Agriculture Reference
In-Depth Information
Using EM
EM is preferably applied in smaller doses, more often. Like compost tea, it could be
daily, weekly, monthly, or seasonally. Application rates are the same for EM and activated
EM, the most common suggested rate for agriculture being 1 to 10 gallons per acre per
year, which is approximately 6 tablespoons to 2 quarts per 1,000 square feet per year,
spread out over as many applications as are feasible.
For some reason, the application rate given for gardens is 1 gallon per 1,000 square feet
per year, which is nearly 44 gallons per acre per year, and the suggestion is generally 1 pint
per application. I've done a lot of research and never figured out why this discrepancy ex-
ists. It may be that it's just more economically feasible to apply it at a higher rate for small
areas, whereas it would get expensive on a big farm. It may be because a garden is con-
sidered a higher-value landscape, or it may be just a marketing thing.
After extensive research into studies that have been done in agriculture, I go for the high
end of the agriculture rate and use 10 gallons per acre per year, which is close to 2 pints per
1,000 square feet per year. More importantly, I generally spread this out into ⅓ cup per
1,000 square feet per month from early spring through late fall. I may not get to the 2 pint
total, but it's more important to me not to use too much EM and to achieve a sufficient dilu-
tion. If you only want to spray three times each year, I still recommend you go for this ⅓
cup per 1,000 square feet rate.
Please keep in mind that more is definitely not always better. Several research trials have
found that 2 teaspoons per 1,000 square feet to be more effective than higher doses. Anoth-
er study found powdery mildew control at 0.4 teaspoon per 1,000 square feet. If too much
EM is applied, studies have found that organic matter may break down too quickly and the
soil may become compacted. For all of these reasons, I believe one pint per 1,000 square
feet is too high for one application in many gardens.
I usually end up diluting it 1:200 with water, or at a bare minimum 1:100, which would
be one to two teaspoons of EM per quart of water. It's technically supposed to be 1:500 or
even 1:1,000, but that's a lot of water and pretty much impossible with a backpack sprayer.
Despite the cold water not being the greatest for the microbes, a hose-end sprayer works
really well for this because you can just set the ratio on the dial and spray.
This ratio also depends on the frequency of application and the area you're trying to cov-
er. For example, daily use through irrigation systems often use very diluted ratios such as
1:10,000. Use on turf and in gardens might be more like 1:100, basically to provide ad-
equate coverage, and then watered in with a sprinkler. Some sources say not to apply it dir-
ectly to flowers or newly seeded areas, as this could potentially ferment the flowers or
seeds. I've rarely found this to be a problem, but it is something to watch out for.
