I made a couple of NDVI images of the beans which had been greatly improved using compost compared to those grown without. The principles of NDVI as based on that
Generally, healthy vegetation will absorb most of the visible light that falls on it, and
reflects a large portion of the near-infrared light. Unhealthy or sparse vegetation reflects
more visible light and less near-infrared light.[ref]Understanding the NDVI PDF[/ref]
Knowing that, it’s possible to see in the NDVI image that the compost-grown beans do seem to be reflecting more IR relative to visble light, I find this easier to qualify from the greyscale image Continue reading “NDVI investigations of compost-enhanced crops”
Last year we made compost and compost extract for use in the polytunnels. The extract was also looked at with the microscope. Most of the compost after making extract was used in polytunnel which has tomatoes in it. These look healthy and were praised by another local gardener, but there’s no control. However, we did have a control on the extract applied to the beans in another polytunnel.
If you look at the picture at the head of this post, on the RHS of the picture is the control. This is what we would have grown normally.
in the middle on the top you can just see a blue ribbon which is where application of the compost extract stopped. On the left are the plants where compost extract was applied to the ground, it ran out at the blue ribbon point. Same plants, same time planted, and the same set of seeds. The difference in vigour, height of growth and yield is remarkable and clearly to be seen. Continue reading “Remarkable win on beans with compost extract”
We are going to do some experiments trying to lengthen the day light-wise on salad leaves, getting them jump started to harvest earlier. Britain is a funny place to grow things, the maritime microclimate means it is relatively warm for the latitude. The growing season can be limited by temperature and/or light. Because we are warmer than typical for the latitude there might be some mileage in tackling light. Britain is basically warm and dark from a plant POV. You tackle temperature using a greenhouse, or in our case a polytunnel.
the mounts let us set the lights higher as the seedlings growplant-level view
Trouble is we have no power on site, so this is an LEDs and leisure batteries job. It’s easy enough to turn off the lights once real light is bright enough[ref]I went off this after reading the Philips material and some other web research in favour of a straight time switch[/ref], but a leisure battery gets trashed if I just let it run down too much, ideally I want to pull the load once it’s down to 11.5 V or so. This gets complicated when you have something charging the battery too, but the whole point I am trying this is because we are around the Winter Solstice so there’s not much light about. So the only way that battery is going to get charged is for it to be recovered, changed out, charged and reinstalled. So once the battery gets lower than 11.5V it’s time to pull the load and keep it pulled until the battery power is reset. Even if the battery level creeps up above 11.5V off load that load should still stay off.
the battery, timer and low-voltage cutoff
What LED colours?
LEDs give the opportunity to favour certain wavelengths – leaves are green because plants don’t use much green, which gets reflected back for us to see.
Red and a little blue seem to be the principal colours used in this industrial Yorkshire LED4CROPS facility
Red and blue seem to be the light colours wanted, with more blue in the initial stages, red for the flowering stages. This seems to be starting to be big business, though I do somewhat wonder at the approach taken. Many of the woes of industrial agriculture stem from its arrogance in separating variables and hitting one particular aspect for all its worth – chemical farming addressing nutrients but destroying soil micro-organisms that have cycled nutrients for millennia resulting in veg that increasing lacks trace elements (the McChance and Widdowson The Composition of Foods longitudinal research) and tastes of bugger all being one example. There’s a difference between trying to push things a bit but still working with natural light and growing stuff in windowless warehouses and hubristic statements like
We are beginning to understand that growing crops in this way can improve their quality in many different ways, from their shape and colour to their flavour and nutritional value. We could, for example, increase plants’ vitamin C content.
Hmm. Maybe if we could answer why the mineral content of industrially grown foods has been falling and often tastes bland compared to 30 years ago or more I’d have more confidence in that statement. Can’t argue that yield has gone up due to industrial farming, but quality?
Back to the LEDs – we will always be short of power, though at least we are growing plants that can grow okay in the UK – salad leaves, just trying to advance them. Many people who use grow lights are trying to grow five-pointed leaf plants that aren’t typical UK horticulture. We should be having an easier job 😉 We are dealing with seedlings, which also makes life easier – we can get the LEDs much closer to the plants, a few centimetres. The RHS publication Science and the Garden: The Scientific Basis of Horticultural Practice seems to support this on page 211 which is just as well given our power limitations
This is easy enough because I am looking for the battery voltage to drop below 11.5V after which I will shut off the lights. By putting this on our RF network I get the status reported back, and by using the Ciseco RFu I get an almost-free arduino chip so I can throw in a temperature monitor, as well as manage down the shocking 7mA quiescent current of the Arduino by sleeping it most of the time[ref]the ATMega 328 does have a watchdog timer but it’s a slight git to use with the Arduino[/ref].
Measuring the battery voltage depends on the reference voltage which is supplied by a KY5033 linear regulator (Texas LP2950 fixed 3.3V) There are actually pretty good, within 2% across -40 to 100C, which is better than the 5% tolerance of my resistor divider, which I want to arrange so the output is 3.3V/2 when I apply 10.24V, which can be done with a 115kΩ top resistor into a 22kΩ lower resistor. The total string draws 12/137 mA which is about 100uA, and the source resistance is about 18k, above the 10k recommended in the datasheet but I am only looking for about 8 bits of resolution. I could put a capacitor across the ADC input to improve that, but I can live with the error.
Jeelabs shows I could take this a lot further, but it’s good enough. I will be powering a string of LEDs drawing about half an amp for half a day or more, so as long as someone gets to the battery in about a week after it shuts down I will only have drawn another 0.02Ah from this cause, plus a bit more from the temperature and RF reporting for a few seconds every 15 minutes.
system overview
Results – failed
because we couldn’t keep the power up long enough, it just needed too many changes of batteries. We were also fighting the fact that the lighting blocks some of the daylight, so it was probably overall a reduction of light.
I have had success using three 11W CFL lamps about 60cm above some seedlings at home where power is available, so the idea of manipulating light is sound. But it’s not low-power, unfortunately, even with LEDs.
Failed attempt 151024. Compost heap centre temperature against date/time. The flatline is an artefact of the lost signal being held at last known good value. Despite saying “outside temp” the blue line was a probe in the heap.
No more details.
Joanne’s note Oct 2016:Like our previous failed attempt, we just wanted to keep it in here for completeness (unlike big corporations, we don’t hide results that don’t support our aims!) and to make it clear that it has been hard work refining our compost making art to meet the Ingham spec! In retrospect it will have been getting cooler in October, and we hadn’t started wrapping our heaps in mypex woven black plastic for insulation on our exposed site. Also, we probably hadn’t added enough nitrogen or chopped the material up enough which was the key to our subsequent sucesses.
Failed attempt 150912 – Compost heap centre temperature against date/time. Despite saying “outside temp” the blue line was a probe in the heap.
This heap was made using the hardware cloth mesh netting technique. In retrospect September is far too late to have tried out that approach, the autumn winds dried this heap out after a promising start. We need to shelter this sort of construction more than the more enclosed black plastic bin.
dismantled heap on the 26th October showing the construction using hardware cloth
On our site this construction is going to be more a late Spring and Summer sort of thing. The failure mode is drying out, as the chart shows the core got hot enough the first and even the second time, but couldn’t sustain the burn. The large discrepancy between the temperature probes also points to unevenness.
Joanne’s note Oct 2016: Probably too discouraging! Just wanted to keep it in here for completeness, and to make it clear that it has been hard work refining our compost making art to meet the Ingham spec! In retrospect it will have been getting cooler in September, and we hadn’t started wrapping our heaps in mypex woven black plastic for insulation on our exposed site. Also, we probably hadn’t added enough nitrogen or chopped the material up enough which was the key to our subsequent successes.
The Seed Saver’s handbook says beans are easy to save, so it seems a good idea to start out with them, in this case some Sutton Dwarf beans. The idea if you leave them to dry in the pods and then save the good ones. Beans are an easy win as they adapt over the generations to the local conditions; they don’t use insects for pollination and the book says the gene pool is kept wide to allow self-pollination.
Right off the bat the book says that
The first pods to form are the best for seeds. They are to be found at the base and are larger than subsequent pods, Allow these pods to dry on the bush, and choose those from the most vigorous plants. Such refined steps cannot be taken on a large scale where a whole field is combine-harvested and threshed.
Well, we don’t have a problem picking seeds out of the combine harvester we don’t use 😉
the good bean seeds
The guys that wrote that book are Australian, and I guess they don’t have a problem with saying you need to store seeds at a relative humidity of 5%.
Closing the conservatory door at about 9pm was a good move, though I am a long, long way from 5%!
So I am writing on the evening of what has been a reasonably warm sunny day and I see the RH starting to skyrocket to 50% by 10pm and realise that I need to close the door to the conservatory because the dew comes in the evening as the sun goes down, not in the morning. 5% is going to be a tough call in the UK, probably involving silica gel. Interestingly the Seed Saver’s Handbook says good airflow is more important that high temperature, and it should not go beyond 35C anyway.
long bean pods give the best results
They’re right about those lower pods – long beans are definitely the place to go for the size of the seeds. You have to be pretty discriminating about the seeds, however.
The NoIR Raspberry Pi camera comes with a blue filter to do near infrared photography – the blue filter ices the visible red but passes near IR which records as red, apparently.
NDVI image of something in the polytunnels. Should have made a not of what this plant is 😉 Anyway, more red and going to magenta white overload=more photosynthesis
There are two approaches to measuring paramagnetism that seem to be common. One is to use a balance to measure the slight attraction to a magnet – put sample in a balance, apply magnetic field, look for difference in weight of sample using a Gouy balance or use a torsion balance to observe the attraction in a horizontal plane which takes out the static weight of the sample.
The trouble with these two is the attraction due to paramagnetism is weak compared to the weight of the sample – these are lab bench instruments and the electromagnet consumes a lot of power. Although taking samples of soil is easy enough to bring back to the lab, one really shouldn’t be taking a hammer and chisel to ancient monuments to get a sample for a Gouy balance 😉
It’s not really right to go chiselling a lump off megaliths that have survived thousands of years to insert into a Gouy balance…
The other way of measuring volume magnetic susceptibility is to stick the sample into a coil and measure the inductance – with a different configuration of the coil as a search coil it can be used to measure susceptibility at the rockface.
This is using Elaine Ingham’s microscopy techniques to investigate thermal compost – some of what I saw. I am at an early stage of being able to do this, so any errors are mine and not Elaine Ingham’s 😉 The principle is to classify organisms by their morphology – aerobic fungi tend to have a colour, diameter wider than 2.5µm and/or have uniform septa. Spiral structures are bad, indiciative of anaerobic conditions, and ciliates (hairs all over the body) also indicate anaerobic – bad- conditions. Apart form the spirochete most of these are good.
fungal hypha with septum 400x
fungal hypha 250x
fungal hypha 400x
spirochete – bad sort of bacteria. 250x
I saw only one and this one inactive!
misc protozoa 250x
fungal hypha 400x
fungal hypha 250x
This is on a 5x dilution, the recommended intial conditions (use 1ml of compost and make up to 5ml total with water left to stand so the chlorine has gone).
The easiest and low-tech way of adding the microorganisms from compost is to extract them fro mthe compost using water and a mesh, then spray the water – in our case using watering cans. You can spread the compost itself, and there’s much to be said for that, but it’s more stuff to wrangle and needs to happen before you plant, ideally. Since we are going to test areas on already growing plants, extract it is. Compost tea is a way of getting more microbes out there, but it is technically harder and we don’t have the gear. Extract it is, then. The rate seems to be about a good handful per 5 gallons, we used half an IBC, ie about 500 liters, which is 110 gallons. So we need about 20 times as much
Start with a wodge of compost in a net curtainand 500 litres reasonably clean borehole water (so no worries on chlorine or chloramine)
We made a bag by putting the compost in the middle of the net curtain material and tying up the top with a releasable cable tie.
You can see the brown of the humic acid leaching out of the compost into the waterthe end result is a dark brown chocolate colour
