Another light frost, hail and rain visited Full Belly Farm last week, even though it’s late May. There’s no plant that we can think of that appreciates hail on its tender leaves. The summer corn, tomatoes and melons are socked in out in the field, waiting for their roots to warm up so that they can get moving with the business of growing, something that all our summer crops will do only when the sun finally comes to stay for awhile. Maybe we’ll stand on the sidelines watching it happen when the time comes—counting the inches of corn stalk grown by each plant every day!

We’ve hosted several visiting groups this week: staff from state agencies developing new water quality regulations for agriculture, and undergraduate students from U.C. Davis studying different farming models. The students arrived with the hail and rain and moved as a pack down the farm lanes, trying to find warmth in each others bodies. By the time they left I think they were all dreaming of warm showers and hot tea. I’m quite sure that the heaters in each of the white University vans were all blasting on high for the entire trip back to Davis.

We’ve been getting lots of interesting questions from visitors and CSA members about our soil and how we keep it fertile. Where does the soil get the capacity to produce, year after year, sometimes as many as three crops in one year coming from one field? All good farmers add back into their soil to replenish if after the tons of harvest that are removed each year, and on our farm, we believe that the soil is more than a medium for growth and is a cornerstone of the sustainability and resilience of the farm.

Plant nutrients can be provided to plant roots in ready-to-absorb, water soluble forms or in more complex organic forms that require the services of microbes before being available to plants. When we spread compost on a field (as we do prior to planting any crop) or turn under a clover cover crop, we’re providing food for billions of microbes in the soil! This may seem a bit circuitous as a way to provide nutrients to our crops, but good compost is a well balanced diet. Once the microbes get to work, all the trace nutrients as well as the major nutritional building blocks for plant growth are released slowly over the life cycle of the crop.

So our answer to the fertility question starts with the fact that Full Belly uses compost and cover crops to build up the organic matter in our soils and provide sustained fertility. Add water and oxygen and you’re on a path to healthy crops! High organic matter in the soil is also important as a way to improve water retention—this can be especially critical when water is in short supply and is one of the reasons that organic techniques make sense in countries where irrigation and bagged fertilizers are not available to most farmers.

We also believe that when we encourage the microbial life in our soil, we achieve some protection from soil-borne diseases. That isn’t always true, but certainly when soil is fumigated—ostensibly to protect plants from soil diseases—the benefits are short lived. All too soon the microbes return, and the ones that get there first and find the wide open spaces of a fumigated soil, may not be the beneficial ones! Just as we think of some insects, like the lady bug, as “beneficial” because they consume pests, the microbial world is full of complex interactions between various different microbial populations. Wipe one type of microorganism out and other populations will shift, or something else will take its place.

One type of fungus in the soil that is often not thought a lot about in agriculture are the mycorrhizae. These fungi associate with the roots of most plants, including crops, and in an organic system are very important in the uptake of phosphorus and other mineral nutrients. Plants with healthy mycorrhizae on their roots are also more resistant to soil-borne diseases and to the effects of drought. This was all explained to us over lunch by one a visiting student who is studying mycorrhiza on tomatoes. The tendency in some types of agriculture to mistreat soils in various ways that harm their microorganisms becomes less and less defensible, the more one learns.

One of the things that I like to do with the visitors that come to learn about our farm, is bring them to our compost pile. We buy it from a nearby firm that specializes in producing compost. It has been watered, turned and aged just the right amount. Its temperature was taken and carefully recorded several times while it was maturing. Tests have been run on it and finally it has been certified ready to be used on an organic farm. Perhaps some of the guests think that the compost will smell of decay or manure, or be messy. But the pile is dark brown, the compost is fluffy and clearly very well broken down, and the smell is wonderful—a mysterious smell that reminds one of healthy soil on a warm day.

By Judith Redmond, Full Belly Farm

No related posts.