S Bengi wrote:5% bio-char is best. Just mix it in the top 12 inch anyhow you can, probably while planting veggies, over a couple years. Unless you have some heavy machinery.
Another idea is to build tiny swales/hugel on contour to slow water down, went you do have rain events, and also to grow your own chop and drop mulch.
S Bengi wrote:I am really interested in Florida soil.
The easiest "fix" would be to cover everywhere with nitrogen-fixing plants, dutch clover should be in the mix.
The best solution would be to get your hand on some bio-char.
Mulch is almost pointless, because you will have to import it ever season. and on a larger scale that is expensive.
You can also plant drought tolerant cultivar/species.
If you can dig 4ft and hit the sub-surface water table you would also use it to continually water your garden, I would not recommend this though.
Now that it is "winter" plant a few daikon radish, they might help with the sheeting that you mention.
Alder Burns wrote:First thing I would do is to dig a test hole, or several, around the property, especially where you see water running or standing after a rain. It shouldn't do that in a sandy soil like you describe. I've seen a sandy site near Gainesville suck down four or five inches of rain in a summer storm of a couple hours' duration; no puddles, and certainly no runoff! Something tells me there's a hardpan of clay or maybe limestone not far down. If you find it less than three or four feet down, you may want to see how deep it is and punch through it wherever you intend to plant a permanent tree.
I would consider biochar as well. That soil and climate will cause amazing quantities of mulch, manure, and any other organic matter to just disappear, and you will always have to be importing it in quantity from off site, indefinitely, if you want to see an impact on soil fertility and moisture holding capacity. The biochar process locks some of the organic matter up in a more durable form so it's effect will last much longer.
I would guess the sinkhole issue is a larger-scale problem, either natural or perhaps exacerbated by groundwater withdrawals, and that swales, hugel beds and the like on little over an acre isn't going to impact it much.