Tuesday, April 29, 2008

Commercial Fertilizer Reformulation

I added a couple of items on commercial fertilizers today to clarify the current status of the industry. Yesterday’s article on the practicality of using elemental carbon from coal got me thinking of the commercial fertilizer industry itself and the realization that at the least a transition to carbon based fertilizers may be the revolution that the industry has been looking for.

I quote the following short item which clearly outlines the problems every farmer knows.

Commercial fertilizer, especially nitrogen, is easily washed below the level of the plant's root system through the leaching of rain or irrigation. An application which is too heavy or too close to the roots of the plants may cause "burning" (actually a process of desiccation by the chemical salts in the fertilizer). As well, overly heavy applications of commercial fertilizers can build up toxic concentrations of salts in the soil, thus creating chemical imbalances. If organic materials are readily available and cheap, the expense of the commercial fertilizer should also be considered.

It has been the practice to blend the nutrient components of fertilizer with a neutral carrier that provides most of the actual weight of a fertilizer blend. This particularly applies to urea which needs to be blended and prilled. I am not so sure about potassium and phosphorus but you get the idea. Fly ash and various earths seem to be commonly used. They are all typically neutral to the overall process of fertilization.

They are all soluble salts and are obviously vulnerable to been leached out. This has been the monkey on the fertilizer industry from the very beginning.

Past work in Cuba, made an effort to abate this problem by blending with volcanic zeolites. They had measurable success. It has also been applied elsewhere in a piecemeal way due to the limited availability of zeolites.

So where are we? Powdered elemental carbon can be used in the same way as the zeolites for the same reasons. The material grabs the nutrients and holds them until a plant root is able to extract them. This is why the terra preta soils are so fertile in rain forest ecology.

The real break for the farmer is that only enough carbon is needed as a nutrient carrier, rather than the tons per acre suggested by the Amazon. The carbon will still persist and accumulate. Biochar can still be practiced as a way to better remove plant waste and sequester CO2. But today, the same sack of fertilizer is doing the same job as a sack last year. The difference is that there is a reduction in leaching and perhaps a large nutrient carryover into future crops.

Without anything other than an incremental modification to the manufacturing process and little change in the cost structure, we are suddenly implementing terra preta culture everywhere industrial farming is conducted.

The open question, that can be only resolved with multiyear field trials, is whether this is a cheaper way to deliver nutrients to our crops. We have eliminated a portion of nutrient wastage. How much we actually wasted is open and how much can now be retained is also open. The swing might totally surprise us and also steadily improve as more carbon is added to the soils.

I added this FAQ from the Canadian Fertilizer Industry which catches us up to current practice which has obviously been steadily improving. Every farmer knows that a nutrient that escapes his roots is a nutrient lost that he paid coin for. Now if we can bind all nutrients with carbon, we may be able to end nutrient loss.

This also suggests that a mature terra preta soil will simply adsorb any nutrients thrown into the mix to the long term benefit of the farmer.

It goes without saying that such a blatantly commercial product will have to go through extensive testing before it replaces the decades old protocols that are currently with us.

Fertilizer & the Environment

Is fertilizer harmful to environment?

Commercial fertilizer has become an indispensable tool in today’s high-yield farming. Its misuse, however, can damage our environment. Fortunately, advances in agricultural techniques are enabling farmers to apply soil nutrients with pinpoint accuracy, minimizing or avoiding altogether any damage to soil, water, and air.

New soil sampling and tillage methods, use of starter fertilizers, and better timing and placement of nutrients mean producers are getting more bang for the buck from fertilizer. For example, farmers today are producing one-third more corn for each pound of nitrogen they apply, compared to 20 years ago.

Commercial fertilizer is also helping to conserve land. Without it, we’d be forced to plow up parks, wildlife habitats, and parks so we could produce enough food to feed the world’s growing population. And by improving plant nutrition, fertilizers help reduce global warming. Experts estimate that American crops give off as much as 500 million tons of oxygen every year.

Wouldn’t it be better for the environment to use less fertilizer?

As a result of advances in agricultural practices, farmers have been cutting back on the amount of fertilizer they use. We’ve made great strides in gaining maximum efficiency from the amount we do apply. There’s a fine line though, between using just the right amount of fertilizer, and not replenishing the nutrients needed to keep pace with today’s high-yield farming.

Last year, farmers only replaced 75% of the phosphorus their crops removed from the soil, and just over 50% of the potassium plants used. More of both nutrients are needed, or yields will fall.

But that’s not the only problem associated with depleting nutrient reserves. An insufficient supply also saps plants’ ability to withstand harsh weather, disease, and other stresses. Nutrient-starved plants cannot maintain soil moisture, which leads to soil erosion from wind or water.

Although dry weather played a key role in the “dust bowl” conditions of the 1930s, insufficient levels of nutrients were at the root of the vicious cycle of problems that plagued Depression-era farmers. Plants could not help the soil hold enough moisture, which in turn caused increased wind erosion.

Isn’t organic farming better for the environment, since it doesn’t use fertilizer?

Most organic growers use fertilizer too. It comes from different ingredients, such as livestock manure or sewage sludge.

However, these natural fertilizers are not available in sufficient quantities to meet the demands of today’s high-yield farming, nor do they provide nutrients in the ideal balance made possible with commercial fertilizers. For example, using enough manure to provide the soil with an adequate supply of nitrogen would mean adding four to five times more potassium and phosphorus than a crop needs. So it’s easy to over- or under-fertilize in this type of farming.

As well, organic crop yields are only one-third to one-half as high as those from farms using conventional fertilizers. So we’d need to turn millions of additional acres of land over to farming, and still end up with less food.

What is runoff from fertilized land doing to our lakes and streams?

It’s true that phosphorus and nitrogen can harm water quality. Thanks to advances in agricultural techniques though, farmers are now able to precisely tailor nutrient amounts to their specific soil conditions — so nutrients are either taken up by crops or stay in the field.

The foundation and others in the fertilizer industry are committed to promoting practices that protect and enhance the environment, including use of conservation buffers. These strips of land along the edges of bodies of water are planted with permanent vegetation designed to slow runoff and soak up nutrients before they run into streams, lakes, and rivers. Studies have shown that these buffers can remove more than 50% of nutrients in runoff from farms.

1 comment:

  1. Just a quick reply after a quick read of your article, I have much to do in my garden.
    ***
    My long term plan, to build circle cities that feed ten thousand people off two thousand acres, set in the middle of a further 27 thousand acres, without fossil fuels and without artificial fertilizers, is entirely feasible, in my opinion.
    ***
    This would, of course, require all organic waste to be returned to the soil. All wet waste to be digested and all dry waste to be pyrolysed.
    ***
    No animals to be kept, they use too many resources. Wild animals in our extensive forests could be hunted or culled and used for food, but we don't need to. Veganism plus a tiny bit of vitamin B12 is all we require for healthy bodies.
    ***
    In creating biochar over thousands of years we might build biochar mountains of big lump charcoal that won't easily blow away. Very useful if we are threatened with an ice age. Just set fire to some or all these mountains as well as spreading powdered charcoal on ice to cause it to heat up and melt. End of ice age (unless there's no stopping it for some reason).

    All for now,

    Bob Howes

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