This is about some experimental garden plots my wife and I have been working in since 2014, the first year we grew some of our own foods on Buzzard's Roost.
Our soil, while not solid clay only had a measured 2 inches (5.1mm) of true top soil present, the second horizon was pure red clay mixed with stones, this topsoil was the result of 7 years of laying fallow with primary and secondary inhabitant plants growing as the result of a fire.
We had spent one year clearing the secondary plants (blackberry canes and sumac trees) so we would have space to plant garden plots and orchard trees.
Because the soil was so shallow we determined that straw bale growing was going to be our least invasive, least disturbance method which would let us get food plants growing and producing the fastest.
I decided that this was a perfect opportunity to do some testing and documenting of how soil reacts to such an endeavor.
What we have done is 1. determine where we wanted the initial gardens to lay on the landscape, set double rows of rectangular bales of clean, non-sprayed wheat straw that were covered in 2 inches of spent coffee grounds that were poked into the bales with a round, sharpened stick, and watered every day for three weeks.
Once the bales interior was heating we dug holes to plant in and used a home made potting soil that was 1/2 compost, 1/4 bagged potting mix and 1/4 top soil acquired from an area I was getting ready for pouring a footing for a work shop.
The plants we grew were: tomatoes, broccoli, bell peppers, and beans, these were chosen because we eat a lot of these items.
Plants were all watered in with a 1:12 dilution of fish emulsion and multi vitamins, the vitamins were a 4 tabs to 1 gal. solution prior to being diluted to the 1:12 final mix.
We also double dug and improved the soil in a 4x8 area for growing beets, carrots and squashes.
That soil was amended with 4 rectangular bales of straw and 5 50lb. bags of potting mix, seeds were watered with the same solution as the plants in the bales.
I also inoculated all the bales and the 4x8 "root vegetable" space with mushroom slurries of mushrooms found growing on our land; jew's ear, lion's mane, true turkey tail and boulet's.
All of our vegetables produced quite well that first year, but more importantly, I was then able to study how the soil under the bales had reacted to the bales being in place and growing foods.
The only "additive items" that touched the soil under all the bales was what leached down from the rains passing through the bales, no chemical or other fertilizers were added through the growing season, so the only nutrients were what was there at the time of planting into the bales.
Year one end of summer vegetable production was on November 25th at which time the plants were removed from the straw bales, the tomatoes had put roots all the way through the bales and down into the soil to a depth of 1.25 ft.
The peppers had also put roots all the way through the bales but these roots stopped at just 3 inches into the soil beneath the bales, the beans had mirrored the peppers with their root growth but the broccoli had only sunk roots to about 2/3 the depth of the bales.
One end bale and one middle bale were removed and the soil beneath was checked for friability, texture, mineral content, microorganism types and numbers of organisms per type (not species).
The friability (looseness of the soil complex) was equal to soil samples from a flood plain that was under agriculture in the ability to form a ball but still fall apart when touched. (good friability)
The texture was greatly improved and organic matter had risen from 4ppt to 38ppt. A block was cut out and examined with a hand held 100x microscope and there were 100 micro channels per cu.cm found.
Previous samples had shown 4ppt organic matter and 10 micro channels per cu.cm. This indicates a marked increase in the ability of exchange of gasses and water.
The bales that were removed were put back into place and a winter crop of greens was seeded onto the bale tops, which were watered in with tap water through a hose with a mister attached.
In the spring the bales had decomposed enough as to have collapsed from approx. 2 feet tall down to 1 foot tall with a rounded top structure.
Test plot one had these bales removed and the remaining material was incorporated into the 4x8 root vegetable garden space.
(the root vegetable space had produced good beets but these were small sized, the carrots did not produce well while the squash produced 5 1 lb. fruits per plant.)
Year one conclusions were that by growing in straw bales, set on "virgin" top soil over clay ground, the results will be an increase in depth of topsoil characteristics as a result of the bales being in place.
This is a very timely post because I'm getting ready to do this very thing on a new plot of land in the next couple weeks. I have approximately 80 organic straw bales that have been sitting outside all winter that will be the basis for the new garden area. I have some coffee grounds and I believe I know where I can get a bunch more in the next day or two. Water will be the biggest issue because I don't have a water source on the land yet so I'll be bucketing it in on days we don't get rain, but I'm excited to get started. Thanks for posting this.
Year 2 plots 2 and 3 of straw bale use and soil/subsoil changes due to year long coverage with bales. Starting date:March 5th, 2015
Plot 2 original bales were leveled off because of slumping over the winter making the planting surface undulating. New bales were then installed on top of this leveled substrate of original bales.
New bales saturated with water for 3 weeks prior to spent coffee grounds mixed with year old manure compost then watered another 2 weeks prior to planting due to consistent rain fall, every other day.
At onset the soil tested similar enough to the original plot one year end results as to be considered identical.
A new long probe thermometer had been acquired and was used to check internal temp. of bales just prior to planting, internal bale temps averaged 110f with a low of 93 and a high of 122.
Once again the surface applied amendments were worked down into the bales with a sharpened stick and the bales were kept saturated, both by the initial three weeks of water additions and the spring monsoon like rain events that are typical of the region.
Plants that were transplanted into the bales of plot 2 were cucumber, zucchini squash, Yellow and Red Bell pepper. Each plant was placed in a hole cut and removed then worked in a circular motion to loosen the straw surrounding the hole.
Each plant was placed and compost enriched "potting soil" was then packed in around the root ball, which had been loosened and roots tweezed out, and watered in with a 1:12 vitamin/multi mineral solution.
At the end of planting the double row of bales all plants were watered in again with the same solution to insure complete contact with the planting soil and bale straw.
pH of bales was checked with a fisher scientific model 310 pH meter and probe, initial pH was found to be 6.8.
At the end of week one plants growth at growing tips showed they were establishing new roots and 2 tablespoons of Sea-90 was sprinkled around the rim of each planting hole.
Bales were checked for moisture content and no water was added.
Plants had put out 2 sets of new leaf growth and had grown vertically 2 inches.
No additions were made to the growing medium, moisture content was checked and no water was added.
Plants grew vertically 3.5 inches and the beginning of secondary stems were evident on the pepper plants, cucumber vines were wrapped into circles so they would remain on top of the bale vine growth was 1 foot and blossoms were found to be starting to form.
Zucchini leaves were measured at 4.5 inches width, no blossom stalks were found to be forming.
Soil sample probe (rod opening capped end type) was used at a 30 degree angle at the base of each bale's mid point and a plug sample was taken of the top 5 inches of soil, insertion tip cap was kept closed until stiff resistance was felt at the T handle at which point the cap was opened by activating the rod,
Probe was then "screwed" into the soil to be able to retrieve a solid sample core, when the required 5 inch depth was measured on the probe tube the cap was closed by rod activation and the probe removed.
Sample cores were expelled onto saran wrap then rolled and ends folded and tied to seal the sample for transport to the lab for testing.
Peppers had grown another 3.5 inches in height, blossoms were observed opening leaves were 3 inches across at the base and secondary branches were 3 inches long .
Zucchini had male flowers forming at the 4th set of leaf/stalk junction, no female flowers were found to be forming yet. Leaves were 10 inches across.
Cucumber vines were hanging over the edge of the bale almost touching the ground, four flowers were found on each plant but no baby cucumbers were forming yet.
Bale moisture check was performed and 1 gallon of plain water was applied to each bale. Ambient temperature was 78 degrees, humidity was 66%
Weeks 6,7,8, no tests were performed because of being away from the farm
Week 9; all plants growing at a rate of 1/2 inch per 24 hour period, bees are busy pollinating flowers of all tomatoes, cucumbers and beans which are prolific in flower production.
A core sample of the bales was examined for each bale and found to have four species of mycelium and 15 species of bacteria. The bacteria are congregated around the root systems of the plants and at least two of the mycelium are ectomycorrhizae.
Minerals lacking were augmented with a granite dust spread over the tops of the whole bale structure and lightly watered with a rain wand to get the dust down into the bales to prevent wind blowing it away.
Harvest of the tomato plants yielded 30 ripe fruits from 4 plants, fruits from each plant were sampled for lab work to list out the nutrients, and taken to an outside lab with better equipment for performing these test.
Beets in the soil bed were thinned for the second time with the pulled beets measuring 4cm diameter.
hau Lina, the vitamin solution is used at the time of transplanting, it helps the roots recover from the shock. The fish emulsion is applied a week after transplanting and once a month for two months after that initial application.
Bales are great for this regimen since any nutrients not captured by the soil and straw will make its way down to the soil below.
Continuation of year 2, plots 2 and 3;
The soil below the bales was core tested and microscopy was performed.
1cm yielded 2000 bacteria of five specie types and 7 fungi species had multiple strands of hyphae growing through all core samples, this indicates that the soil is becoming well populated.
Mineral quantities tested higher than prior to bale placement quantities, partly because of the bacteria and partly because of the table spoon per plant of sea-90 that was used at week 4.
Without any uses of compost teas the microorganism counts have risen 275% over year one in the soil, bale activity seems to remain constant once the bales are decomposing internally.
continued soil improvement is anticipated through out the rest of this growing season and bacteria counts are expected to rise to 5-7 thousand per cm along with an increase in fungal strands.
Bacteria have been observed traveling along the fungal hyphae which may be due to exudate emission by the plant roots, further testing should show if this is indeed the case.
Thanks for the informative thread and your diligence in collecting the data. I will be trying this next year on my farm. Too busy building a house now to do much gardening. I would be interested in your opinion of laying our the double rows in my garden on contour since I have a bit of a slope. Over time with successive years of bales would this become a modified swale system? If I am following your method the previous years bales would be leveled to accommodate the new bales each year? How many years do you think it would take for the native soil to convert to a non-bale system? Here in Tennessee I have very similar soil. Due to the rocky soil tree planting and post hole digging is a challenge.
Personally I have become a fan of making a woodchip bed about a foot deep and dig fertile holes for planting (tomatoes in my case). After planting I inoculate with wine cap mushrooms, cover with straw and wait a year. My 1 year old chip bed has, thanks to the wine cap spawn, has thoroughly broken down the chips and is almost in condition for direct planting small seeds. I am growing peas directly in the chips at this point and I will be planting beans as well.
Hopefully by next year the wood chips will be converted into a high quality bedding, but in the meantime I am growing squash where the tomatoes grew last year.
I have a new chip bed where I am planting lettuce, radishes and spinach—small seeds—into fertile trenches. I will inoculate this bed with wine caps shortly and with luck by next year I will have a perfectly good garden bed.
Long story short, I use fertile holes and trenches until the wood chips are sufficiently broken down.
I am using the exact setup you asked about, bales setup on contour to create a swale system through the bales becoming the berm.
I set up bales 2 wide and however long I want the swale to be in the end.
If the bales are nice and tight they will last two years of planting at which time they will be flat all on their own and new bales are just set on top of the old ones.
If the ground slightly sloped I just set the bales and let them lean with the soil surface, by the time the bales have deteriorated enough to be replaced, they will be fairly flat on the surface or you can use a garden rake to level them on top.
If you get bales that are pretty loose to start with, these last one year at which point the rake comes out and they are leveled prior to setting the new set of bales in place.
It takes me three sets of bales to develop the swale/berm profile enough that it functions as if it was a dug system.
Once I have set a line of bales I wet them all the way through then I put on the coffee grounds so that they are about 1 inch thick over at least the middle third of the bale width and water that in gently or let the rains do that work for me.
I've found that the longer you have the bales in the "Prep" mode, the better they preform the first year of growing. This years bales were set out in January and we started planting in them at the first week of April.
I did water them at the beginning but since that first week only rain has added any moisture to the bales.
The two ways to plant in bales are; 1. dig holes for each plant, add some good compost mixed with soil then plant the plant. 2. dig out a trench the length of the bales and fill with the compost/soil blend then plant in the trench, leave about 8 inches of bale at the ends to hold the soil in place.
If you want to really speed up the quality of plant growth you can add some mycorrhizae mix as you plant the plants then come back a few weeks later with a compost tea spray for the bale tops.
Usually I have found that the fungi and slime molds that come from the coffee grounds do a good job of inoculating the bales with mycelium, as well as the spores that land on the bales throughout the growing season.
The bales will slowly discolor on the exterior but the interior will turn black and have many white mycelium threads running through it.
If your plant leaves are showing missing minerals, a couple of tablespoons of sea-90 or a similar non-purified sea salt should take care of the issue.
Can small berms be made with wood chips? It is a minor slope area less than 5 degrees. Similar to what you did with bales? I have been making raised beds over large portions of my land and now I know where the water flows because of the signs left on the wood chip floor. I would like to start trapping the water long enough so it drains into the soil.
Would it be better to mix anything in with the wood chips, like sand, expanded shale, compost, peat and a little dirt? Plant some clover on top so the roots hold it together longer? My wood chips often have fungi growing in them when I finally get them to where they need to be.
Lessons in life will be repeated until they are learned.
I can't think of any reason that would prevent making berms with wood chips, the only issue would be washing away of the chips by the water flow. The bales work because they have weight and are usually bound with bailing twine to hold them together.
If you experienced any washing, you could try using some sort of back stop, it would only need to be tall enough to stop the water flowing under and floating the wood chips.
In our hog area I use the rocks the hogs have rooted up to make berms that are in the 4 to 10 inch range in height, I have to also make them at least 2 feet wide so the hogs don't drag the new berm away if they walk over it (which they seem to delight in doing so the extra width stops them from trying).
Thanks Dr. Redhawk. I have a lot of concrete blocks that I use to make raised beds and once the beds have a lot of root growth throughout, I remove them to make another bed. I can use these as a backstop for the chips. I have started to make some channels and use this idea to make a couple of swales that should be easy to remove if I ever sell and move to a larger lot. Converting my lawn over to a fruit jungle.
I do the raised beds because of Karst topography and underground streams that show up for a while and then move on to another spot. This seems to work and was a solution after losing a couple good trees to drowning.
Lessons in life will be repeated until they are learned.
I'm trying to start a garden in an area formerly used as a cow pasture that is planted with bermuda.
Would this method work on clay soil currently planted with bermuda? Should I put a layer of cardboard under the bales?
Or in the case of bermuda, would it be better to till then cover with black plastic for a few months?
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