THE UNTOLD STORY OF PLANT GROWTH
We have covered a lot of ground, no pun intended, in these little essays about grasses and forages. And it has been too long since I have taken keyboard in hand. There is one topic that so far has not been mentioned and it may well be the most important topic of all and the key to growing good forages as well as any other crops.
As humans we like to try to understand things and to understand them we have a tendency to break them down into components and study the components individually. This gives us the ability to focus on the subject at hand and to examine and try to understand it thoroughly and completely. Indeed, I have done that very thing with these essays.
Given that laser like focus, with regard to soils and plant growth our scientists can tell us exactly what to add to a particular crop to make that crop achieve the desired yield goals….Champion farmers know what it takes to raise three hundred bushel per acre corn.
Why is all corn then, not three hundred bushels per acre? Simply because it is expensive to add the inputs required to grow three hundred bushel per acre corn on an enterprise wide scale. I grew up in the livestock business and I am all too familiar with the conventional wisdom and the new science of our time….I have lived it for almost sixty five years. Sometimes in a quest for production, a beneficial practice is discovered and then implemented to extremes only to rediscover the law of unintended consequences.
In my doterage I have finally to begun to question what I know and ask myself how it was done before we became so smart. How did our grandparents and great grandparents produce food and fiber in a sustainable fashion before we had chemical fertilizers and all the other inputs we use today?
Part of the answer is that many more people farmed….yields were not nearly so good and the majority of the country produced at least some of it’s own food. Everyone had a vegetable garden. People cultivated and controlled weeds with a hoe. Many back breaking hours of labor drove many people away from the farm. I know that when I joined the army it was not long before my daddy discovered the greatest invention ever…..the Vermeer Big Round Baler….Prior to that the greatest invention I had ever seen was the ability to load bales onto a wagon towed right behind the baler….This was light years better than picking hay up out of the field, then throwing it on the wagon and then jumping up to stack it and then jumping down to race to the next couple of bales.
You can only imagine my surprise when I learned that other farms had two and three people doing this work…I have always been a little slow to learn….I was the poster child for dumb and strong as an ox.
But these improvements in inputs and machinery have come at a cost. We have removed ourselves from a direct connection to the land. And with that connection and improvements in yields we have not noticed what we have lost.
To understand what we have lost sometimes we have to look at the natural world to see how Mother Nature makes things work. The power and simplicity and complexity of the natural world is awesome to behold. And if we observe we can learn.
Grazing management started by observing how nature manages grazing….Nature had vast herds of animals moving in great migrations across the landscape in response to the natural growing seasons. The prairies and savannahs existed like that for thousands of years. Humans decided to put up fences and kill off the buffalo and plow up the prairies all in the name of progress. We have continued to innovate and find new technology and new inputs to boost yields and specialize and now one farmer feeds something like 170 people per year. The number increases every year. But every farmer has to farm more land to make a living and the prices of the inputs are growing and minable resources are becoming more scarce. And farming specialization has made complementary enterprises a thing of the past for the most part. Our understanding of the management complexities and the technology increases, but our connection to the natural process diminishes.
Producers with 300 plus horse power tractors with air conditioning and computers and gps guidance and thirty feet wide implements can do a prodigious amount of work precisely, both day and night. They know every nuance of the crops they grow and how to make it the best….
But they are more disconnected from the soil than they would be comfortable with admitting.
The soil is not just dirt and chemicals and water and air. The soil is a living breathing ecological system. In a good healthy soil there are millions of life forms in a teaspoon of soil. We have tended to go for the quick fix for the crop and have neglected our soil health.
Man has tilled the soil for over five thousand years of recorded history that we know of. But only in the last 25 years have we accepted that every time we till the soil we kill the soil. Tilling and cultivation is how we controlled competitive plants. Tilling and cultivation is ingrained in us to be a part of food and crop production. But tillage and cultivation breaks down the soil structure and destroys the aggregate nature of the soil. Individual soil particles cannot support soil life. Aggregates in the soil support soil life. I think it was Dr. Laura Ingham who coined the term “Soil Food Web”. It is the most accurate term I have heard to describe a healthy soil.
A healthy soil is not just dirt. A healthy soil contains moisture. A healthy soil contains oxygen and carbon dioxide and other gasses. A healthy soil contains worms. A healthy soil contains nematodes. A healthy soil contains insects of all sizes. A healthy soil contains Bacteria. A healthy soil contains Fungi. A healthy soil contains plants and plant roots to provide the solar factory to make it all work. A healthy soil contains a diverse mixture of all these things in an intertwined biosystem that is capable of adapting and growing.
Mother nature does normally not grow monocultures. There are a few exceptions where a particular plant has evolved to deal with an environmental constraint, but given time, nature will overcome that constraint and diversity will be restored.
Every plant in nature has a role. Every plant in nature has complementary life forms that form symbiotic relationships with that plant. The most easily understood is the nitrogen fixing bacteria species that form associations with legumes and trade nitrogen fixed from the atmosphere for sugar from the plants photosynthetic process. This is easily understood because it can be seen with the naked eye by examining the nitrogen nodules on the roots of a legume. But there are thousands of such relationships between the plants and plant roots and the insect and micro biota. This is true above ground as well.
There are bacteria that live in association with the roots that have chemical activity in the soil that release nutrients such as phosphorous from the soil and make the nutrients available to the plant for uptake. Different bacteria and microphages and macrophages react with different soil nutrients and elements making them available as well.
Fungi live in close association with the finest roots of the plants and it can now be shown that the fungi form a network that actually serves to extend the reach of the roots into the soil for nutrients and transmits those nutrients back to the roots.
It is known that microscopic life acts in close association with the roots to actually act chemically to dissolve the soil in order to aid in root penetration into the soil. Both the plant and the microbiota receive benefit from this relationship. So much so that they give off chemical exudates or biological ooze, which forms a biological glue like bond between the roots and the organisms and the soil particles? These small clumps join together with other small clumps to form soil peds or small lumps of soil. In these small lumps are the spaces where water and air are present to allow for life respiration. These small lumps bond together to form larger aggregates. This produces mores spaces for water and air storage and root movement, and more life and larger microbiota. These soil aggregates are what gives structure to the soil and reduces erosion potential and allows water infiltration and good soil life habitat.
When you add another plant which brings another community of associated life, both plants and both communities benefit. So a diverse plant community provides a tremendous opportunity for the fullest extent of the underground beneficial association and development of both plant and soil health. Healthy plants nourish healthy soils which nourish healthy plants. We have a multispecies cover crop project going on in our area. Over the last few months I have pulled up enough cover crops to see the roots of different plant species intertwined. This was not just happenstance. The roots of one plant sought the biodiversity benefit of association with the roots, and the root community, of another plant and both plants benefit.
All a part of a natural cycle. All we have to do to take advantage of it, is to stop killing it by tilling it. One of my next on farm experiments is to try to grow no till vegetables in a clover sod and control competition by mowing the clover.
In the European settlement of the new world, the indigenous people taught the first settlers to plant corn beans and squash together and to put fish offal in the hole to provide nutrition. I am sure they did not know why it worked, but they lived close enough to the land to understand that it did work. The indigenous people did not have much confined livestock but the fish soon translated into using livestock manures. Ironically, many organic growers have returned to using fish oil and fish meals as fertilizers.
Nature has not changed much in those 400 years. We have developed better and more productive plants, but the plants relationship with the soil has not changed.
We are learning to improve our crop soils by the inclusion of multispecies cover crops and intensive addition of organic matter to the soil. Similarly we are learning that forage crops need to be diverse mixtures of complementary crops. Grazing animals need to be allowed to return their natural byproducts to the soil. Almost any addition of organic matter to the soil is beneficial. Natural grazing and trampling of the soil is beneficial. Plant rest is crucial…
Let me share and observation I made this year totally by accident. Several years ago I cleared a small area of less than a half acre of trees and brush with the objective of creating an improved grazing area. My method of clearing is to cut it down and harvest what I can as firewood and burn the laps and brush on site. I do not worry about stumps as they will rot out quickly enough for pasture. Many horse folks think this to be idiotic. I have a more western and practical approach. Any horse that cannot be depended on to navigate terrain safely is a danger to me as well. They need to learn to walk in the natural world. But I digress. This area over the intervening years has had lime and fertilizer and seed and manure applied but it has never amounted to much and did not have a decent stand of grass and never provided much forage. I decided to just let it be and not use it this year and actually never even walked by it during the summer. Now this area is surrounded by trees and I rationalized that the trees were taking all the nutrients and that this area would not amount to much.
In the late fall I walked through it on my way to somewhere else and could hardly walk for the thick fescue and Bermuda grass with some patches of nice clover. I determined that this would carry the bulls for a few days and let them in there. This half acre carried two yearling bulls and one mature 2200 lb bull for two weeks and I finally pulled them off to prevent damaging the fescue. I still had about 8 inch high grass in the lot. All it took was rest and time to allow those plants to establish and put down roots and develop the soil environmental associations. As is often my habit I broadcast some cover crop seed on the area and shut the poly wire gate. I am anxious to see what it looks like in spring. This summer I will manage graze it in about four strips and rest another field.
Following the rules of nature should be the most important element. To do that sometimes we have to overcome our conventional wisdom and learn through observation.