As popular interest in organic gardening continues to grow, the way in which we approach our system of food production is slowly beginning to shift. Industrial farming appears to create an abundance of food, but at what cost? It largely bypasses soil biology, it is puffed up with fertilizers that are artificially high in NPK’s (nitrogen, phosphorous, and potassium) which are derived from petroleum and hence, are unsustainable requiring ever greater input. Even more troubling, excess nitrogen and phosphorous runoff into streams and lakes killing fish and destroying ecosystems in a process known as eutrophication.
Our current agricultural system values quantity over quality, and relies heavily on harmful practices such as:
- Mono-cropping (deprives the system of natural diversity, which is key to ecological resilience against pests and disease)
- Heavy tillage (over-aerates the soil resulting in loss of soil organic matter, damages mycorrhizal fungal networks and disrupts beneficial microbiology)
- Over-fertilization (adds in primary plant nutrients that are missing from depleted soils, but can result in runoff that contributes to eutrophication)
- Pesticide-dependence (destroys insects that attack weakened plants, as well as beneficial insects like bees or lady beetles)
Rather than looking at our gardens and farms as seasonal machines that transform chemical fertilizer into fruits and vegetables, a more ‘organic’ approach encourages us to rebuild and fortify the ecological microcosm of the veggie patch. For the home organic gardener, this means looking at the garden as a long-term soil-building project; a project in working toward sustainability.
Here are some of the basic amendments to get started with:
Compost: Literally foundational to your garden, compost provides some primary and secondary nutrients as organic matter breaks down and carries the beneficial microbes that mediate the whole process. The end product of the breakdown of compost is humus, the most stable fraction of a soil which improves all of its chemical qualities. Every soil bed should be high in composted material.
Cover cropping: The benefits of alternating ‘cash’ crops (anything that ends up on your dinner table) with cover crops are many: Biomass is accumulated and ultimately turned into soil organic matter; otherwise bare ground is prevented from eroding; soil compaction is mitigated reducing the need for tillage; beneficial insects have a home between cash crops; some covers even cooperate with symbiotic partners in a class known as rhizobacteria to fix atmospheric nitrogen into nitrates and nitrites that plants can use! A comprehensive list of benefits and uses literally fills volumes of books written on the subject. Cover crops are often planted in pairs of legumes, which fix nitrogen, and grasses, which creates prodigious biomass through carbon fixation. Check out our selection of cover crops.
Compost tea: One of the best features of compost itself is the array of friendly microorganisms that help plants by breaking down organic matter into constituent nutrients and outcompeting pathogenic bacteria. Compost tea is made by aerating a water solution comprised of a handful of compost (worm castings are best for its rich and wide array of native microbes) with a sugar source in aerated water for 24 hours, resulting in a microbe-enriched tea that you can foliar spray, root drench, or otherwise water into your soil.
Mycorrhizae: Plants benefit from immense underground fungal networks, or mycorrhizae, that facilitate nutrient and water uptake through symbiotic relationships with plant roots. Eastern old growth forests, for example, would struggle to survive in the phosphorous poor soils of the East without the aid of endo- and echo-mycorrhizae. You can inoculate your garden bed with mycorrhizae and encourage these beneficial relationships.
Crushed rock powders: Despite being needed in minute quantities, trace minerals are as essential as the more familiar primary nutrients. By adding azomite, greensand or glacial rock dust into your garden bed, you’re making a full spectrum of minerals available to your plants; in turn, the plants will be more robust and better able to resist pests and pathogens and compete against weeds reducing the need for applications of pesticides and herbicides.
As you begin to transition your garden toward long-term resilience and abundance, it’s often helpful to add fertilizers to compensate for what the soil lacks now but will also slowly release over time. Fertilizers & soil amendments made out of bone, blood, feather, and alfalfa meal, or manures and bird or bat guano, are a good way of adding NPK’s to help boost plant growth and fruit formation this season (relying just on fertilizer season in and season out without measuring current mineral & nutrient levels is where we get into trouble!). Soil tests can help you determine how much amending your soil needs for optimal abundance and long term sustainability. Having your soil tested is free for North Carolina residents and very inexpensive for Virginia residents, through the NCDA (information here) and Virginia Cooperative Extension (information here).
Hopefully some of these strategies, techniques and amendments will help you produce your most verdant and productive garden yet!
By Raty Syka and Andrea Wood