EDUCATION · TERRAFERM
How Effective Microorganisms Are Used in Agriculture
Where EM fits in soil, compost, and plant care — and how the same science carries over to animal agriculture.
Core Use Cases
Effective Microorganisms (EM) shows up across several areas of plant and soil care, each with a slightly different goal:
- Composting and bokashi — speeds breakdown of organic material and helps control odor during the process, often used to inoculate a new pile or bokashi bucket.
- Soil drenches — applied directly to soil around plant roots to support microbial activity and organic matter breakdown over a growing season.
- Foliar sprays — applied to plant leaves at a more dilute ratio than a soil drench, typically as a lighter, more frequent supplement.
- Pond and water management — used to support cleaner water and reduce organic buildup on pond surfaces and edges.
In livestock and poultry operations, the same family of microbes is applied through water lines and litter treatments rather than directly to soil. TerraFerm’s poultry program is one example of that use case in the field.
How Application Works
Application is straightforward in principle: EM is diluted with water — ratios vary by product and use case, from very dilute foliar sprays to stronger soil drenches — and applied directly to the target area: soil, compost pile, plant foliage, or a poultry house’s water line.
Frequency depends on the goal. A one-time compost inoculation looks different from an ongoing soil-health program applied on a recurring schedule through a growing season. Weather, soil type, and what you’re trying to accomplish all factor into timing — there’s no single universal schedule that fits every operation.
Always follow the specific ratio and timing from the product you’re using rather than a one-size-fits-all rule. For how to make activated EM, see TerraFerm’s Activation Guide page.
What to Expect
EM works gradually, through biological activity, not on contact. In compost, that usually means faster breakdown and less odor within the first cycle. In soil, changes build over a season or more as microbial populations and organic matter accumulate — it’s not a substitute for good agronomic practice, just a supporting input. In animal housing, the comparable timeline is measured in days to weeks of consistent application, not a single treatment.
Where This Fits in TerraFerm’s Mission
TerraFerm’s education and consulting work centers on this same application logic, adapted to the operation. The poultry program is a clear example — water-line and litter application aimed at cleaner litter, lower ammonia pressure, and more stable house conditions.
The same underlying principles — dilute, apply, observe, adjust — carry over to soil and plant use cases outside animal ag. For the broader science behind all of this, see What Are Effective Microorganisms.
COMMON QUESTIONS
Effective Microorganisms in Agriculture FAQ
How often should EM be applied to soil or plants?
It depends on the goal. A single application to jump-start a new compost pile is different from an ongoing soil-health program, which is typically applied on a recurring schedule through a growing season. Follow the specific product’s recommended frequency. See TerraFerm’s ASAM Usage Guide for ASAM usage and dilutions.
Is EM safe for edible plants?
EM is widely used in food-crop settings as a soil and foliar input, but always check the specific product’s labeling and any relevant food-safety guidance for your operation before applying near edible crops.
Can EM be used in both soil and animal agriculture?
Yes — it’s the same underlying microbial science, applied differently depending on context: soil drenches and foliar sprays for plants, water-line and litter application for poultry and livestock.
Does EM replace fertilizer?
No. EM supports microbial activity and organic matter breakdown; it isn’t a substitute for a nutrient program. Most growers use it alongside their existing fertility plan, not instead of it.
How long before I see results?
It varies by use case. Compost benefits (faster breakdown, less odor) are often visible within the first cycle. Soil and plant benefits build more gradually, typically over a season or more of consistent application.