When people define organic farming, it should include, "grown without the use of synthetic chemical fertilizers and pesticides." What this usually evokes is a field of sunshine happy vegetables that never receive anything but water and compost. Within organic, no synthetic chemicals are used but there is a broad spectrum of accepted amendment practices. On the left, you have those who believe that the natural interactions between living and non-living organisms in a biodiverse ecosystem will keep the peace. On the right, you have growers who take an Integrated Pest Management (IPM) approach monitoring the different life cycles in the growing environment and use "organic approved" remedies to keep the weed and pest population in check. In the middle, are those who lean to the left but are pulled to the right on occasion.
My philosophy is...farm management style will determine where on the spectrum a grower falls. I've identified three key areas of farm management...biodiversity, soil health and organization. Yes, organization! In my opinion, to be a successful farmer, you must run a tight ship with a planting schedule, record keeping, discipline and protocols. Being organized builds resiliency in a farming practice because it helps a farmer take a whole systems approach to managing their farm, systems that are less reactionary to economic and climate fluctuations, i.e. one crops fails but the farmer has back-up crops, anticipating a wet spring can help a farmer adjust their planting schedule. But most importantly, an organized farmer will "know" their farm keeping a watchful eye for intruders and outbreaks. Observation can be the best line of defense.
Biodiversity measures the variety of different life forms around the farm from bugs and bees to livestock and wildlife as well as woodlands. Imagine an ecosystem. A farm should mimic those principles. Biodiversity, however, can also include crop diversity. Monocultures (growing one crop in a field) are risky because the crop is more vulnerable to attack. One pest and the whole crop goes down. And monocultures give and take the same nutrients from the soil year after year creating an imbalance and depleting soil of essential minerals. With polycultures, you grow a variety of different fruits and vegetables...a few rows of this, a few rows of that, etc. From year to year, different plants enrich the soil with nutrients that will benefit next year's crops. But even within the same year, crop's inter-planted together (intercropping), or in immediate succession, can have a positive exchange. Above ground, hedgerows or "trap crops" can attract pests away from market crops. It can sound a little like whose on second but here's an example..on the edge of a squash crop, sunflowers are planted to attract insects. The secondary benefit is birds will then eat the insects off the sunflower. Below ground, the chemical make-up of one crop can help mitigate soil-born disease for another crop or reduce the proliferation of certain weeds.
Plants aren't totally helpless though. They have natural defenses to ward off pest and disease. But these natural defenses are only as strong as the soil. The soil is like a plant's immune system. Just like humans, when our immune system is low, we get sick. As a rule, soil that is properly amended with compost, receives a cover crop in the winter and different crops each growing season will produce healthy plants.
When we look at the different applications, many sound pretty safe. Take Surround for instance. it is made from a type of clay, kaolin. When sprayed on a plant it leaves a non-toxic, milky barrier that bugs don't like or have a hard time eating through. It's approved but should it be applied as a prophylactic or only when necessary? It's easy to give these "organic approved" substances too many liberties. Just because a product is deemed "safe" doesn't mean it can't have adverse effects. Routine and in discriminate applications can enable bugs to develop resistance. Insecticidal soaps seem pretty benign. They can be used to to kill bugs when hand-picking or spraying water doesn't work. It can be bought or made at home with a simple recipe. It's safe for the garden and isn't harmful to most beneficial insects but does that give it free reign. Sean Swezey, a professor at UC Santa Cruz, said it best, "Don't think conventionally when problem solving in organic farming."
Another product is corn gluten, which stops the germination of weed seeds. All reports look good and it is ecologically safe but is the corn GMO? And can the additional nitrogen in the corn gluten overload the soil (doing an annual soil test is important before using additives)? One product I've been researching is Sluggo Plus. The active ingredient is Iron Phosphate which is naturally occurring in soil so when dissolved, it acts as a nice soil amendment. But it also includes spinosad which attacks an insects nervous system forcing them to stop feeding and die. While non-toxic to most beneficial insects, except honeybees, who are we to say what is beneficial or not. We humans know a lot about insects, organism and bacteria but we don't know everything.
Even if "organically approved," insecticides can be broad-spectrum killing non-target bugs which disrupts the garden's biodiversity and its ability to self-regulate naturally. Kill one bug and next there is an explosion of another pest which use to get eaten by the bug that was just killed. It begins a vicious cycle of pest control measures. Other alternatives include introducing parasites to attack the target pest. While natural, mishandling of his method can backfire. But studies show that when done correctly the ecosystem is more likely to self-regulate the populations than with an insecticide.
I don't claim to be an authority. Just a regular Josephine trying to make sense of it all. But I do believe...a rigorous and thoughtful schedule of cover crops, crop rotation, intercropping and compost will enable a farm of, any size, to take care of itself with minimal to no foreign inputs. Run an organized, biodiverse farm and the soil will deliver.