BHU Day Eight - Diggin' in the Dirt...
This morning I spent some time before class preparing my personal plot for planting out my sweetcorn seedlings. I made holes in the pea straw mulch down to the soil and added a bit of compost to each hole, which was all I had time for before 9am.
The morning's class, Plant & Sow, was out in the great outdoors. We planted out yams in deep furrows, placing the yams in the trenches before lightly covering them with soil scooped from the raised mounds either side. Unfortunately the yams we were using had sprouted way beyond what they should have been (yams can be chitted like potatoes, though unlike potatoes you cover them in a thin layer of coarse sawdust) with long stem growth and copious leaves. This and their mat of roots made them difficult to untangle and they often broke. What was left on them was so overgrown it will probably hold back the plant's development a bit as it struggles to maintain its stem and leaf growth while it establishes itself. Ideally, we learned, yams should only be chitted to the point of having shoots of a couple of inches or less before they are planted out. It will be interesting to see how they go.
(By the way, what New Zealanders call a yam is not what the rest of the world knows as a yam. Overseas, yams are more like a sweet potato whereas what we call a yam is in fact a South American vegetable called oca - not to be confused with ocra, completely different - which is a part of the oxalis family.)
We were going to plant out potatoes as well, but we ran out of space so they will have to wait a bit. We then had another practical assessment, this time in preparing soil for sowing carrots. Of all vege carrots probably require the finest tilth of soil - aside from the fact that the seed is very fine, their tap roots are easily bent or completely foiled by lumpy soil. Thus we forked our patches a good fork's depth, breaking up large clods with the tines. We then broke the soil down to a finer consistency to about a finger's depth, before using hands and rakes to get the surface to a large-crumb consistency. (Not to complete dust, however - too fine and rain will make the surface solid and impenetrable.)
The end of the morning saw a quick rundown on the care of the unit's tools (which should of course carry over to our own... guilty, am I!). It's easy, really - give the tools a quick brush with a wire brush to get the dirt off, and then push the ends into a bucket of oil-soaked grit. Sharpen as necessary, just taking any burrs off - you don't want to grind your favourite spade away to nothing too fast!
Homework for the morning was to define and differentiate between a false seedbed and a stale seedbed.
False and stale seedbeds
The false and stale seedbed techniques are based on three ‘golden rules’:
* Tillage (cultivation) promotes weed seed germination;
* Only 5 to 10% of weed seeds in the soil are non-dormant and able germinate at any given time, but those that can, mostly germinate quickly;
* The vast majority of weeds only emerge from seeds in the top 5cm / 2” of soil, and most typically only emerge in significant numbers from the top 2.5cm / 1” of the soil.
This knowledge can be used to eliminate many, if not most, of the weeds that would normally infest an annual crop at establishment. This is done by creating a planting tilth but then delaying planting so that the weeds germinate and/or emerge before the crop and are then killed either by further tillage, thermal weeding or herbicides. The former is called a false seedbed, as the original seedbed is not the true final seedbed, i.e., it’s a false seedbed and the latter a stale seedbed as the first seedbed has aged, or become ‘stale’ by the time the crop is planted and/or emerged.
The two diagrams below show the details of how false and stale seedbeds work.
False seed bed: A seedbed is prepared, weed seeds in the top 5 cm / 2” of soil germinate and then emerge, the soil is then re-tilled (cultivated) with the minimum disturbance necessary to kill weed seedlings, the crop is then sown, germinates and emerges from mostly weed free soil.
Stale seed bed: Final seedbed is prepared, weed seeds in the top 5 cm / 2” of soil germinate, crop is sown, weed seedlings emerge, immediately prior to crop emergence weed seedlings are killed by a thermal weeder, crop emerges from weed free soil.
Each of these techniques has a component that is critical for its success. For false seedbeds re-tillage must involve the minimum depth of tillage necessary to kill all weedlings, and must be less than 5cm / 2” otherwise non-dormant weed seeds could be brought up from lower soil levels which then germinate in the crop. For stale seedbeds the thermal weeder should be used as close to crop emergence as possible to get the greatest benefit which means it needs to be both fast and effective as the time-window for successful treatment can be very short, e.g., hours.
In the afternoon we delved into the mysteries of worm biology.
Strange creatures. Cool. Very cool. But strange.
For instance, worms have five hearts. Some worms tunnel sideways, some vertically. Like birds, worms have a gizzard in which they grind up their food. The saddle or clittelum (the thick bit part-way down a worm) denotes maturity and is used by the worm to mate. Worms can reproduce biparentally or uniparentally (it doesn't always take two!) and can actually take in and store live sperm for the fertilization of a succession of eggs. Mature worms lay an egg a week, from which between 2 and 20 wee baby worms will emerge.
Like I say: cool but very, very strange. Got the worm song on the brain again now. (There's a new sound, the newest sound around...)
Finished the day by planting out my sweetcorn seedlings in their depressions and also sowing Gianni's Holy Climbing bean seeds. They're a rare heritage variety so I'm growing them to perpetuate the seed. (Holy climbing beans, Batman!) I'll be growing these beans up a teepee made from dry old flax flower stems: I don't want to use them in the Three Sisters system on the corn in case it all goes pear-shaped.
The morning's class, Plant & Sow, was out in the great outdoors. We planted out yams in deep furrows, placing the yams in the trenches before lightly covering them with soil scooped from the raised mounds either side. Unfortunately the yams we were using had sprouted way beyond what they should have been (yams can be chitted like potatoes, though unlike potatoes you cover them in a thin layer of coarse sawdust) with long stem growth and copious leaves. This and their mat of roots made them difficult to untangle and they often broke. What was left on them was so overgrown it will probably hold back the plant's development a bit as it struggles to maintain its stem and leaf growth while it establishes itself. Ideally, we learned, yams should only be chitted to the point of having shoots of a couple of inches or less before they are planted out. It will be interesting to see how they go.
(By the way, what New Zealanders call a yam is not what the rest of the world knows as a yam. Overseas, yams are more like a sweet potato whereas what we call a yam is in fact a South American vegetable called oca - not to be confused with ocra, completely different - which is a part of the oxalis family.)
We were going to plant out potatoes as well, but we ran out of space so they will have to wait a bit. We then had another practical assessment, this time in preparing soil for sowing carrots. Of all vege carrots probably require the finest tilth of soil - aside from the fact that the seed is very fine, their tap roots are easily bent or completely foiled by lumpy soil. Thus we forked our patches a good fork's depth, breaking up large clods with the tines. We then broke the soil down to a finer consistency to about a finger's depth, before using hands and rakes to get the surface to a large-crumb consistency. (Not to complete dust, however - too fine and rain will make the surface solid and impenetrable.)
The end of the morning saw a quick rundown on the care of the unit's tools (which should of course carry over to our own... guilty, am I!). It's easy, really - give the tools a quick brush with a wire brush to get the dirt off, and then push the ends into a bucket of oil-soaked grit. Sharpen as necessary, just taking any burrs off - you don't want to grind your favourite spade away to nothing too fast!
Homework for the morning was to define and differentiate between a false seedbed and a stale seedbed.
False and stale seedbeds
The false and stale seedbed techniques are based on three ‘golden rules’:
* Tillage (cultivation) promotes weed seed germination;
* Only 5 to 10% of weed seeds in the soil are non-dormant and able germinate at any given time, but those that can, mostly germinate quickly;
* The vast majority of weeds only emerge from seeds in the top 5cm / 2” of soil, and most typically only emerge in significant numbers from the top 2.5cm / 1” of the soil.
This knowledge can be used to eliminate many, if not most, of the weeds that would normally infest an annual crop at establishment. This is done by creating a planting tilth but then delaying planting so that the weeds germinate and/or emerge before the crop and are then killed either by further tillage, thermal weeding or herbicides. The former is called a false seedbed, as the original seedbed is not the true final seedbed, i.e., it’s a false seedbed and the latter a stale seedbed as the first seedbed has aged, or become ‘stale’ by the time the crop is planted and/or emerged.
The two diagrams below show the details of how false and stale seedbeds work.
False seed bed: A seedbed is prepared, weed seeds in the top 5 cm / 2” of soil germinate and then emerge, the soil is then re-tilled (cultivated) with the minimum disturbance necessary to kill weed seedlings, the crop is then sown, germinates and emerges from mostly weed free soil.
Stale seed bed: Final seedbed is prepared, weed seeds in the top 5 cm / 2” of soil germinate, crop is sown, weed seedlings emerge, immediately prior to crop emergence weed seedlings are killed by a thermal weeder, crop emerges from weed free soil.
Each of these techniques has a component that is critical for its success. For false seedbeds re-tillage must involve the minimum depth of tillage necessary to kill all weedlings, and must be less than 5cm / 2” otherwise non-dormant weed seeds could be brought up from lower soil levels which then germinate in the crop. For stale seedbeds the thermal weeder should be used as close to crop emergence as possible to get the greatest benefit which means it needs to be both fast and effective as the time-window for successful treatment can be very short, e.g., hours.
In the afternoon we delved into the mysteries of worm biology.
Strange creatures. Cool. Very cool. But strange.
For instance, worms have five hearts. Some worms tunnel sideways, some vertically. Like birds, worms have a gizzard in which they grind up their food. The saddle or clittelum (the thick bit part-way down a worm) denotes maturity and is used by the worm to mate. Worms can reproduce biparentally or uniparentally (it doesn't always take two!) and can actually take in and store live sperm for the fertilization of a succession of eggs. Mature worms lay an egg a week, from which between 2 and 20 wee baby worms will emerge.
Like I say: cool but very, very strange. Got the worm song on the brain again now. (There's a new sound, the newest sound around...)
Finished the day by planting out my sweetcorn seedlings in their depressions and also sowing Gianni's Holy Climbing bean seeds. They're a rare heritage variety so I'm growing them to perpetuate the seed. (Holy climbing beans, Batman!) I'll be growing these beans up a teepee made from dry old flax flower stems: I don't want to use them in the Three Sisters system on the corn in case it all goes pear-shaped.