|Straw bales with soil topping and drip irrigation system. We eat the dandelions, so I don't count them as weeds... ;)|
My straw bale experiments are finally yielding some results, so I thought I'd pass on what I've observed so far, and give a little update on the process while I'm at it.
I ended up installing a drip sprinkler system to keep the bales watered, but we have actually had enough rain this spring that I only turned it on three or four times. That means my bales didn't get watered every day, but averaged 3-4 waterings a week. There were also a couple of periods in there where they got pretty dry, so I'd say this is a pretty "realistic" experiment in gardening for busy people!
The results are basically in for the different fertilizer combinations I was able to try:
- Blood Meal: Bales reached temperatures of 100-110 degrees at peak, composted reasonably well. There was no noticeable smell, and the fertilizer watered into the bales without much trouble.
- Alfalfa Meal: The composting results seem to be comparable to the blood meal, at about half the cost. One issue I had with the alfalfa meal is that it doesn't water into the bales well. I addressed this by slashing the tops of my bales with a utility knife to make a layer of loose straw about 2 inches deep, then mixed the alfalfa meal in with that. After doing that, the composting really picked up, so I recommend the practice.
- Cottonseed meal: This initially worked quite well, but it seems to have cooled off too quickly. I suspect that there was dust that kicked the composting into high gear, and when the dust was expended the much slower meal dominated the process. I think the cottonseed meal will provide nitrogen for a longer period though, so it may end up being a good choice in the end.
The problem with all of the commercial sources of nitrogen is that, as far as I could determine, there isn't a way to get these materials from sources that follow sustainable practices. Blood meal is a byproduct of factory meat (which carries multiple drug resistant pathogens), alfalfa is almost guaranteed to be GMO and hence soaked in Roundup, and cottonseed meal is dripping with pesticides. This is the sad state of our society -- you can't even buy stuff that will rot without worrying about long term damage to your land, health, and environment. I'm not sure which is the best of these options, but if I were to do it again I'd probably do the urine approach as much as possible, and then try alfalfa to fill any fertility gap. By the way, if the thought of using human urine on your garden makes you squeamish, I'd recommend reading a little booklet called Liquid Gold -- there's a lot of very interesting information in there about just how silly it is to flush this resource into drinking water...
But I digress. I have elected to spread soil on top of all of my bales, as you can see in the picture. I did this because I didn't have time this year to make proper transplants, so I'm going to be direct seeding everything. I figured that an inch or so of topsoil on top of the bales would benefit the seed starting process by regulating temperature and moisture for the little seedlings.
I used "Evergreen" topsoil, at a cost of $1.16 per bag. A one cu. ft. bag will put an inch thick layer of soil over about four bales, so you can calculate accordingly if you decide to try this. I haven't seeded them yet, so I can't report anything about sprouting rates... that'll come in a future post!
In other garden news, I've been reading Introduction to Permaculture, by Bill Mollison (I *highly* recommend reading this book), and there was a potato raising technique in there that I simply had to try out. This is a vertical gardening technique for raising potatoes in limited space, with very little effort. The basic process goes like this:
- Cover the ground in a 3 foot diameter circle with newspaper or cardboard.
- Put up a cage of some sort over the cardboard. I used vinyl poultry netting because it was the absolute cheapest material I could find on short notice. This does not need to be strong, so anything you have on hand that could support a pile of straw will work.
- Put about 8 inches of straw mulch in the bottom.
- Plant your potatoes
Here's a shot of my four potato cages, primed for spuds and ready to go. It took about an hour to put them all together, which is WAY faster than the old dig and prep way. If this works it'll be a fantastic technique to add to the repertoire: