“So,” Bob, Jr. says, “now that we know the quality of produce we need, we then devise our growing methodology to achieve that. Everything – and I do mean everything – is predicated on the health of the soil. So, we need to make decisions about how to manage our soil in three different ways: physically, biologically and chemically. And, although overall soil health is crucial for quality crops, it’s the top two inches of soil that’s of most importance, since that’s where the vegetable roots themselves will grow.”
Physical structure of the soil: are the soils compacted, what is the physical make-up of the soil composition; clay, sand, silt and loam, are the four types of every soil. What makes proportion of each material determines how soils hold water and nutrients and how the soil particles bind to one another.
Biological: how much and what types of biological activity is occurring in the soils. The numerical counts as well as the diversity of species is critically important to good soil health.
Chemical: How much mineral and in what relationship to each other is also a huge factor in not only soil health but a precursor to good plant health. We utilize a concept called soil balancing which in essence is balancing the mineral content of the soils to maximize the availability to the plants in the appropriate amounts.
All three of these soil health factors are important alone, however an exponential improvement happens when all three are in balance with each other. The most interesting phenomenon that we have discovered here on the farm over the years is how much a good cover crop regime can positively affect all three legs of that stool. The benefit of healthy roots growing in the soil has positive attributes to the physical, biological and chemical aspects of the soil.
Specifically relating to cover cropping, what the farm does to prepare for summer crops is similar to what’s done other times of the year – but in more depth, with extra steps taken. Here are more specifics.
“First,” Bob, Jr. says, “land shouldn’t be barren. So, after last year’s crops are harvested, we plant a cover crop on the land.”
Steve Giles from The Chef’s Garden expands upon the science behind cover crops. “The ground,” he explains, “is not dead. In fact, soil is its own ecosystem, and the more you can do to keep it vibrant and alive, the healthier the crops will be.”
Cover crops can include oats, rye, buckwheat and sorghum as four examples. The cover crop of choice is then planted in a field and grown for a relatively short period of time, with the oats, for example, growing about six to eight inches tall. Then the cover crop is harvested and worked into the soil itself. The dual purpose of this process is to control weed growth and to feed the soil. This process is repeated, as needed, before stale seed beds are prepared.
“This is the stage where we lay out the beds for our vegetable crops and let weeds germinate but not emerge,” Bob, Jr. explains. “Then we shallowly till the ground, disturbing the weed hairs. If we dig too deeply, we’d be bringing up a new round of weed seeds. If we’d wait until the weed actually emerges, then it’s much more difficult to kill them. Because we kill them early on, these weeds are simply white root hairs that quickly desiccate in the wind. After we repeat this process two more times, then we’re ready to plant the summer crops.”
If it sounds like there is a lot of physical work involved in this process, you’re right – and so it’s only natural to wonder why all these extra steps are being taken. Bob, Jr. shares two key reasons. “First,” he says, “this process allows us to have far less competition from weeds. And, even more important for chefs, this is what allows us to eliminate the need for chemicals. Sure, we could do one quick till and then pour chemicals onto the land, but we’re never about minimum standards. We want to produce healthy, nutrient-dense products for chefs without harming the land for future use.”