Organic matter comes from multiple sources—old leaves, decomposed plant material, manure, feathers and even decaying animals. Compost converts large chunks of debris into smaller forms that plants and soil microbes can absorb. Another vital source of organic matter is the living biota in soil—roots and microorganisms that release nutrients into the soil but also break down into organic matter when they die.

As gardening season begins, now is the time to build organic matter in your soil. Here’s how:

PLANT COVER CROPS

Cover cropping with grasses and legumes dominate weeds, shade the soil for better moisture retention and reduce compaction by sending roots deep into the subsoil where the next crops’ roots will be.

Cool-season annuals planted in the next few weeks will grow through April. By May 1, cut them down with a weed whacker or apply pure vinegar (30% acetic acid) and allow the debris to decompose for two to three weeks. By the end of May, the soil will be ready for new seeds and transplants.

MIX ANNUALS WITH GRASS & CLOVER

Mixing annuals like mustard, kale, radishes and turnips with grasses and clovers is another way to boost organic matter.

 Mixing annuals like mustard, kale, radishes and turnips with grasses and clovers is another way to boost organic matter. These plants die at the end of their season, leaving roots and debris that decompose quickly. Farmers often plant oats alongside new alfalfa. The oats provide shade and nutrients for the alfalfa, and when they die, they form a natural mulch while enriching the soil with decaying roots.

INCREASE MOISTURE RETENTION WITH ORGANIC MATTER

Think of organic matter as tiny sponges in your soil. One hundred pounds of compost can hold up to 185 pounds of water. Each 1% increase in organic matter expands a soil’s water-holding capacity by 20,000 gallons per acre. This not only helps after rainfall or irrigation but also reduces how often you need to water.

Organic matter also supports fungal networks that transport water molecules from areas of high concentration to plants that need it—even those on the other side of the yard!

BOOST SOIL HEALTH WITH HUMUS

As organic matter breaks down, it transforms into humus, turning soil from brown to rich black. Humus gives compost its earthy smell and aids in soil fertility, structure and moisture retention. It holds four to five times more water than clay and provides a 3D structure ideal for storing water, giving a home to soil microbes, supporting soil porosity and absorbing nutrients that are released as plants grow.

As humus further decomposes, it produces humic acid, which also increases the water-holding capacity of soil, boosts seed germination and increases the permeability of the plant root cell walls. It also creates fulvic acid, a fast-acting compound that improves mineral uptake and helps plants withstand heat and drought.

USE NATURAL FERTILIZERS

Long ago, roaming mammals enriched the soil with manure, fur and feathers. Today, we must supplement with bloodmeal, bonemeal, feathermeal and similar products to mimic the nutrients nature once delivered naturally. These fertilizers contain essential minerals, amino acids and microbes that improve soil health.

You can also boost organic matter with leaves and aged manure. High-quality compost and natural fertilizers are the best option for avoiding weed seeds and providing nutrients to the soil. Even lawns and landscaped areas benefit from an extra dose of organic matter.

MARCH PLANTING DATES:

The ideal planting dates on the biodynamic calendar are March 6-19. Peppers and onions like to be seeded this month, along with all the cool season crops.