Grazing in Michiana
I may have mentioned in previous articles that chemistry is not one of my personal strengths. Anything that transcends beyond basic mathematics, addition, subtraction, multiplication and division and very basic algebra doesn't really click in my brain very well. I wish it did, but at age 60, I have about decided that it's a little late to develop new skills.
I am, therefore relieved, that others find chemistry an easier topic to comprehend than I do. The understanding of how chemicals interact in nature is crucial to a whole host of other topics like botany and a realization of how plants need nutrients—another name for chemicals—to complete photosynthesis, thrive and grow. In a world with an ever-increasing population to feed, it is important that farmers know the basics of fertility to meet the world's need for food.
When I ask a group of school students what it takes to make gardens grow well, I get a lot of different answers, but some brave soul in the class usually comes up with the word "manure" early in the conversation. In front of elementary and junior high aged students, this contribution usually is met with red faces, giggles and embarrassment. Once we get passed all of that, I have to agree. Even in days hundreds or even thousands of years ago, man discovered that the introduction of manure and other organic matter to the soil increased crop vigor and yield.
Looking into this matter a bit, the application of manure to soil used to grow crops or grazing forages benefits productivity in several ways. Manure should be considered a resource, not a waste product. This is a particularly important fact for a rotational grazing farmer to consider.
Soils benefit from manure application by improving soil structure and texture, increasing productivity through the enhancement of biological activity in the soil; the introduction of major plant nutrient requirements like nitrogen, phosphorus and "potash" or potash, and the spreading of manure enhances and speeds up the breakdown of organic matter in the soil, improving availability to plants of nutrients necessary to plant growth.
Manure affects other important soil qualities as well, including water retention (or in some cases, drainage). Not only does manure contain macronutrients, the "N-P-K" already mentioned, but can also contain micronutrients as well, chemicals like calcium, magnesium, zinc and copper.
Getting back to my original topic of chemistry, I want to mention a concern that has been often brought to my attention over the years. I have a "conscience" that whispers in my ear at almost every pasture walk that I have attended over the last 20 years. I won't give you his name, but chemistry—especially the chemistry of plant science—is a special interest of his. He has observed the rise over the last two decades in enthusiasm for rotational grazing and also for organic farming practices as well.
He has observed that many organic farmers rely heavily upon the use of manure application for their fertility programs on their farms. In some cases, manure application is the only method used on organic farms to address soil fertility issues. With his interest in plant and soil chemistry, and especially in his emphasis on the importance of soil micronutrients, he points out that manure application is simply not enough. My conscience, as I am calling him, maintains that while manure application is good, it alone cannot complete a fertility program on any given farm forever.
I have thought about this issue for a long time. As I started out by saying, my understanding of chemistry is not that well developed. But as I read on topics concerning the importance of micronutrients in the soil; elements like sulfur, magnesium, manganese, boron, calcium, sodium and so on, I will have to agree that as milk is sold off the farm, as hay or row crops are sold off the farm, eventually, manure application alone is not going to replace some of these minor but critical elements.
Maybe you are like me. Soil tests are not cheap, and if the piece of paper you get back from your favorite farm lab doesn't make sense or change anything about how you are managing your operation, it probably seems like a waste of money. A better approach than ditching your regular soil tests, however, lies in paying not only for the soil tests themselves, but also paying for expert interpretation of the results. If you yourself are not a chemistry whiz, hire someone you trust who is! In the long run, good nutrient management on the farm will pay.