Organic Fertility Principles
Organic fertility feeds soil biology first, which then feeds plants. This indirect approach builds long-term soil health and sustainable productivity rather than providing quick fixes with soluble synthetic fertilizers.
Nitrogen Management
Legume cover crops fix atmospheric nitrogen through symbiotic bacteria. Crimson clover, hairy vetch, and field peas provide 80-150 pounds of nitrogen per acre when terminated at flowering stage.
Compost supplies slow-release nitrogen plus other nutrients. Well-made compost typically contains 1-2% nitrogen, releasing gradually over months as microbes break down organic matter.
Phosphorus and Potassium
Rock phosphate and greensand provide slow-release phosphorus and potassium. These mineral amendments work best with adequate organic matter and active soil biology to solubilize nutrients for plant uptake.
Wood ash supplies potassium and raises pH. Apply conservatively (10-20 pounds per 1000 square feet) as excess ash can imbalance soil pH and nutrients. Best used on acidic soils or potassium-deficient situations.
Micronutrient Management
Kelp meal provides trace minerals including zinc, iron, copper, and manganese. Regular applications support plant health and improve crop quality, especially in sandy soils naturally low in micronutrients.
Compost and diverse organic matter generally supply adequate micronutrients for most crops. Deficiency symptoms indicate need for soil testing and targeted amendments.
Nutrient Budgeting
Track nutrients removed in harvested crops and add equivalent amounts through amendments. Calculate removal rates based on crop yields and nutrient content data. Balance inputs with outputs for sustainable fertility.
Annual soil testing monitors fertility trends. Test every 2-3 years minimum, more frequently when making significant changes to amendment programs. Work with labs familiar with organic fertility management.