Occultation... what the heck is that!? It's basically a fancy word meaning "hidden" and when applied to a farming sense, it means to cover the soil.
I am practicing no-till farming, and that is non-mechanized. This means I do not disturb the soil through any sort of discing, tilling, or chopping of the ground. I pretty much leave it in tact and add to the top of the soil. A lot of farmers who want to transition to no-till farming think that they need to first till their soil and fluff it up before beginning their "no-till" journey. This is simply not the case, and I am proving it. The 1/4th acre that I am growing flowers on did not have a crop on it for 2 seasons. Rich Collins, Collin's Farm owner, scattered some winter cover crop seeds; however, they were sown late and we're only a foot tall or so by the time I wanted to start working on the land.
I'm going to describe my methods and what I've learned so far. Mostly because it's interesting to document, but also to help any other growers looking to emulate this method. I should say that I did not come up with this myself. Two farms have been my inspiration: Bare Mnt Farm in Shedd, OR and Singing Frog Farms in Sebastopol, CA.
I started in early March dumping wheelbarrow loads of compost onto my flower plot. I didn't bother to stomp down or chop the cover crop because it was so small. I raked the compost out to be an inch thick and this endeavor took me several days to accomplish. In total, I dumped and raked in 113 wheelbarrow loads! When I was done, I noticed some of the cover crop shooting up. My next step was to cover this field with landscape fabric. I wanted it to lay somewhat flat, so I went over the field with a mower and chopped the cover crop. For covering the landscape, I used two different kinds of fabric. This was an experiment within itself.
One half of the field was covered with heavy duty plastic woven landscape fabric. The other half was covered with the flimsy fabric stuff you can find at any hardware or garden store. Both claimed to let moisture and air through. This is important because the soil needs to be aerobic (have oxygen) so that the good microbes and organisms can break down the plant material and incorporate the compost. If I covered this with black plastic, no air or water would penetrate possibly leaving anaerobic conditions where alcohols would be produced, killing life and allowing pathogens to thrive. No thank you! The next good thing about the cover is that it blocks sunlight, thus preventing weed seeds from germinating. The minimum amount of time to leave the fabric on is 4 weeks. I did that and learned some lessons in the meanwhile.
So, I oriented my fabric East-West (mistake #1 because the North-South winds blew up my fabric continuously). I stapled all this fabric down with irrigation staples (mistake #2 because it was easier for the wind to rip them up). I later used those really long specific fabric staples which I should have used from the beginning.
After learning those mistakes, and continually stapling my fabric back down after the wind had strewn it about, I learned about my choices in landscape fabric. The fabric that was the heavy duty plastic kind smothered the weeds beautifully and left a luscious couple inches of topsoil when I removed it beginning of April. The flimsy fabric kind did not smother the weeds. In fact, the weeds grew taller underneath! With the weeds trying to push their way through, I had to purchase more of the heavy duty kind and I just pieced it together on top of the flimsy stuff. Needless to say, that half of the field took twice as long to be prepared. When I was ready to remove those landscape fabrics, I had noticed that the flimsy fabric one was photo degrading! Take my advice and never use that stuff for occultation. The plastic landscape fabric is the way to go!
I should mention that this occultation thing seemed to work! The soil never smelt funky- an indicator of it turning aerobic. The top 2-3 inches were really nice, and almost all of the weeds were smothered! The survivors were bind weed. Grr!
The soil in my plot looked and felt much healthier than the soil directly next to me with weeds that would continually get mowed:
I now had a clean slate to work with. What to do next?
Generally, it would be great to take soil samples and do a soil test. I planned on doing such, but I had so many plants ready to be transplanted and not enough time to wait. So, I also did not broad fork the soil. If I had though, it would still be considered no-till because I would not have been turning the soil. Broad forking adds air pockets into soil which is often necessary to start no-till farming on clay soil. The deciding factor for me not to broad fork was when I slid my Japanese knife effortlessly into the soil. The clay was thick, yes, but it was not impenetrable. I saw worms galore and knew it would be okay to put the plants straight in. So that's what I did. I did rake the top couple inches of nice topsoil from the pathways onto the rows/"beds" so that my flowers would get a little extra fluff.
After planting directly and mulching several rows, I did decide to broad fork and add amendments to a couple of new rows. Again, this farming thing is a great way to do experimentation! The amendments I added were oyster shell, Sul-Po-Mag, and granular gypsum. I was told by another no-till farmer that most soils are calcium deficient so it's good to add that back. I should have done a soil test, however, and am hoping I will be more organized to do that next spring. The plastic landscape fabric is now used in the pathways and all my plants are growing big and healthy! Flowers are blooming and it's looking beautiful out there!