La Bonne Terre

This past week I have been busy harvesting worm castings for this springs crop of soil amendments, soil blocks, and potting soil mixes. It's a painfully slow process, but so worth the work and to boot, even on cold days when the temps are in the teens it's at least fifty five in the wormhouse (so long as the sun is out). On days like today where the outside temp is in the fourties, it just darn near feels like late spring in the wormhouse with temperatures approaching 80 degrees.


I have been vermicomposting for about four years now, trying new means and methods here and there as I go, having started out on the small scale with a couple of totes bought from the dollar store, moving up to 20 of those in what is now the primary turkey shed, and now with 13 4 x 4 x 4 wooden bins located in a 20 x 36 greenhouse called appropriately "The Wyrm".

Vermicomposting is a form of cold composting, a form of composting inherently better for plant fertility since you are not loosing valuable micro-biological life to extreme heat or loosing nutrients as readily via off gassing. There is a trade off in that you can if not carefully choose to feed diseased plants into the bins and the diseases then get passed into the plants that you fertilize with worm castings, however a few things in a worm bin are working on our side other than just the worms. The micro-biological rich humus organisms do a lot to fight off disease, both plant based as well as diseases which can occur in nature and infect humans, couple the work of these microbes with the action of black soldier fly larvae and sow bugs which are capable of digesting and destroying heavy metal particles and disease particles and your good to go!


As you can see above, the Homegrown Worm Harvester talked about on the blog here many times is still being put to good use. Currently I am in the process of harvesting 3 bins of material with a further two ready to go. The material in the bins is close to 95% finished castings, the only issue is that much of this material is still wet which means that once it is run through the harvester it has a tendency to "stick" together in moist balls. There is a solution, but it is, as said above, painfully slow. The first step in harvesting a bin is to create a refuge for the active worms to escape into which can be moved into a new bin, this started on December 1'st 2009. We use bread racks from a convenience store and place new organic material on it moistened down to attract the worm heard into the new material, after a month many of the worms have moved into this material which you can then pick up and move into a new bin. Afterwords I remove the top inch of material into a new bin as well just to pick up some of the worms that were a bit slower than the others, since most of the composting worms work within a couple inces of the top of the compost this method works pretty good, but you will never "rescue" all of them and you'll be surprised at the numbers left in the remaining finished compost.


Since I have not yet found a cheap and convenient continuous flow system the castings on the bottom do have a tendency to get waterlogged so the first thing we have to realize is that there is going to be a "drying time" for the castings. We let them set without water for the entire month of December while the worms are moving into their new bedding, once the worms are moved we begin the harvest. On the first pass through the harvester you only get about 8% of the bulk of the material as harvest able due to the moisture, we usually run one wheelbarrow worth through the harvester three times, pulling off about 15% of the bulk. At this point the other material, which is completely finished but wet, is bulked into empty worm bins where it will set for 1 to 2 weeks while we allow the worms to break it up again without the aid of any water wherein it will be harvested again with a gain from the bulk of 80% pure castings, the remaining material then goes into a new worm bin.

One of the big advantages of the initial harvest is that air is allowed to work it's way into the material that was located in the bottom of the bin and is the most moist. This turns portions of the bin that were a bit anaerobic to material in an aerobic state facilitating the breakdown of the majority of the material that was left undigested as well as accommodating a quicker dry down of the finished material.


Five years ago Kim and I decided no chemical would touch our soil again, creating thermophilic compost on farm and a worm farm went a long way, but there was never enough of this material to take care of all of the crops, for the first year in those five years we will not have to supplement our compost harvest with any bought manures or organic amendments with the exception of course of lime. We currently also have 5 4 x 4 x 4 containers in thermophilic mode of chicken/turkey/ and guinea material as well.

We will use these castings for just about every purpose here on the farm, fertilizer, potting soil, and soil blocking recipes, as follows are the methods we use to produce Bishop's Homegrown "La Bonne Terre" (the good earth) in it's many variations.


La Bonne Terre Soil Blocking Receipt:
We have struggled in searching out a way to create potting and soil blocking mixes completely self sustainably from material here on the farm. It wasn't easy, but we have found something that works well for us.

We use 2 parts worm castings (1 part is roughly four gallons by volume)
2 parts garden loam - Heavily amended clay based soil
1/4 part sand
1/4 cup bat guano
1 cup of lime
1 cup diatomacious Earth

Mixed together well and moistened this holds together as well if not better than any store bought mix or "homemade" mix with blood meal and imported coco-coir (food miles self sustainable guys?) or the non renewable sphagnum. We feel this also makes our plants far more adapted to their future planting than any other method we have ever used, and trust me, I've used all of it. To sterilize the garden loam and prevent fungal disease, weed seeds, and insect damage to plants or seed we use an old wash tub filled with garden soil to which we add 2 five gallon buckets of water and place above a fire on our outside wood pit. We heat it to 160-170 degrees for sterilization purposes. Works wonders and costs nearly nothing minus the lime. This is the same mix we use for potting soil with the exception of adding leaf mold and Forrest dander for water retention as well as gravel at the bottom of the pots for drainage.


La Bonne Terre Soil Amendment/Fertilizer
This is our main fertilizer at this point. In previous years we have added composts directly to the soil along with unprocessed animal manures which have led to many seed and plant pests as well as weed issues. Until this year we have never had enough of any self produced material to create this mix on a large enough scale to feed all the crops including the new orchard crops and raised bed greenhouse crops.

It works like this:
one part castings, 1/8 part bat guano, a cup of lime per five gallons, 1/8 part screened high nitrogen compost (poultry litter), mixed with one cup diatomacious earth per five gallons. The diatomacious earth eliminates seed and root destroying pests. We have found this mix to be perfect for every crop that we grow, some have thought it might be two high or two low nitrogen for some things but we have found the ratios to be about ideal for an already decently balanced soil. We should point out that our soils have been heavily amended over a five year period with probably close to 40 tons of organic matter added if not more, to the entire area of cultivated land. It should also be pointed out that the worm herd gets fed a very diverse diet, mostly composed of high nutrient feed stocks as opposed to bulking material like sawdust and cellulose as is fed to most commercial worm heards, this gives us access to most of the micro nutrients that are missing from most commercial casting mixes as well as access to higher NPK numbers than commercial castings. The last test that was done ran 3-3-3. We also have to realize this isn't a nutrient shot like commercial fertilizers, the nutrients are slow release but they are active and more available to plants than in almost any other type of fertilizer. About a month after planting everything will get side dressed with another dose of La Bonne Terre and occasionally we make a tea to feed to certain plants. I should also point out that last year we placed several bat houses around the farm from which we ethically harvest bat guano for on farm use. This material as well as the castings contain Chitin's, the broken down proteins of the exo skeleton of insects, known to be an insect repellent.