Are there worms in the soil when you turn it over, or water hard?
I have found that cow manure can be too hot for plants (and worms) the first season. It often has to cook down a season to be fit for plant growth. 40 lbs is quite a bit, I usually suggest an half cup per cubic ft of soil. Then you doubled down and added another 80 lbs of manure. High nitrogen burning the plants is a real possibility here. If that’s the case it should be perfect next year.
Also, topsoil is a great starting point for above clay or rocky hardpan. Great for contouring a yardscape or flattening out a hillside but, it also is VERY prone to compaction. It’s the main reason most do not recommend it for container or raised beds without adding lots of loosening amendments to fight compaction. Especially with 120lbs manure, which I find also is prone to compaction. I don’t think the small amount of potting soil (fluffy) would be enough to prevent compaction. I bet if you fluff it up with some leaf litter (falls for free in the fall) and chipped wood and or char it would gain more bulk and loosen up. Does the soil clump together in tight shovel full; or does it loosely run off a shovel? Specifically after it has sat undisturbed a couple weeks?
Crushed lava rock would work well too, or perlite. But the perlite would not last as long as the lava rock, and it tends to float up in the soil with watering/rain over time. More so outdoor when it rains hard. Personally I would add all these to what I normally see sold as topsoil to prevent compaction. If it compacts then there is not enough oxygen for good plant roots on annual crops. Tree roots are different. Compaction would also prevent the manure from cooking down properly to be less “hot” like it would normally in a loose pile. If there is lots of dirt clods, or it’s easy to make dirt balls (like snowballs) then the soil is probably too compacted. Hope that makes sense.
I second the soil slurry test to make sure it’s not something obvious. High N could easily be all that’s wrong from the cow manure not cooking down yet. Especially if you live somewhere without much rain to flush and mix it. Or lack of Ca (or Mg) as @borialis suggested. I love KNF methods myself, so second that and love the suggestion. But that’s another thread ha.
Where did you get the manure also? Less likely, but a surprising common thread topic on my fruit forum is contamination. Many leaders/moderators there have been very vocal on my fruit growing forum about broadleaf herbicides being used on hayfields as a common practice now. The problem is that the poop from these horses and cows fed grass from herbicide treatment is no good for the garden. Farmer is like awesome, no broadleaf contaminates in my hay, it’s worth more. Or a cattle farmer will buy bulk hay and doesn’t know it’s been herbicide treated; broad leaf contaminated hay is often deemed worthless because some of the seeds and weeds can irritate or get lodged in cattle/horses. So I am told anyway…. Then think nothing of it and pile the manure into the manure compost pile. Basically, all the fruit growers suggest sprouting a handful of pinto beans or green beans in a cup of any grass eating manure product before spreading it. If the beans don’t sprout, or grow twisted and gnarled, then it it likely contaminated. This is something I would have never thought of myself.
Here is a quick cut and paste from the fruit forum:
Licensed sprayers please weigh in.
So basically hay, grass clippings and manure can contain ‘persistent’ herbicides, which, even after composted can kill or distort growth in fruit trees, garden veggies, potted plants, etc. Their half-life is about 18 months. The active ingredients of greatest concern are picloram, clopyralid, and aminopyralid because they can remain active in hay, grass clippings, piles of manure, and compost for an unusually long time.
Apparently the instructions for these say that whatever is sprayed with these ‘persistent’ herbicides is not to be used for composting (for just these reasons).
*Anyway this problem is showing up in backyard gardens. *
So, where does the responsibility lie to inform people about these so that doesn’t happen to us? I called a local supplier of compost and he was totally unaware of the problem. What’s more, his attitude was more like, “Well, we’ve never had that problem. We can’t send every thing we get to the lab. (Let us know if it causes you problems.)”
For now, it looks like my only recourse is to get a small sample, plant some beans in it and see if they get distorted growth. I’d like to convince my local guy to at least ASK his suppliers (he wouldn’t give me the info so I could ask), but maybe, if the law says something about this it will motivate him. So that is my question.
You get the idea. Yikes. Just something to think about.