At Formaggio Kitchen, serious consideration is given to the impact of the land or terroir on each bottle of wine, wheel of cheese and bar of chocolate — for familiarity with soil and its composition yields a deeper understanding of the relationship between the Earth and our food. Many of our biodynamic and natural wine producers emphasize the importance of soil composition as it relates to the health of the vineyard as well as to the expression of the wine. I Clivi winemakers, Ferdinando Zanusso and Mario Zanusso, produce, “as ‘transparent’ a wine as possible, in which soil, climate and tradition may come fully through and be perceived without interferences.”
To understand the complex chemical relationship between the soil and the fruit it bears, it is good to have a grasp of the fundamentals. First, there are four basic components of soil. Water and air are two, each contributing roughly 25% of the final composition. Mineral matter, comprised of stones and gravel from the underlying bedrock, represents another 45%. An important 5% is organic matter — dead plants, dead animals, and the waste of those dead plants and animals.
In order to thrive, most plants prefer a particular soil composition with the correct balance of nutrients and minerals. For example, carrots prefer soil with a high potassium content. Apple orchards thrive in loose, deep soils with a slightly acidic (i.e. low) pH. Factors such as depth, pH, and water availability in the soil will develop the acids and sugars in the fruit, which in turn will influence the final flavor. Those who study terroir in viticulture argue that climate, soil density and water availability will heighten the complexity and influence the taste of the eventual wine.
Soil-focused farming encourages growth and increases productivity in a sustainable manner. And, techniques such as the use of cover crops and crop rotation ease the challenges of farming organically. By definition, cover crops are plants are grown in between harvests to increase fertility, suppress weeds, control pests, lessen erosion and support wildlife diversity. Cover crops may be grown at any time of the year, but are typically started in the fall — about four weeks prior to the killing frost. Also known as “green manure,” traditional cover crops include winter rye, winter wheat, oats, sweet clover and buckwheat. In the spring, the covers are gently tilled, leaving soil that is rich in nutrients and organic matter.
Another soil-focused approach to farming is the use of crop rotation. This can be applied in both large and small scale farming. Crop rotation is a systematic cycle of planting that will fortify the soil, reduce disease, and improve tilth, structure, and water absorption. In a four-year crop rotation, the land is divided into four sections in which crops are organized and planted according to family. For the sake of illustration, imagine a rectangular plot, divided into four quarters. In the upper right-hand quarter, the legumes: peas and beans. Moving clockwise, the roots are next (onions, leeks, carrots), followed by nightshades (tomatoes, peppers, eggplant, potatoes) and finishing with greens (lettuces, celery, broccoli). The following spring, the plants are rotated one quadrant along. Where the legumes once grew are the greens, where the nightshades blossomed, the legumes, and so on.
Finally, one of the most intriguing methods used is intercropping, or companion planting. Companion planting is the practice of growing two distinct crops in close proximity to achieve a symbiotic relationship. It encourages productivity by using the natural chemicals found in plants to add minerals, deter pesticides and fix nitrogen deficiencies in the soil. Edible flowers such as marigolds and borage are harvested and sold as well, benefiting the farmer in ways that cover crops do not. This graphic, courtesy of Nigel Hawtin and New Scientist magazine, brightly portrays the concord between beans and brassicas, marigolds and tomatoes.
So why is this information pertinent to urban inhabitants? Gardening tips aside, encouraging sustainability in urban settings is increasingly necessary. By purchasing intelligently farmed fruits and vegetables, the consumer is supporting a sustainable agricultural system – for carefully nurturing crops in their preferred habitat eliminates the need for pesticides, genetic manipulation and intensive watering. To understand these techniques and why they benefit the land and the environment aids in making informed decisions at local grocery stores and farmers markets, hopefully bridging the gap between farmer and consumer and leading to a fuller appreciation of organic agriculture.
If you are a Massachusetts-based gardener and are interested in having your soil tested, the Soil and Plant Tissue Testing Laboratory at the University of Massachusetts at Amherst will analyze your soil for you for a small fee. If you are growing food for consumption, it is particularly important for checking lead levels but you receive a host of other information with your analysis, including fertilizer recommendations.
Emily Shannon is a cooking enthusiast and works in the produce department and as a cheesemonger at Formaggio Kitchen Cambridge.