Hi, I am looking to apply compost tea to our field crops (50 acres). Has anyone worked with brewing and spraying larger areas? I am wondering about testing to know the amount of bacteria and fungi present etc.
I have done this on small gardens and a portion of an apple orchard at other locations where I mixed worm castings with water, aerated and sprayed over the areas with a pump.
I don’t have any personal experience brewing and applying compost tea, but I just happened to watch an episode of SRC’s (French CBC) “La Semaine Verte” that had a 10-minute segment on compost tea being brewed and used on a pretty large scale. You can probably use Youtube’s built-in caption tool to translate if your French is a little rusty:
Hello, We used compost tea almost exclusively for fertility on the fields. 1,000L tanks in our barn with aerators. The end product should have live culture, hence the aeration. We suspended our own finished compost in filter bags (we used maple syrup filter bags), inside mesh onion bags (free!). A small, multi-gang aerator pump worked well. We also put a timer on it so it wasn’t running 24 hours/day, but it does need to run most of the time. Upon advice from soil experts, we also suspended alfalfa pellets and calcium in the tank. I wish we had done this 15 years ago. We used backpack sprayers for a while, then I built a 200 gallon tractor mounter, pto sprayer. It was fantastic.
Wow! That sounds like my dream come true. Would you mind if I gave you a call sometime to pick your brain a little? I know it’s a busy time of year.
Awesome! Thank you, I will definitely have to translate, my french is extremely rusty. 
613.464.9618. Text first. Gerry
What crops are you using this on @Tullyswayfarm ? If you have a minute I would love to see photos of your setup!
I have retired now. Will see if I have old pictures. 1,000L tank, with aerator, raised up on pallets for access. Suspended filter-bags of our own finished compost, calcium and alfalfa pellets. (nutrition, calcium availability and nitrogen). Live pieces of tree bark each week. (live positive pathogens). Indoors. Approximately 6 weeks, to finished tea. I use a 200 gal sprayer that I made, with collapsible 12’ boom, and pto roller pump. I wish I had done this 20 years ago. I either filled at 50% tea/50% water and used immediately, or stored, short-term in 25 L Tanks. Aeration is key, so don’t store for more than a day. If you need more due to operation size, add another 1000 tank.
I’m curious how long the tea can be in the aeration tank before you would have to clear it out? Or in other words, how long is the tea good for in the aeration tank? Or does it hold indefinitely if you give it adequate oxygen and nutrients?
Also, how does one know that the tea is alive and\or “good”?
I aerate til use. Aeration keeps it 'alive. I do store not aerated in the winter for some light nutrients in spring seeding trays. I have never tested to see how alive the aerated tea is, but I have good resource people to rely on for scientific opinion.
Gerry
@Tullyswayfarm : That’s really cool. How often do you apply the compost tea and for how long? I’m curious if you have any anecdotal experiences of what the optimal regiment is. Thx!
Hi,
I have retired from the farm, but be glad to share.
I processed the compost tea for 6 to 8 weeks.
For vegetables, in general, I apply once every other week, until the plants are too tall to fit under the tractor.
Corn, every week, then side spray. I add BTk to it at the first sign of cob leaf.
Hay, after re-seed, after cutting, as well as early spring and late fall.
I used a 200gal tractor mount tank, pto, with roller pump. I attached a 4’ expandable boom (to 12’), with spray nozzles.
I filter before I load the tank, and have a filter in the tank. This ensures the nozzles don’t get clogged.
Gerry