crop production in terms of N. In other words, so many pounds of nitrogen per acre result in a measureable amount of productivity and that is that. What is missing in these narrowly focused studies are all the other nutrients and elements, soil characteristics, and biological organisms that also enter in to the equation. For instance, humus from organic matter can hold (or sequester) nitrates in plant useable form. Instead, the numbers people are merely seeking maximum production using less N.
If you look at the flow chart of the nitrogen cycle you will note there are five different species of bacteria that come into play in converting N into useable forms that cycle through the soil, plants, and animals, then return once again as an inert harmless gas in our atmosphere. This is where the solution will be. Just as with the carbon cycle we find that our human activity places too much nitrate and other forms of N in the wrong places. Now we have a problem.
Just what is being done? What are the solutions being offered? We’ll have a go at some answers in part three. Until then, don’t forget that you and I can do our part by using natural fertilizers. Buy organic produce and range fed meats. We hear a lot about our “carbon footprint.” The other footprint is nitrate. Do some research on your own. Knowledge is the key to solutions that work.


Part 3
In the first two parts of this series I shared what I have learned from doing an internet search of “nitrates, dead zones, water supplies.” This search resulted in some 92,800 plus references to the subject. I sampled a few articles, reports, and opinions plus did some related research on nitrogen (N) recommendations concerning corn production. From this sampling I developed an overview of the situation that contained far too much information for me to do justice in just one article. If you missed the previous articles you may check your local distributors for back issues or go to then click on the LNF magazine button to find current and archived issues. Failing that, the entire series will eventually appear on my own website:
I have been accused many times of attempting to over-simplify complex issues, and this is a very complex problem. Be that as it may, I find simple solutions do work best. My main concern is to raise public awareness. What follows are some of my thoughts and observations on the matter.
From all I read, it is obvious that the corn industry has been targeted as the major culprit in causing the hypoxia, or dead zone that enters the Gulf of Mexico via the Mississippi River. This is in spite of the fact that estimates indicate that unused nitrates from fertilizer compose about 51% of the total nitrate causing the dead zone, the other 49% being attributed to human and animal manures plus other sources.
There is major concern over the fact that our government, in an effort to promote alternative energy, is subsidizing an increase in corn to be fermented into gasohol. This will of course, exacerbate the problem unless nitrate leaching is reduced in the Corn Belt. Are we trading profit in the Corn Belt for reduced fisheries in the Gulf? Sure looks that way…….
Kudos to Des Moines, Iowa, for constructing the largest nitrate removal facility in the country. Although this was done mainly to reduce nitrates in the local water supply it is, nonetheless, one of the few attempts at actually solving the nitrate problem. How many more of these facilities exist or how many it would take to significantly reduce nitrates in the Mississippi I haven’t a clue. What pollutants such as carbon emissions or other greenhouse gases are produced by these nitrate removal plants? I don’t know that either. Furthermore, this high tech solution was developed so we can continue to use high nitrogen fertilizers. A “bandaid” solution, if you will.
Another solution was offered in one study that suggested that adding phosphorous to reduce the algae and help the dead zone recover. However, that was immediately countered by other scientists who warned that high amounts of phosphorous may actually make matters worse. Little else was offered as far as actually solving the problem. In fact, many of the myriad organizations that are measuring and monitoring the situation are looking for the government (EPA?) to step up and do something about dead zones.
My good friend Fred Hall, current Texas Agrilife Extension agent in Wichita County, shared a recent study that was a co-operative effort of several leading universities in different states that produce corn. Sure enough, that study was aimed at using less N to produce the same amount of corn and thereby realizing better profit. The fact that nitrate leaching from corn fields is likely (likely?) contributing to groundwater pollution plus the hypoxia (dead zone) in the Gulf of Mexico was mentioned, but only in that fashion. This study was published in 2003 whereas the dead zone had become apparent roughly a decade prior to that.
Using crop rotation (soybeans) and recycling organic matter from the previous year’s corn stalks (and/or soybean stalks) were mentioned as natural sources of N. These sources were considered highly variable depending on the presence of decomposing bacteria and rainfall. Additions of manure were considered as a much more reliable source of organic N. However, these studies indicated that additional fertilizers (110 to 125 lbs. N per acre) are still needed to achieve a profitable yield of around 200 bushels per acre.
The entire study was aimed at realizing the “economic optimum nitrogen rate” (EONR) with the conclusion being that present day farmers may be wasting fertilizer dollars through over-application. There was no discussion of synthetic versus organic fertilizers. Also missing was any discussion of the thirteen other essential elements and minerals that are factors in corn production as well as techniques to build and maintain healthy microbe populations (although the term “environmental stewardship” was used). According to the study, growing corn without additional fertilizer is just not feasible in meeting current market demands.
Fred Hall is a third generation corn grower. He chooses to rotate corn with alfalfa and soy beans (both nitrogen fixing legumes) and even double cropping alfalfa with corn. Cow manure is Fred’s choice to replace N that is lost to crop harvesting. Fred does not enjoy the production that some of his synthetic nitrogen using neighbors harvest, but he also does not have the input costs of the high production guys. Fred figures his input costs to be around 30% less on average, so he can stay profitable on lower production. Add to this the fact that Fred’s organic corn also fetches a higher price at the market so what we have here is a modern farmer that is successful and sustainable.
As far as the problem in the Gulf, Fred’s nitrate leaching is undoubtedly a fraction of the high nitrogen, maximum production farms. Fred’s living soil is full of all of the bacteria species that break down organic matter, convert nitrates into plant useable ammonium (NH4), and denitrifying bacteria that return nitrates back into harmless nitrogen gas (N2). Remember our flow chart shows different bacteria species at each stage of the nitrogen cycle. It is debatable if these discreet bacteria exist in adequate numbers in soils that are inherently low in humus due to constant tillage and the routine application of synthetic fertilizers. In fact, I wonder if the proper array of microbes can even exist at all with the high production farming practices.
It is my sincere hope that more farmers consider using organic methods. Right now, there are very good indications that they will, but we cannot expect this to happen overnight. I see farmers like Fred Hall as part of the solution to many problems we are faced with today. The dead zone in the Gulf would, at the very least, be significantly reduced by organic farming.
Since corn production was the favorite target in every bit of the published material concerning the dead zone in the Gulf, I have devoted this segment of “An Inconvenient Dead Zone” to that subject. I feel like I have gathered enough information on corn to write a book even though I admittedly knew very little about it in the beginning.
So what about our agriculture here in Texas, where we don’t grow so much corn? The existing dead zone does impact our Texas fisheries. Due to the fact that all the runoff in this state winds up in the Gulf we should look to the Mississippi as being a warning as to what may happen to the Trinity, the Brazos, the Rio Grande, and any other river system in our state.
Next month I will share my final conclusions on the subject. Until then, do some research on your own to draw your own conclusions. Support your local farmers and live naturally to the extent you can.
Apologies to Al Gore once again, but I thought this a good title due to the similarities to the carbon cycle. Nitrogen, like carbon, also has a natural cycle that has served the biosphere for millions of years until our human activities upset the balance. Unlike carbon, nitrogen is an inert, harmless gas. There are no plants or animals that breath nitrogen, but all living things do utilize nitrogen in production of proteins and nucleic acids (RNA, DNA).
Nitrogen combines with other elements in these useable or reactive forms. Carbon products are not the only contributor to greenhouse gases. As I explained in the preceding articles, combined nitrogen (ammonia, nitrous oxide) and nitrogen by-products (methane) also contribute to global warming.
The dead zone that occurs where the Mississippi drains into the Gulf of Mexico, presently covering thousands of square miles, is directly related to nitrates from fertilizers and animal manures. In a nutshell, it is highly apparent that we have not done a very good job of managing the use of fertilizers, animal manures, and our own sewage.
Considering that human and animal wastes are in fact effective fertilizers, it seems one part of the solution would be to utilize these resources to cut back, or replace entirely the popular high N (high nitrate) synthetic fertilizers being used today. Wichita Falls has a city operated composting program that utilizes our sewage sludge mixed with yard waste and industrial organic by-products. Now if we could manage to get all the manure generated by our feedlot and dairy operations distributed then get other cities and states to follow suit, we would effectively solve that part of the nitrate problem.
Of course there is the drawback that we have built our agriculture industry to rely on synthetic fertilizers. We have an entire generation of farmers, equipment, and decades of applied science that supports the reliance on synthetic N. Then there is also that nagging issue of production. There is no argument that high N fertilizers do increase production rates. The real issue is, are we willing, as an informed and advanced society, to continue to seek bumper crops at the loss of coastal fisheries, not to mention human health and wildlife in general?
In my last article I used the example of our Texas Agrilife Extension agent, Fred Hall, who still owns the family farm up in Iowa. Fred grows corn organically and apparently he has been profitable. Having Fred’s firsthand knowledge of the corn issue has proven extremely valuable. Although there were references to organics in some of my reading, most were of the opinion that switching to a organics was not going to solve the problem. However, using natural N sources (legumes, nitrogen fixing bacteria, manures) will reduce nitrate leaching however you want to do the numbers. This is irrefutable.
There are also a good number of pelletized, crushed, and liquid organic fertilizers on the market that could be used with modern farm equipment. So far I have not heard much about these being utilized or even considered by large scale producers. As owner of a retail organic nursery I can say with confidence that these natural fertilizers are being used with excellent results by a good number of homeowners. Couldn’t the agriculture industry with all the accompanying university based science have similar success? I see no reason to think they could not.
Here is a true paradox with the nitrate finger pointing going mainly to the Corn Belt. Some of the more popular organic lawn fertilizers to hit the market in the past 15 or 20 years are actually made from corn. The University of Iowa has led the research and at least one patent is held by the scientist (Dr. Christiansen) who conducted the field trials. So, here we have a crop that relies on copious fertilizer being produced with increasing amounts going to make…….well, fertilizer? As my friend John Krause would say, “I don’t get it!” Al Gore might respond with his classic ……”H,mmmm.”
As far as acreage for production is concerned, I do recognize that to produce the same volume of corn we harvest using the high N synthetic fertilizers, our production acreage would basically have to be doubled if all the farms went organic. I would think this might make the corn lobby in Washington DC pretty happy? Perhaps as an alternative we could find ways to get by with less corn altogether?
One way would be to plant crops (other than corn) for bio-fuels. I have read some very good statistics on studies from the University of Tulsa that suggest that our native switchgrass (panicum virgatum) is a viable alternative to ethanol from corn. Switchgrass is native as far north as Canada and is common throughout much of the United States. Switchgrass is a perennial that returns from roots each Spring so it would not have to be replanted like corn. Like corn, switchgrass can be baled to pull double duty as hay for livestock plus supply the bio-fuel industry. Switchgrass can be grown in the Corn Belt with little or no fertilizer input. Less fertilizer means less nitrate and ultimately less dead zone. Main problem is that switchgrass does not have a powerful lobby in Washington; corn does.
Perhaps our government should use that corn subsidy money for ethanol production elsewhere. Maybe they should subsidize manure hauling? As stated, large feedlots, chicken farms, hog farms, etc. also contribute to the nitrate problem. Maybe we should develop laws that make it mandatory that animal wastes be trucked to the nearest farm fields or composting operations.
Maybe we should have incentives for nitrate reduction as we are beginning to see with the carbon issue. High nitrogen fertilizers (ammonium nitrate, ammonium sulphate, anhydrous ammonia) can be very damaging to a great many soil dwelling creatures, not the least of which is earthworms. In my opinion, anhydrous ammonia (very popular in large acreage production) should be banned altogether. This is an extremely volatile substance that has caused respiratory illness, blindness, and instant death to humans who are exposed. This chemical concoction was originally used during World War II to compact soils in creating runways for air traffic. Compaction was quickly accomplished by killing off all soil dwelling organisms. What farmer really wants soil compaction? Taking anhydrous ammonia off the market would also have the side effect of reducing illegal drugs. It is one of the ingredients in home brewed methamphetamine. Zero anhydrous ammonia equates to less soil compaction, less nitrate pollution, and less drugs to boot?……Sounds good to me!
Aside from the dead zones, nitrate pollution also compromises local water resources. This is especially problematic with underground water supplies. Well water generally comes from deep reserves beneath the level of the denitrifying bacteria or other living organisms that could utilize excess nitrate. Look once again at the flow chart of our nitrogen cycle to see how important it is to follow Nature’s plan. I am confident that future farmers will be “managing microbes” instead of trying to juggle fertilizers to achieve the EONR (economic optimum nitrogen rate).
In conclusion, I believe it is irrefutable that we are using too much N and wasting far too much of what we apply. These ideas I have offered may seem over-simplified, but I am confident they would at the very least reduce the dead zone and return that part of the Gulf into the valuable food source it once was. Seafood does not have to be planted and tended like other food sources. It only requires a suitable environment and someone to harvest. I hope you will join me in being part of the solution rather than adding to the problem. I welcome your comments. Email me at, or better yet, maybe we can get together one day, throw some fresh shrimp on the grill, and have a good discussion.

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