If asked to define organic farming, people’s responses would probably include the prohibition of synthetic pesticides and fertilizers, but could also touch on native pollinators, micronutrients, organic matter, examples of resource-conserving techniques, or any of a number of other elements. What do these things mean? Why are pollinators important? Why is water conservation important? What is a good soil organic matter definition? What is carbon sequestration? Here are some organic practices and objectives.
Produce Healthy Plants
Providing better nutrition to the consumer is a frequent production goal and is commonly identified in terms of Brix levels. Brix is a term referring to the degree to which light is bent when passed through a fluid. If the fluid is derived from a plant, the reading will indicate the amount of sucrose, fructose, vitamins, minerals, amino acids, proteins, hormones, and other solids it contains. These components translate into nutrition and flavor.
High Brix readings are beneficial beyond contributing to human health. They indicate a proactive insect pest and pathogen defense for the plants. As insects have no pancreas, they cannot consume plants high in sugars–so they don’t. Likewise, pathogens have difficulties colonizing very healthy plant tissues. This all spells pest resistance. Additionally, high-Brix plants form mutually beneficial relationships with soil microbes through which they exchange a portion of their sugars for the trace elements and other nutrients that the microbes can more readily source from the soil. Healthy plants are encouraged by many of the practices below.
Increase Mineral Availability
Though the organic component of soil is quite important (of course), plants also need certain minerals to perform their functions and achieve optimum growth (and to provide these minerals to those who eat them). They are referred to as macronutrients or trace elements, depending on the quantity of each required. As indicated, soil microbes help to gather such minerals for plants. However, they must be present in the soil first. The addition of mineral-rich soil amendments including greensand, limestone, gypsum, epsom salts, cobalt sulfate, and granitic and basaltic rock minerals (to name a few) can be used to correct specific shortages.
Encourage Beneficial Garden Insects
For farming systems that strive to work with or mimic nature, insects are important players. From pollination to insect pest predation, there are many niches to fill.
Why are pollinators important? More than simply increasing crop yields, around 90% of the world’s leading food crops rely on their pollination. Honey and native bees are not the only insects to perform pollination. Some wasps do, flies pollinate (especially the hoverflies and blowflies), and there are also butterflies, moths, and even leaf beetles contributing their time.
And beyond pollination? Depending on what they are, beneficial garden insects can act as insect pest predators, break down organic matter (classic organic matter examples being dung and crop residues), condition the soil, and scientists have even demonstrated that plants exposed to the sound of bee buzzing will automatically increase their sugar concentrations.
Encourage Soil Microbes
As indicated, soil microbes play a critical role for plants in gathering soil minerals. Additionally, the ability of plants to mine moisture from the soil as well as the formation of soil humus (an organic component of soil) are both greatly enhanced by microbes. But how do you nurture them? Maintaining adequate soil moisture levels is key, as microbes need moisture to carry out activities. Quite importantly, soil structure/aggregation should be improved/preserved to offer them the best growth conditions. Overtillage is detrimental to soil microorganisms. It is especially destructive to those with a spreading structure like mycorrhiza that requires rebuilding with every soil-disturbing event, and to nitrogen fixing bacteria which are especially dependent on aggregates/good soil structure for their existence.
Another activity damaging to soil microbes is leaving soil bare for 6 months or more. Therefore, covering the soil surface year-round is a common practice and important for various reasons. It provides a physical barrier which protects against the forces of weathering (destructive to soil structure) and evaporation. This can be achieved with mulch or, to offer a food source to soil microbes, the constant presence of sugar-delivering plant roots is required. Green manure, cover crops, and living mulches are invaluable here (particularly the winter-friendly cover crops).
Improve Soil Moisture Capacity
Moisture is, of course, incredibly important to plants, and the ability of soil to hold onto it is equally important. Soil with good aggregation and organic matter content holds water in place more readily. Good soil moisture capacities ties in nicely with water conservation, or the timely and appropriate use of water with minimized waste. Holding moisture in the soil longer increases the likelihood that plants can access it, so less water can be used. Reducing potential losses through evaporation (by mulching), and watering deeply and less frequently to encourage more extensive root development for better extraction also reduce the need to overuse this precious resource.
Be Carbon Positive
This can be achieved by reducing carbon release and by increasing sequestration. What is carbon sequestration? Definitions state it is carbon capture, the long-term storage of carbon forms in the soil, as with the production of organic matter. Examples of other carbon positive practices include the extensive use of carbon-rich compost by those who use raised beds. For a different style of raised bed, practitioners of mound gardening or Hügelkultur use tree logs as well as hedge clippings and brushwood to create a kind of composting-in-place bed, so to speak. Note that these gardening styles have differences beyond how they keep carbon in the soil. To compare the raised bed vs in-ground production, raised bed vegetable gardening often offers better drainage, superior soil structure, more efficient use of space, and a shorter distance to bend for the gardener! However, in-ground production doesn’t necessitate the level of irrigation required for beds and is an easier system to introduce green manures/cover crops into.
To reduce carbon release, what isn’t helpful and what is? Tillage is not, as it releases carbon into the air. Therefore, a popular tactic to prevent carbon release is conservation tillage. Definitions of conservation tillage stress both the retention of crop residues on the soil and the minimization of tillage operations themselves. Also called reduced or low-intensity tillage, specific methods include no-till (no tillage with full crop residue soil coverage), ridge till (reduced tillage/vehicle traffic), strip till (reducing tillage to strips with some crop residue soil coverage), and mulch till (tillage with mulched soil coverage). And of course, raised bed vegetable gardening often requires little or no tillage. Additionally, intentional animal grazing that maintains plant health and growth (and therefore maintains sequestering), a focus on perennials, and avoiding the excessive application of nitrogen-rich fertilizers also reduce carbon release.
Though it is important to answer the question “what is” carbon sequestration “why” is an equally significant question. Whether working with garden rows or mounds, bear in mind that sequestering carbon isn’t just a positive for the environment, it is a resource for soil improvement and plant growth. To raise carbon-based organisms, you must have present carbon–organic matter! Examples follow next.
Increase Soil Organic Matter (SOM)
What is organic matter? In soil, it is important. It performs many functions, from helping retain moisture and nutrients to improving (and maintaining when good) the physical condition of the soil. Soil organic matter is, quite generally, carbon-based (i.e., organic) materials at various stages of decomposition. Good organic matter examples for addition to the soil include past crop residues, decomposable mulches, yard waste, compost, and dung. Another favorite method for the increasing of SOM is the use of green manure, cover crops, and living mulches. These practices all involve the growing of a plant which will not be harvested but rather is returned to and used to condition the soil. They differ in their timing. A cover crop is grown in between cash crops–in other words, during winter for Zones 3 to 7. When a crop is grown during the main growing season it is called a living mulch (when it is interplanted with cash crop rows) or, when the only crop present, a green manure. Definitions show that these differ in their timing and handling, though they are not always different plants. Crimson clover and hairy vetch are two examples of such multiple-use crops.
Include Plant Diversity
The benefits gained from plant diversity are manyfold. When striving to support a diversity of beneficial garden insects and soil microbes, using a diversity of plants is a natural, offering different habitats and food sources, and root exudates. Additionally, different plants perform different functions in terms of contributing to soil improvement. Legumes fix (pull) nitrogen from the air. Grasses hold nitrogen in the soil. There are many crops of each which produce large quantities of biomass both above and below ground level, thus contributing organic matter when terminated. Examples of biomass-rich plants include the legumes mammoth red clover, white Dutch clover, and yellow sweet clover, and the grasses oat and rye. Of course, the practice of plant diversity can apply to both soil-improving and cash crops.
Integrate Animals
The mimicking of a natural system will include animals. This may mean creating areas attractive to desirable wild animals that pollinate plants and/or provide some insect pest control (various birds, bats, etc.). Or it may mean domestic animals. Whether used to actively engage in work on the farm (such as chickens turning compost piles, cattle moving through fields and clearing crop residue, etc.) or merely as a producer/processor of carbon (animal manure being one of the most wonderful organic matter examples there is), the farm system becomes more closed and complete when animals are included.
Though they share common goals, many people do organics a little differently from one another. How will you do organic?
About the Author: Leah Smith is a freelance writer and home and market gardener. She works on her family’s farm in mid-Michigan called Nodding Thistle (certified organic 1984-2009, principally by Organic Growers of Michigan). A graduate of Michigan State University, she can be reached at noddingthistle@gmail.com.
