The Seven Tenets #3: Strike a Balance
Natural systems are all about balance. When equilibrium is lost, the whole system can begin to collapse, such as when we clear-cut trees from the side of a mountain or remove large predators from the food chain. In the garden, balance comes in the form of many little parts that make up the whole. Good examples are rain runoff to rain harvesting, good bugs eating bad bugs, ground cover and mulch stopping erosion, and the Carbon-Nitrogen cycle.
The Carbon-Nitrogen cycle provides a great lesson in balance. These two elements need to be in balance for the soil’s biology activity to flourish and provide nutrients for your plants. The ideal ratio is 20-25 parts Carbon to one-part Nitrogen. If this ratio is out of balance, the soil activity starts to die. For example, when we add a high NPK (Nitrogen, Phosphorous, Potassium) fertilizer to the garden, soil organisms respond by aggressively consuming the nutrients and multiplying rapidly. They consume available carbon in the process. If there is not enough Carbon (i.e., organic matter) available, the microbial activity dies out over time, leaving the soil inert and lifeless. Toby Hemenway, in his permaculture book, Gaia’s Garden, describes this process as being “analogous to a whopping metabolic rush that a big dose of sugar can give you: a great short-term blast, but one that depletes other nutrients and leaves you drained.” To make matters worse, many pest organisms have adapted to survive in these depleted conditions and seek out your plants as the sole source of carbon.
You can strike a balance in the garden or on the farm with the following tactics:
Add organic matter: Add plenty of organic matter to your soil to aid in the carbon/nitrogen balance. Compost is the single best source of organic matter. Manures are fine, too, but they are best if composted or allowed to “mellow” for a few months before adding. Covering the soil with organic-based mulches is another way to foster biological activity at the soil surface and build up the percentage of organic matter.
Don’t rely on high number fertilizers: I use higher number fertilizers sparingly as a soil building ingredient. For example, a high nitrogen fertilizer is useful to help kick-start the decomposition of organic matter that has been added to my soil, such as a winter killed cover crop. It is also important to choose fertilizers that contain trace minerals and humic substances such as humic acid, which are critical to carbon cycling and plant nutrition.
Minimize soil disruption. Limit tilling to facilitate planting, and bed formation, but keep as much of the root zone intact as possible to allow the soil ecosystem to develop. Deep and frequent tilling disrupts the biological cycles that help convert organic matter to plant food. I use a broad fork, which is an indispensable garden tool to help you lift and aerate the soil without disrupting the distinct layers. A good quality broad fork isn’t cheap, but it is a very good investment.
Interplant with flowering species. Any farm or garden landscape should include flowering plants, including herbs, flowers, shrubs and trees. The umbelliferous flowers are a great option to attract beneficial insects – not just bees and other pollinators, but also predatory insects that can keep pests in check. These plants are from the Apiaceae family (commonly known as the carrot, dill or parsley family) and have umbels, or clusters of tiny flowers small enough for predatory insects such as parasitic wasps to insert their mouth parts to gather nectar. Other flowers in this family include cilantro, baby’s breath, caraway, fennel and celery.
Create habitat for vertebrate predators: Attract snakes, toads and other garden predators to your plot. You can accomplish this with a water source, shelter such as a wood pile or other cover and a little patience.
