I've had an urban food forest for 4.5 years now. It's under a 1/4 acre in north east Fl. It's a well established system in production.i am recently having problems in my annual gardens....
They are no-dig. Never been tilled. They started off as a sheet mulch. I grow cover crops amongst my annual veggies along with other herbs and flowers. Every time in plant a new plant, the hole gets filled with high grade compost I make, and so does the the immediate area around the new plant. The soil is Always mulched with straw or mulch hay. Lately I've been using chopped oak leaves because they are free. The native soil here is a mineral sand with very little if any organic material. Super low in Nitrogen and high in P and K. Now, after 4 years. I'm high in Nitrogen and low in Potassium with a decent amount of Phosphorus.
I make super aeratedcompost teas very similar to Elaine ingham of the soil food web. Nowadays ,the soil looks nothing like mineral sand but super dark and soft and full of worms when it's raining, when there are dry periods, the soil gets very hard on top, kinda crusty and dry. It's as if it becomes somewhat hydrophobic as well. The structure when dry looks like hard dry little balls and kind of baked looking even under a nice layer of mulch, and you actually have to bust thru the top layer with a small spade to plant. I read somewhere that lack of clay and lots of green manure (constant chopping and dropping) can cause a waxy kinda exudate to form and make the soil somewhat hydrophobic. I never pull up plants ever from seasonal veggies, just chop them at the soil line and leave the roots down there to rot, add more compost mulch and plant. The difference in texture and tilth between rainy periods and dry periods is shocking.The plants are slow to grow but turn out healthy in the end but I believe production is being affected. slow growth, more prone to insect damage etc. I've been gardening for a long time and thus one has me completely stumped. If you would like to see a tour of my project here's the link on YouTube.
Any help from you permies out there would be amazing, thank you sooooo much!!!
I had seen your YouTube video a while ago and was wondering if you would eventually find your way here.
The problem you describe almost sounds like you have a clay soil. Is it possible that now that you have changed the soil with all those additions, subsurface clay has risen to the surface, maybe from those "scattered thunderstorms" that open up and drop 8" at a time? Do you have any muddy water that accumulates in your garden? Clay is never too far away here in the southeast, so it may have snuck in on you and you are now seeing the effects of it.
What is your soil calcium like? If it is low (blossom end rot on tomatoes is a sign of that), then you may be getting hard crusty soil when the clay dries out. The solution to that is to add calcium, and the cheapest way to do that is to scrounge up pieces of scrap drywall at building sites and work that into your soil.
This area has virtually no clay, but I hear what your saying.." It sure does mimic a clay like issue. also when you water heavily, it does not wet evenly and what does get wet gets kinda mucky. It's weird after a rain sometimes you go dig around and there's dry spots in the bed like it did not even rain.
sounds exactly like my allotment site soil. I have 2 plots, one has a clay subsoil and one a sandy stone subsoil with sandy stony soil above. Both cap (grey colour and hard as concrete) in the way you describe with exposure to the coastal wind and a dry spell. Like you say, with a bit of rain it improves. I have found that if I mulch the soil well then it mitigates the sun uv rays and wind causing this. I am surprised to hear it still caps despite your mulch.
You need to direct sow, Fukuoka style at the right time when temps are good and rain is due, or just keep the surface wet with water can to get germination, then mulch. Also transplant plugs in moist conditions.
I found herb and fruit bushes, gooseberry, raspberry loganberry and fruit trees heavily mulched the easiest to workwith on soil like this, then as they shade the land and self- layer - propagate the edge is created and soil improves, shade and wind protection, strawberries under.
Potatoes will do ok in low N soil, grow brassicas in high N. The weed species you have self seeding will indicate a lot.
OK, after reading this article and then this article, I think I'm getting an idea what the problem is: in all the biomass you have been adding to the soil, you have put in more natural waxes than natural surfactants. Probably an easy thing to do if you aren't paying attention to that balance in the first place and you have an easy source of waxy plant materials (like palm fronds, bamboo, magnolia leaves, etc.)
I would say that you need to get some more natural surfactants into your soil --like soapnuts. Are there any plants in your area that have a soapy character to them? Their plant juices easily foam up when you stir them up in water? Those would be the ones you want to be using in your mulch.
Another thought is that you may be over-aerating your compost teas. Some bacteria and yeasts produce natural surfactants and can break down these plant waxes, but yeasts do their work in low oxygen environments (like brewery vats). How about after you have your compost tea aerated (to get rid of the anaerobic pathogens), you add a bit of molasses or other sugar and pitch it with some bread yeast and let it sit a couple days? If it gets a beer like head on it, you know you have a yeasty culture going and use that to treat one of your dry areas.
These are just a couple of initial thoughts I have. However this is a very interesting problem, and I think I might be having a bit of it too. I can tell I am going to be doing a lot more reading on this subject.
Eli, I had a similar problem when I first got into vermicomposting and tried to pot houseplants in 100% vermicompost, with no soil. I wonder if the organic content of your soil -- at least near the surface -- is too high. What started out as a great thing in your first few years in that location may have gone too far too quickly for the plants' comfort.
the observation that the soil is workable when moist and baked pan when dry means the soil moisture changes significantly. N as a measurement is just a snapshot. Yes there are lots of worms feeding o nthat mulch, no surprise, but when the soil dries out the worms go. Sounds just like my plot. The wind and sun causing this imo. Need to shade the soil more with more organic matter, ideally the weeds that grow there, as they will naturally restore any imbalance. Gaia will heal herself.
Bend post Above makes sense to me. The top 6" of soil definitely looks like straight up worm castings (you would think this would be a good thing right?) castings are sticky and when they dry out the become hard and hard to rewet, kinda sloppy and just not a good structure. So what to do? How do I make this too 6" soft with good structure all the time?