Welcome to Book of the Week – a weekly feature offering you a glimpse between the pages of an Acres U.S.A. published title.
This week’s Book of the Week feature is Advancing Biological Farming, by Gary Zimmer.
From Chapter 3: The Six Rules of Biological Farming
You might wonder how I can work with so many different kinds of crops in so many different areas of the world when soil types and crop nutrient requirements vary so much. Without knowing anything about the crop being grown, how can I help the farmer? What I do is look at a soil test and mineralize the soils based on that soil test. It’s true that crops and soils vary, but there are some things that are the same no matter where you farm or what you grow. All crops need a variety of minerals, and all crops need soil biology to grow. I can make recommendations for many different crops because I take soil tests and I ask the right questions. Important questions like, what are you doing now? What’s working? Are your soils healthy and mineralized?
The Six Rules of Biological Farming are guidelines I came up with that work for all biological farmers around the globe. They will move you toward your goal of being a successful biological farmer no matter where you live or what you grow.
The Six Rules of Biological Farming
Rule #1: Test and balance your soils and in addition feed the crop a balanced supplemented diet. This rule is about understanding your soil’s baseline mineral levels, and adding soil correctives to improve that baseline.
Before testing your farm soil, there are a few things about soil testing you should be aware of. First, different soil test labs give different results. Though different labs may conduct the same tests, slight variations in equipment and protocol will affect the results. There are two reasons for Always using the same lab: 1) so that soil tests from the same field can be compared from year to year and 2) so that recommendations for soil correctives are consistent.
Second, soil sampling isn’t an exact science. Not only is a small sample of soil supposed to represent an entire field, but what is measured from that sample is only what can be extracted in a lab. What the plant can extract from the soil may be different. That’s why it’s important to also conduct tissue tests or feed tests in addition to soil tests as a way to gather more clues about what nutrients the plant is able to extract from the soil.
Third, soil tests measure soil minerals by extracting them from the sample with a mild acid. Your soil test is limited to measuring what can be extracted by this methodology. Soil tests do not measure biology, structure, or even all of the minerals found in the soil. There are other important factors of soil health that will affect how your soil performs, such as what plants have been grown there, what inputs have been used over the years, how well roots are able to develop, how many earthworms are present, and more. Soil testing just does not tell the whole story!
Another factor to consider is pH. Soil tests are designed to work within a range of pH, and if the pH is high or low, the soil test won’t be accurate. If your soil falls into one of these two extremes, plant tissue tests or feed tests are needed to get a better idea of what minerals are available in your soil.
Recognizing that soil testing has its limitations, it’s still important to take soil samples every two to five years and use that information to help you improve your soil, and spend your fertilizer dollars where they are needed. A soil test provides you with an estimate of nutrient levels in your soil, and tells you whether the levels are sufficient, in excess or deficient. It’s also very important to look at all of the macronutrients and micronutrients, not just NPK. A good soil test includes measurements of phosphorus, potassium, calcium, magnesium, sulfur, zinc, manganese, iron (Fe), copper and boron, as well as organic matter, CEC (cation exchange capacity) and pH.
The first thing to look at on a soil report is what soil correctives are needed. Determining what soil correctives to add is simple. Whatever nutrients are lacking I want to add. Whatever I have enough of, I don’t add. On my farm the soils are high in magnesium and low in calcium, so I need to apply calcium but not magnesium. Dolomitic limestone (calcium magnesium carbonate) would be the wrong choice for my farm because I don’t need more magnesium. Gypsum (calcium sulfate) or high calcium limestone (calcium carbonate) would be much better choices.
Keep in mind that you need to deal with excesses as well as deficiencies. There are interactions between minerals in the soil, and a mineral in excess can cause as many problems as a mineral that is deficient. In order to provide your crop with a balanced diet, you need to be sure to keep all mineral levels in the soil in balance with each other.
The second thing to look at on your soil report is the crop fertilizer. This is a completely balanced fertilizer for the crop that you are growing that provides nutrients above and beyond what the soil can provide. Even if there is a good balance of all nutrients in the soil, a crop fertilizer is still needed each year to make up for some of the nutrients the crop will remove and to provide trace elements like sulfur and boron that don’t build up in the soil.
Up next: Rule #2: Use fertilizers that do the least damage to soil life and plant roots.
About the Author:
Gary Zimmer is an organic dairy farmer, an accomplished speaker, a sought-after farm consultant and president of Midwestern BioAg, a biological farming products and services company. He is also the author of The Biological Farmer, the prequel to Advancing Biological Farming.
More By This Author:
Be sure to check out the Gary Zimmer audio collection for a complete selection of his previous Eco-Ag Conference seminars!
Titles of Similar Interest:
- Hands-On Agronomy, by Neal Kinsey and Charles Walters
- The Farm as Eco-system, by Jerry Brunetti
- The Art of Balancing Soil Nutrients, by William McKibben