Since methyl bromide fumigation was discontinued in 2014 the strawberry industry in California has sought out new ways to prepare ground for strawberry production. Strawberries are very sensitive to root rots.

One of the methodologies that has come about is ASD (ANAEROBIC SOIL DISiNFESTATION). In experiments large quantities of organic materials like rice bran or corn silage are incorporated into the soil. Then the ground is irrigated to the saturation point and then field is tightly tarped with plastic. The aerobic microbes quickly work on the organic carbon source to the point they use up all the oxygen creating anaerobic conditions. Soil pathogens cannot survive without oxygen and perish. Also plant root damaging nematodes and a lot of weeds are significantly reduced.

I tell you all this because it seems to me this can be easily accomplished in garden plots bringing back to life tired old unproductive garden spots. The tarping time only needs to be three weeks to do the trick.

Another side benefit is the addition of NPK and organic matter to your soil improving its tilth.

Consider taking a portion of your garden space and trying it out. The method should also eliminate potato scab.

Interesting. What quantities are required? I assume it is a ratio or percentage which raises the question of depth needed to ensure taking out all pathogens.

Follow up would be soil type and water holding capability. I imagine sands would drain out to fast.

If you have enough carbonaceous material in a sandy soil it should hold the water. Plus you will tarp the ground as soon as it reaches saturation point helping to keep that moisture there. As far as quantity of material if i recall right between 2-6 inches of material worked in depending on your soil.

There are plenty of references if you google it up.

I'll look it up. Two to six shouldn't be that difficult to round up for an average garden plot.

I'll bet people that try this out will be amazed at how much better that disinfected ground produces.

Just heating the ground by covering it with a dark tarp, to catch solar radiation, should help.

Keith

I've used a heavy black tarp over a old garden and in 6 weeks all weeds were dead, any sprouting weed seeds were dead and the ground was clear, soft and friable...
Any organic matter had been consumed by worms or other soil bacterias...I think 4 weeks would have done the same. I don't know how that compares to the OP info but I never had so many cucumbers out of so few plants that year....and a bumper crop of butternuts.

Getting a field ready for strawberries doing the method. I can't grow Seascape on this ground any more unless I do something drastic like this. Too much build up of fusarium and rhizoctonia from nearly 70 years of growing strawwberries on this ground.

Carl, if you buried the whole infected area with fresh arborist chips and inoculated it with a beneficial fungi you wanted, could that prevent the fusarium fungi and rhizoctonia fungi from getting started in the new medium, so that your strawberries were safe?

Keith

… no profanity

Arborist chips will not break down fast enough to do the job. The best results are with materials that break down fast and create the anaerobic conditions. Even dried molasses works good. Rice bran is used in many places. No inoculation is necessary, the microbial population will ebb and flow according to the substrates. They are already there.

I added 5 lbs of sugar to every row of yard compost you see in the pic to stimulate the microbes.

I was mostly thinking you could just use the arborist chips to bury the harmful fungi deep enough to make it a non issue.

Keith

Very interesting.

My question is what is your method, specifically, of saturating the ground?

Great info! Thanks BP.

I do the black tarp already and it helps a lot with weeds.

During saturation, would it be beneficial to add copper sulfate so it would "soak in"?

I use 5 gallon rainbird sprinklers. Any irrigation system with overhead sprinklers should work.

Copper sulfate would defeat the process. The process is promoting a microbial war with the good guys edging out the bad. At first aerobic populations thrive until they use up all the air. Then anaerobic bacterias take over producing toxic organic chemicals as bi-products which help stamp out the bad ones. Weeds are also severely impacted. After the tarps/plastic mulch is removed (after 3-4 weeks) air comes back into the soil and new plants will thrive.

Field tarped and now I wait for three weeks.

I know you want that plot for strawberries, but would anything else planted there, like in a rotation break the cycle of the pathogens?

Rotation is always your go to in agriculture and for sure it helps. However, some things just can't get free of the particular pathogens that haunt them. For instance, once you have built up high levels of phytophthora in raspberries you can never successfully grow raspberries in that spot again, no matter how many cover crops you till in during the interlude without raspberries.

Much of our ground that used to be in strawberries is now in blueberries and since blues aren't bothered much by the same pathogens that strawberries get they seem to do fine.

My point in this thread is my bet is most garden soils have built up some pathogens that are likely holding your veggies back some even when they may seem to perform adequately. Most people will have their garden in the same spot like forever, pathogens do tend to build up.