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Nutrient Recycling — What Bugs Me!

We, as humans, are consumed by the desire to continually increase efficiency. Why? We need GPS on our tractors; we need the newest and greatest wonder product that will make us more productive. Sometimes, I think we just need to step back, and let Mother Nature teach us that efficiency is not getting us where we want to go. Take, for example, nutrient recycling. Did you know about 80 per cent of the nutrients consumed by a cow comes out the other end? She just drops it on the ground. Why would Mother Nature make such an inefficient critter? If it was up to man to design a cow, I just bet we would make sure she was 97 per cent efficient. So why is Mother Nature so wasteful? Maybe it is because it is not for the benefit of the cow?

The ruminant animal was designed for environments with a dormant season. By that I mean an extended dry season or a winter season that is unfavourable to the soil organisms. In a rainforest, the soil is never dormant and therefore is always full of biological life that is able to break down plant matter. The ruminant was placed in dormant-season environments to give the decomposers an environment they can live and work in… the rumen. Mother Nature’s decomposers are able to breakdown plant matter. That is crucial for nutrient recycling. The ruminant is therefore only a part of the whole picture. Our problem is we see our cattle as the centre of our operations instead of as a tool in the bigger picture. I use to think that I was a cattle farmer, but I soon realized that if I can take care of the grass, then that takes care of the cow. So I became a grass farmer. I then realized that when I take care of the soil it will take care of the grass, which in turn takes care of the cow. So I became a dirt farmer, and maybe even a bug farmer.

This waste product that the cow puts on the ground for us is full of nutrients that Mother Nature intends to recycle. Now that we have that figured out, we can just sit back and let the cow spread our fertilizer? Wrong. Just because we have the manure, does not mean we get the nutrients. Those old cow patties from last year that are still out in your pasture are not decomposing. They are weathering. Nutrients are leaching out into our water systems and volatizing off into the air. And for all you farmers that deal with cow patties by running around with the harrows, congratulations, you are speeding up the leaching and volitization processes by increasing the surface area of the manure. But yes, they are gone, just not where we need them.

What we need now is some way to decompose this manure even farther to make the nutrients available to the plants. We need soil organisms to consume it — bacteria, yeast, fungi, nematodes, earthworms, dung beetles. I call them my underground army of workers. They will work harder for you than your best hired man. Just give them an environment that they can survive in with plenty of organic matter to eat and lots of soil moisture. They will do the rest.

I also have to make sure that my management practices do not harm them or alter the environment and reduce their populations. I would like my hired hands to multiply in numbers, to decompose the manure and residue that is left on the soil surface and physically eat it. I want them to use the nutrients to build up their own bodies. Then I want them to physically take the nutrients below the soil surface and die to make the nutrients available to the plants again, completing the circle of life. Anybody want to come work for me? It just so happens that I have a billion more workers eager to go to work again the next day. This is how I can get the manure to decompose and the litter or trash to break down into usable nutrients for the plants.

Soil microbes form symbiotic relationships with plants to benefit not only the plant and the microbe, but also assist with nutrient recycling. In return for food, they provide nutrients to the plant. Our best example, of course, is microbes

that pull nitrogen from the air in a symbiotic relationship with legumes. The air we breathe is 78 per cent nitrogen. I can’t imagine myself ever buying nitrogen when I can just have my employees get it for me for free. Need I say more?

There are bugs in the soil that help with overall plant health. They are busy releasing nutrients when needed, controlling pests and disease and providing the roots with all sorts of beneficial interactions. As I said, Mother Nature has this all figured out. When they break down litter from the soil surface and decaying roots the organisms are building humus in the soil. This in turn generates water-holding capacity. Humus can hold up to nine times its weight in water. Dead soil has a thickening thatch layer that does not break down and can inhibit water infiltration. A healthy soil absorbs water like a sponge. Did you know that anything that comes out the back end of an earthworm is pH neutral? So soil organisms can also buffer soil pH.

If these soil bugs are my underground army of workers, who are they at war with? It’s us, of course, and the management practices on our ranches that negatively affect soil microbe populations? Do I need to explain the detrimental effect of chemicals on soil organisms? The labels always recommend I wear gloves and a mask when handling this stuff. And I weigh 160 pounds wet, a lot more than a dung beetle or bacteria.

Tillage not only causes faster evaporation, and removes the thatch layer that shelters my workers, it also disturbs their environment and that can be fatal. There are two basic types of bacteria, anaerobic and aerobic. One does not like oxygen and one does. Tillage turns over the soil and may put my bugs where they don’t want to be.

The more acidic soil becomes, the more it negatively affects the natural soil life. I recall having a debate with my fertilizer professor years ago about the H+ ion that is released every time a granule of nitrogen fertilizer breaks down. I asked him “How do you stop the soil from becoming more acidic when fertilizing?” He said you could lime it but it is very expensive. I asked him again, “How do you stop it?” He said you could put it back into grass and that would slow it down. I asked him again, “How do you stop it?” He had no answer. I have figured out the answer on my own and it was pretty obvious once I saw it. I broadcast legume seeds instead of fertilizer. Dilemma solved.

So how does all this relate back to our poor old cow? She is a big part of ranching but she is only a tool in our operation. Nutrient recycling only works if you recycle it! What a concept. In most agricultural practices most of the nutrients from the soil are exported. Only in a grazing operation can we effectively recycle the nutrients. If the land is healthy and our nutrient cycle is working, we only export 20 per cent of the nutrients from the soil. When you harvest a crop you may remove up to 90 per cent. Which is cheaper to replace, 90 per cent or 20 per cent? In my operation, I have figured out how to use the 90 per cent of the nutrients someone else exports out of their soil, to replace the 20 per cent the cows remove from my land. I like it! And I have someone else pay me to do it. Next time you implement a management practice on your operation, ask yourself, “How will this affect my army of underground workers?”

Steve Kenyon runs Greener Pastures Grazing Management in Busby, Alta.,www.greenerpasturesgrazing.com,(780)307-2275

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