Few things are better than eating produce picked fresh from your own garden. The flavor, the freshness, and knowing this is the culmination of your hard work all serenade your mind with an ecstatic feeling. Now we can make this one step better. We can grow a beautiful garden or field without the use of synthetic fertilizers or pesticides and not have to worry about the associated health and environmental issues. By harnessing the powers of natural systems- the soil, biology, and plants, along with our management, we can easily achieve a bountiful harvest.
Understanding the soil and its biology is a lot like reading a book that doesn’t have an ending. We don’t know everything or anywhere close to it, but we’re learning a lot. It is essential to view the soil as a metropolis. Everything has its place and time, its needs, its wants. If a disruption occurs, others fill in without problem or the voids created by the disruption can cause a huge ripple effect. The soil acts in a similar fashion. The soil system can overcome stress very well in general. It is when the soil is assaulted with unrecognizable stresses- namely synthetic compounds- that it becomes disoriented. Harnessing and understanding the workings of this system is our job without corrupting it with unnatural compounds.
What makes soil? First and foremost, soil is not dirt. Do not treat your soils like dirt or the favor will be reciprocated. Soil is a living system. Dirt is soil without life. Soil is comprised of numerous groups of micro and macro organisms. Bacteria, fungi, and protozoa are bottom on the soil food pyramid. They eat first. The larger organisms- nematodes, arthropods, and earthworms- generally eat later in the cycle and breakdown larger particles. It is the symbiotic relationships that make this soil. Soil is dirt and bunch of biology.
What makes good soil? Let’s remember how soil is developed in a simple thought. Wind, water, and biology broke down outer layers of rock, these parts accumulated, simple fungi or plants grew and died, left their remains, more complex organisms grew from this and died leaving their residue, and over time other biology flourished within. Soon enough, this rock, accumulating residue (organic matter), and biology formed the soil system- further breaking down rock particles and accumulating more organic matter. The rock we started with will vary in mineral content based on geology and geography. The mineral composition of the base rock will determine what plant and soil life will flourish in that location. We need to understand this later for our soil amending program. The other half, the better half, of good soil is a vibrant soil ecosystem. We want diverse microbiology ready and willing to help our growing system. We want a whole bunch of earthworms in our soil for residue decomposition and nutrient cycling. We want a live soil! Good soil is balanced dirt plus a whole bunch of good biology.
As organic growers our ultimate objective is using and maintaining these systems for soil health, plant health, and human health. We have several management techniques and tools to achieve these goals.
- We feed our soil- incorporate residues, compost, manures, and green manures (and maybe some extras) into the aerobic zone of the soil.
- We add minerals to our soil- provide needed nutrients to the soil and plants.
- We rotate our planting- feed all the soil bugs and break disease cycles
- We manage weeds, insects or disease holistically
- We perpetually learn we can never know too much and its part of the fun
We feed our soil. We understand the complexities of the soil system and the need to feed all of the components. This is an art more than a science so we vary our amendments. The easiest amendment is the residue left from our harvested crop. We give back to the soil what we didn’t harvest, but as with all amendments, we keep these materials in the aerobic zone-where the soil is alive and breathing. We add manure; Mother Nature’s product at the beginning and end of plant growth. Nature wants to recycle materials continually and manure is part of this system. A lot of the nutrients in manure are very soluble so don’t apply too much. Depending on our rotation of planting and time available, cover crops are beneficial. It may be hard to see a nice stand of grass or legume worked into the soil, but the soil will love it. The carbon and other minerals of the plant’s luscious growth are easy to digest for the soil. Green manure decomposing also provides a nice steady release of nutrients for the next growing plant. Depending on conditions, we may choose to use some extra products to feed the soil such as aerated compost tea, fish hydrosylate, molasses, sugar, soil microbe inoculants, and others. These are tools to feed our soils.
One of the best tools for the feeding the soil is compost. Let’s remember soil organic matter, old residues. There are four categories of organic matter in our soils- live organic matter, fresh residue, decomposing residue, and fully decomposed residues (humus). Humus has innumerable benefits to the soil and plants. Finished compost is humus. The beauty of compost is we can take fresh manure and/or organic matter, balance the carbon to nitrogen levels, turn the compost pile as needed, and end up with humus quicker than it would occur in the soil. In addition, we reduce the total amount of material to haul or apply compared to the raw materials. The biology of the compost is another benefit as a soil amendment by inoculating the soil with more good biology. We can also use our compost piles to break loose some minerals by adding a small amount of rock minerals to the working compost. The compost process can also kill weed seeds provided correct compost temperatures are met. Providing organic matter, reducing amount of raw material to haul, good biology, weed free matter, available minerals, easy to apply, and soil friendly are just a few of the benefits of compost.
Another tactic employed in working with the soil system is to balance the minerals of the soil. The plants and soil biology have needs for minerals. We must balance and add minerals according to these needs. The best way to know what to do is to take soil tests. Test for all the major and micro nutrients- phosphorus, potassium, calcium, magnesium, sulfur, boron, zinc, copper, iron, etc. Use a reputable soil lab that can provide recommendations of desired levels for your area and soils. This report will tell you where you’re at and what direction you need to go with your fertilization program. We will want to apply the needed nutrients and not add more of what we don’t need. Our end goal is to grow a healthy, nutritious crop, not to just make a perfect soil test. Knowing where our soil minerals are at is an important step.
Now we need to fertilize our soil and crop. Our soil test and recommendations tell us what to do; now we do it. Our choices as organic farmers are limited to organically approved materials. The products available are non-acid treated and naturally mined minerals. Some of the common available soil amendments include soft rock phosphate, sul-po-mag, lime (dolomite and calcite), potassium sulfate, magnesium sulfate, borate, zinc sulfate, and copper sulfate. The application rate, form, and how they are derived is very important to being an allowed material, some of these materials are restricted and may not be allowed by certifiers. These sources are not very high in soluble nutrients so you need good active soil biology to break down them into available forms. Humates or humic acid may help make rock powder nutrients more available when added as part of the fertilizer. Getting the soil and crops fertilized for these main nutrients is important.
The one nutrient I didn’t mention was nitrogen. This is the major drawback as an organic producer is not having an easy nitrogen source for application as desired. The plus side of that is synthetic nitrogen sources can cause our calcium to become soluble and leach, delay crop maturation, the highly soluble nitrogen can cause some weed species to flourish, and the nitrogen is available quickly and may not be present as the crop will need it later in the growing season. We must solely rely on manure, compost, legume green manures, and other leguminous crops for nitrogen. Additionally, we must use cover crops, a.k.a. “catch” crops, to hold residual nitrogen that is available between harvested crops to prevent loss of this easily leachable nutrient. We must grow our own N by working our rotation accordingly to fit legumes and cover crops. Nitrogen is an essential nutrient we must grow and manage.
One of the most important things we do as organic growers is to rotate our crops. Crop rotation is an age old method to combat disease and manage nutrients. This also allows a diversity of soil biology to flourish and help the crops. Compared to a monoculture, we break disease cycles and disallow subsequent crops to be plagued by continual disease. When managed correctly we put together the rotation of crops in sequence to maximize benefits. We can put a high nitrogen fixing legume before a high nitrogen demanding crop. We can also coordinate crops with alleopathic effects before crops which are able to tolerate those effects, but benefit from the susceptibility of other weeds. Some crops can loosen the soil and break up hardpan. Some crops provide habitat and encourage beneficial predators. The key to the rotations is to know your crops, their rotational needs and benefits, and how to put it all together. There are multiple reasons to spend time building a crop rotation and the benefits are immense.
Weeds, insects, and disease all have their place and time in growth cycles. It is the grower’s job to manage them. Understand nature’s objective is to hold the soil, kill sick, weak, and diseased plants so only the strong, genetically superior, organisms live on and produce a stronger next generation. Weed’s purpose is to hold the soil in place, fill in bare spots, and maximize production of vegetation allowed by available nutrients. Some weeds also help bring nutrients to the surface to correct a soil imbalance. Weeds are literally nature’s spice of life for the soil. Insects thrive on weak plants. It is there purpose to kill or prevent the reproduction of a weaker plants. We combat them through improving the health of the plant through proper fertilization and crop rotation. General diseases also thrive on weak plants like insects. Through weakened defenses, weak plants succumb to disease and produce inferior quality fruits. Without disease, the same plant would have likely produced an inferior fruit. It is sort of which came first, the chicken or the egg. Healthy nutritious plant, healthy disease free, nutritious fruit. Plants are stationary beings, when given proper nutrition they are allowed to put their full defense mechanisms in place and the defenses orchestrated with symbiotic soil microbes. Whether it is hormone, antibiotic, or other mechanisms, a healthy plant in healthy soils will exert its full efforts to ward off attacks and produce nutritious fruit.
The single most important fact of organic growing is the grower must continually learn. We do not have the toxic rescue chemistries available to conventional growers to combat problem A-Z at the push of the button. We must manage the system, manage our soils, and manage our crops to grow healthy products. We must understand that the soil is a living organism and its biology is critical to the success our crops. We know not all crops will be successful, so we must be willing incorporate those back into our soils. Which is better, a poor crop or adding food for our soil microbial population for the next crop? We also learn more and more about these systems through reading, talking with other growers, and experimenting. Experimenting is the greatest education. Try something you learned, see how it worked, make adaptations as needed, and repeat over and over. Every spring is an experiment to me. The feeling I get at the beginning of a new growing season is pure optimism. Over the winter I read and study new growing systems and management strategies. Armed with this knowledge, I know this year will be better than last. And then through the growing season, I find some things didn't work as expected or Mother Nature threw me a curveball. Oh well, I can't wait til the next spring because I'll have a few more tricks in my bag and I'll do even better." The key point to remember now and always: It starts in the soil; it ends in our health and well-being. Happy organic growing!
Credits
The sustainable farming founders and procurers- Charles Albrecht, Carey Reams, Charles Walters, Gary Zimmer, and many others. Their work transcends through all sustainable and renewable farming systems.