Healthy soil for a healthy garden, healthier world

The soil around Sacramento is pretty soggy today, a normal situation for December. We gardeners know not to walk on or dig in soggy soil, which can harm its important structure by destroying microbial relationships and pressing out the air. When it dries, clay soil without air basically is a brick – bad for the gardener, the plants and the soil’s health.

Tuesday, Dec. 5, marked World Soil Day, established to recognize and celebrate the amazing world under our feet. The theme for this year's observance, selected by the United Nations, was “Soil and water, a source of life.” 

We can’t underestimate the importance of soil health. Parts of the world have soil that’s been so overworked, eroded or contaminated by heavy metals that it can’t support life, and that’s a tragedy.

So it’s appropriate to appreciate our soil every day. Here are ways to boost and maintain healthy soil at the garden and neighborhood level:

– Minimum tillage. That noisy rototiller is totally unnecessary to planting and harvesting healthy crops. Keep the hand tilling or “double digging” to a minimum, too. 

– Crop rotation. Be aware of the plant families, and avoid planting members of the same family in the same spot year after year. Tomatoes, for example, should not be followed by peppers or eggplant, all members of the Solanaceae family. Try garlic (Amaryllidaceae) or spinach (Amaranthaceae) instead.

– Addition of organic matter. Compost, worm castings, aged animal manure, leaves and kelp meal are all appropriate soil amendments. And you don’t even have to dig them in: Spread them across the top of the soil and let the rain (like now!) or irrigation do the work to enhance the soil below it.

– Planting of cover crops. This isn’t called “green manure” for nothing. A cover crop – vetch, clover, bell beans or winter rye, for a few examples – planted now will grow over winter. It then can be cut down in February, raked into the soil and be broken down in time for planting summer vegetables.

Healthy soil also can enhance water infiltration and storage, did you know? The practices mentioned here contribute to carbon sequestration, too. So when we keep the soil healthy, we help the fight against water pollution and climate change. Our world's health starts with what’s underfoot.