Good soil builds great gardens. Yet few gardeners are blessed with perfect soil. Conventional gardening practices call for the addition of multiple chemical-based fertilizers to enhance the soil, but organic gardeners who eschew such practices need alternatives. The answer lies in replenishing your soil with organic materials to grow healthier, tastier vegetables.
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All gardeners spend a great deal of time and energy on replenishing their soil, but when you switch to organic gardening practices, the care and feeding of your soil is more important than ever.
What Is Soil?
Soil consists of many layers of pulverized rock, decomposing leaves and other organic materials. But surprisingly enough, it also contains air and water. Soil is comprised of 45 percent minerals, 30 percent air, 20 to 30 percent water and 5 percent organic materials.
It’s that last 5 percent that most gardeners concern themselves with when they speak of recharging the soil. Additives including manures, cover crops and compost replenish the nutrients in the soil and improve the soil structure. Like the alchemist’s quest to turn base metals into gold, “brown gold” additives such as compost and well-aged manures transform sticky clay soils one step closer to the much-desired sandy loam.
Start With a Soil Test
Before planting a single vegetable in your garden, test your soil.
Soil tests analyze:
- Soil type (clay, loam, sand, or combinations of these)
- pH (vegetables prefer a soil pH 5.8 to 6.3)
- Macro and micro nutrient levels
Macro nutrients such as nitrogen, phosphorous and potash contribute to healthy leaves, plentiful flowers and healthy roots respectively. Micro nutrients including calcium, iron, copper, magnesium and other minerals enhance plant health. Each plant requires different amounts of nutrients for optimal health and vitality.
Once you have your soil test results, you’ll know what to add to the soil to create the optimal conditions for growing vegetables.
The Care and Feeding of Garden Soil: Organic Amendments
With your soil test results in hand, you’re ready to add amendments to your garden soil to adjust the pH, improve fertility and grow great vegetables.
Compost – By far the best and easiest organic amendment to improve both soil structure and fertility is compost. Composted grass clippings, autumn leaves, vegetables and fruits are safe and easy to add to the soil.
Manure – Aged manures from cows, horses, sheep, rabbits, goats and chickens offer plenty of nitrogen-rich material to the soil. Never add dog, cat or other carnivore feces to your garden. Not only do they attract other carnivores, but they might contain parasites, and who wants to grow a tapeworm?
Agricultural Lime (Ag Lime) – Agricultural lime or pelletized lime adjusts soil pH from the acidic range closer to neutral. It “sweetens” the soil by boosting the pH. When soil is within the proper pH range, it’s easier for plants to absorb and use the nutrients in the soil.
Rock phosphate – Rock phosphate contains pulverized sedimentary rock that offers slow-release phosphorous to plants.
Bone meal and blood meal – Both bone and blood meal are animal by-products from the meat industry, so avoid them if you prefer not to support the killing of animals for food. The byproducts are added to the soil and repel critters such as rabbits, mice and voles while adding macro and micro nutrients back into the soil.
Organic Gardening Practices That Recharge the Soil
As part of your organic gardening practices, it’s helpful to include several gardening practices into your vegetable garden. These practices include:
Crop rotation – Rotating crops with different nutritional needs from year to year helps you avoid soil depletion. Rotate crops by families: plant brassicas one year, legumes in year two, nightshade family vegetables in year three, and so on. If that’s all Greek to you, take a deep breath and check out this free manual — it will help you understand crop rotation and plan it on a small scale in your backyard.
Cover crops – Cover crops harness nature’s own power to replenish the soil. With a cover crop, you sow the seeds of a plant that isn’t intended for consumption on a garden bed, till under the mature plants to nourish the soil, and grow veggies the next year. Cover crops suppress weeds, prevent soil erosion and improve soil health. Typical cover crops include ryegrass, buckwheat, mustard, arugala, white clover and more.
How to Get Your Soil Ready for Spring
Now is a great time to get your soil tested and ready for spring planting. If your garden soil is still hard from the harsh winter, cover the area with a large black tarp pinned down by several stones on each side. In 3 to 7 days the ground should be warm enough to start planting.
There’s an art and a science to soil, but it’s not something you need to understand all at once. Build up your knowledge slowly over time, just as you build up your soil.
Master Gardener Handbook, Virginia Cooperative Extension, 2012
University of Missouri Extension, Soil, Plants and Nutrient Management
Cornell University, College of Agriculture and Life Sciences, Crop Rotation Guide and Cover Crops
University of Florida, Cooperative Extension, Soil Preparation and Lime for Vegetable Gardens
- Off Grid News: 6 Effective Methods to Replenish Nutrients in the Soil