Organic soil health is generally seen as the foundation of successful organic vegetable production. Assessing soil health has been likened to a routine medical examination for a person, when a doctor measures a number of key parameters as basic indicators of overall system functions.
Before starting our organic crops, we needed to understand the status of the soil’s health.
Is it healthy? If not, what do we need to feed it so it can feed the plants? We sent a soil sample off to a lab for a diagnosis. The ultimate goal for soil is to be healthy, fertile, and biologically active soil with improved structure and enhanced nutrient availability.
Using organic methods of soil management should provide plants with a good balanced diet. Basically, there are four categories of organic amendments: manures, meals, minerals and compost. Amendments serve as fertilizers, but many also have beneficial effects of the soil. The difference between an amendment and a fertilizer is determined by its effect on plant growth. Fertilizers affect plant growth directly by improving the supply of available nutrients in the soil. On the other hand, amendments influence plant growth indirectly via improvements in the soil’s physical condition (e.g., soil tilth, water infiltration). In short, as the Placer County Farm Advisor puts it, “Fertilizer is like a vitamin pill, amendments are like eating vegetables”.
Our soil sample revealed low levels of organic matter and nitrogen. We began feeding our soil a combination of three organic amendments: horse manure, blood meal and compost. Last fall, we planted a cover crop, also called green manure. Green manures are crops that are incorporated into the soil while they are still green and succulent. Decaying cover crops provide nitrogen (mostly legumes), which improves organic matter and soil structure, and reduces soil erosion-just what the soil doctor ordered!
Healthy soil produces healthy plants which promote healthy bodies; good food medicine!
Using Organic Amendments, Cindy Fake, Placer County UCCE Farm Advisor
Organic Soil Amendments and Fertilizers, UC, Davis
Soil Fertility Management for Organic Crops, ANR
Placer County Real Food Cookbook, Joanne Neft with Laura Kenny