Saturday, 31 December 2011

Getting fed up of sieving the potato bed soil.

  I got a bit fed up of sieving the soil today.  I am mixing in some new horse manure and the pigeon muck as well as sieving out the stones.  The ground has become very wet over the last few days and this means that the soil is a little more reluctant to go through the holes in the bread tray sieve.

It is really time consuming and I am wondering whether to give it up for a while and continue to remove the rest of the stones next autumn.

Sieving is good exercise and produces a very friable soil.  The ground is free of cropping vegetables - the beetroot and the carrots are clamped and the parsnips soon will be.  So, I might as well sieve the soil  now and get it over and done with.

The number of stones that are in this soil is remarkable.  It was replacement soil for contaminated soil that was on my allotment and several others. The new soil was supposed to be top quality organic soil.  I am not sure whether it was organic because it was clay, full of stone and empty of both nutrients and body.  When a soil has no obvious organic matter or small creatures you start to wonder if this soil was treated with chemical fertilisers.  These chemicals will kill off things like worms because there is no organic matter in the soil for them to feed on.

This new soil has reacted really well to the addition of copious amounts of  compost, manure and cultivation.  The soil is finally becoming workable.  I am hoping that cultivating the potatoes will help to break it up  and work in the organic matter a little more.

I took the top off a 210 litre blue plastic butt to make a water barrel.  We have had a lot of rain recently and I am missing collecting it.  The down spout was reinstated - it had fallen off in the wind. I am going to duck tape it to the guttering to secure it and then put a small screw through it.  The down spout is tied in securely with wire.

There were quite a few slugs in my beer traps a few days ago.  I emptied them  into the comfrey butt and replaced the beer.  I looked today but there were no new slugs in the beer.   I am happy about the beer traps being effective.

I put some horse muck on the new sweet pea bed and if I have any left over from the potato bed I will use the left overs on the sweet peas.

Sunday, 25 December 2011

Raised beds and no dig.

I'm not dead against raised beds or no dig schemes in the allotment.  I just think that permanent raised beds need high inputs of water, fertiliser and organic matter.  They are also time consuming needing a lot of attention to produce high yields from crowded plants.

Putting large amounts of decomposing organic matter on the surface may deplete the top soil of nitrogen.

Even if  you are  a strict recycler, all these things will be dependant on oil; if only due to transporting them.

Also, I can't be doing with all the paths.  I just look at them and think wasted growing space.

There is some thought that walking on the soil destroys its structure.  I cannot for the life of me go along with this.   In any case plants will grow through concrete - how compacted is that? Plants still grew even with dinosaurs compacting the ground.

Plants need water which they obtain from the soil through their roots.  Roots also obtain dissolved nutrients from the soil and they need energy to do this.  To obtain energy they need to respire using oxygen.  This means that plants need both water and oxygen in the soil.  The more fibrous the structure, the better the relationship between these soil constituents.  Walking on soil will squash out some of the air.  Walking across wet  soil will squash out some of the air and fill the pours with water muddying the soil.

However, needs must and sometimes you just have to work the soil in wet weather.  Going over the ground that you have walked on with a fork restores the structure and allows air to enter the ground.  However, common sense says trying to work muddied ground when it is pouring down with rain is pointless.

I would suggest that the structure of the soil is much more dependant on its organic and mineral content than whether it is walked on.  I read somewhere that if you get the calcium and magnesium content of the soil just right you can park you car on the soil and still have a friable soil.  I would like to try this out before I recommend it though - and that will never happen.

So I will continue to use larger areas, wider spacing, less watering and sharp tools to cultivate the soil and produce good harvests.

Having said all this my beds, which are about 15 foot by 25 foot, are all raised above the original ground level. One of the old blokes on the allotment site said why didn't I use old paving slabs on end to keep the soil from falling on the paths and track ways.  This was a good idea and I have, over the years, put paving slabs around most of the beds.

The ground was raised by the addition of lots of organic matter.  It didn't really matter to me what the organic matter was, it still got buried.  I have buried old cotton shirts, leather handbags and shoes;  leather belts; woollen jumpers and socks; tree and shrub shreddings; shredded paper; weeds except for bind weed and mares tail; tree trunks and branches; lots of tree leaves, muck and manures.  I used to bury woollen carpets too until I found they put nasty chemicals on them to prevent them being eaten by moths and fungi.

All these additions to the soil were buried at least two spits down and mostly further than this.  When I dig down now I find nothing except a darker stained subsoil. The nutrients and carbon locked up in the structure of organic material is slowly returned to the soil to increase its fertility.

Apart from vastly improving the drainage of the allotment and enabling me to use the ground year round, the raised bed is like a hot bed.  The decomposing organic matter generates a certain amount of heat and this can warm the soil enabling seeds to germinate earlier - or that is the theory anyway.

To make the raised hot bed, I don't pile organic matter on the top of the soil.  I bury it deep in the soil.  I do this because I do not want it to deplete the top soil nitrogen.  Putting organic matter on the surface of the soil may deplete the soil of nitrogen when it decomposes.  I know there are many benefits of mulching but it needs to be done with understanding and more care than is often suggested.  Piling on mulches is not a magic solution to all your gardening problems.  It is just one more strategy in the armoury of methods you can use on the allotment.

So my beds are raised but they are much bigger than any other raised beds that I have seen.

There is nothing wrong with raised small beds done well but I can't be doing with them.  They are too small for my way of gardening.

And this time of year I just like to go out and dig for an hour or so.  Allotments are not just for growing; they are for fresh air and exercise too.

Thursday, 22 December 2011

Heritage or modern seed?

I have bought quite a few seeds from the Real Seeds Catalogue but maybe I should have tried a little harder to buy heritage seeds.

However, if you want disease resistant varieties because you need to grow without pesticides then sometimes you need to compromise.  Also, I want to be able to keep some of my vegetables stored over winter and these good keeping varieties are not necessarily heritage.  Cauliflower: Brassica oleracea botrytis 'Clapton F1 Hybrid'  is a club root resistant variety so I thought that I would try it.  It was also half price in an end of season sale so I could not resist it. (Several others of the F1 seeds were in the sale as well so I got them too)  I have been growing Daucus carota 'Flyaway F1 Hybrid' for years to combat carrot root fly.  This year I am growing Resistafly F1 Hybrid.

The bottom line is to produce some organic carrots to eat. To make this a little more certain I will be growing crops that are resistant to pests.

I would like to believe that heritage plants have a greater affinity for mychorrhizal fungi and grow even better with charcoal but I have not found any significant difference between modern varieties and heritage grown with charcoal.  Both types of plants seem to benefit from the application of inoculated charcoal and  mychorrhiza.  Keeping the old varieties going is more to do with biodiversity than anything else.

I have two dust bins full of marinading lump wood, barbecue charcoal.  The liquid is made up of comfrey, nettle, sweet cicely, worm bin and diluted pigeon manure.  It has been marinading for at least five months now and I will not use it until the spring.  I reckon that will be ample time for the charcoal to take up nutrients.

It will be used on the potatoes first.  I cannot get barbecue charcoal at the moment because there is none in the shops, however I still have the Takesumi charcoal to experiment with.

While some of the old vegetable varieties are better flavoured there are many that are not and they are not so disease resistant either.

Looking around the allotment site people are using the same varieties year after year because they grow well in our allotment soil  with our north facing aspect.  These varieties are more or less the same as I am growing some of which are F1 hybrids. I think that I will continue to buy F1 seed at the moment.

Finally, I have got into growing particular varieties and want to carry on if I can.
This is why I kept some seed in 2011 and I am going to sow it during next season (2012). Seed saving has been quite successful this year so I am going to continue to collect my own seed.  For this I need non F1 hybrids because only these will breed true.  Maybe this is an argument for selecting heritage seeds. So, there are good reasons for getting both F1 hybrids and heritage seed and I will be using both.

Monday, 19 December 2011

Seeds for 2012

These are the seeds that I am going to use in the new year.  Sometimes I like to grow specific varieties so I have bought the seeds from various companies.  Not all the seeds have a cultivar or variety.  There are 64 different kinds of vegetable, herb and soft fruit here.  Some are already in the ground while I am getting very impatient about planting some of the others.

Vegetable Latin Name Cultivar
American land cress Barbarea verna
Asparagus Pea Tetragonolobus purpureus ¬¬¬¬¬¬¬¬¬¬
Basil  Ocimum basilicum Dark Opal
Bay tree Laurus nobilis 
Beetroot Beta vulgaris Boltardy
Beetroot Beta vulgaris Wodan F1 Hybrid
Birds foot trefoil  Lotus corniculatus ¬¬¬¬¬¬¬¬¬¬¬ Just a companion plant
Black berry  Rubus fruticosus  Adrienne
Black currant Ribes nigrum Ben Sarek
Black currant Ribes nigrum Ben Lomond
Borlotti beans Phaseolus vulgaris Cuthbert's
Broad bean Vicia faba Own kept seeds
Broccoli Brassica oleracea Early Purple blend
Broccoli Brassica oleracea Sprouting Redhead
Brussel sprouts Brassica oleracea var. gemmifera  Trafalgar 
Cabbage Brassica oleracea capitata Holand Winter White
Cabbage Brassica oleracea capitata Sherwood
Cabbage Brassica oleracea capitata Golden Acre Primo (II)
Calabrese Brassica oleracea Belstar F1 hybrid
Calabrese Brassica oleracea Green Sprouting
Carrot Daucus carota  Early Nants
Carrot Daucus carota  Resistafly 
Carrot  Daucus carota  Nandor F1 Hybrid
Cauliflower Brassica oleracea botrytis Clapton F1 Hybrid
Cauliflower Brassica  oleracea botrytis Winter Alsmeer
Cauliflower Brassica oleracea botrytis All the year round
Celeriac Apium graveolens rapaceum Monarch
Celery  Apium graveolens var dulce Lanthorn Self Blanching
Celery  Apium graveolens var dulce Full White (Self Blanching)
Celery  Apium graveolens var dulce Granada
Chamomile Anthemis nobilis ¬¬¬¬¬¬¬¬
Chicory Cichorium intybus ¬¬¬¬¬¬¬¬¬¬¬
Courgette Cucurbita pepo ovifera Black Beauty
Cucumber Cucumis sativus Wautoma
Cumin Cuminum cyminum ¬¬¬¬¬¬¬¬¬¬
Dill Anethum gaveolens ¬¬¬¬¬¬¬¬¬¬
Florence fennel Foeniculum vulgare Colossal
French beans Phaseolus vulgaris Own kept seeds 
French climbing bean Phaseolus vulgaris Cherokee Trail of Tears
French climbing bean Phaseolus vulgaris Own kept seeds 'Cobra'
Garlic Allium sativum
Goosberry bush Ribes grossularia Xenia
Grape  Vitis vinifera
Hamburg parsley Petroselinum crispum Berliner
Jerusalem Artichoke Heleanthus tuberosus
Kohlrabi Brassica oleracea caulo-rapa Gigant
Lambs lettuce Valerianalla locusta  Cavallo        
Leek  Allium porrium Oarsman F1 Hybrid
Leek  Allium porrum Mammoth Blanched
Leeks Allium porrum Bleu de Solaise 
Leek  Allium porrum Musselburgh
Lettuce  Lactuca sativa Webbs Wonderful
Marjoram Origanum majorana ¬¬¬¬¬¬¬¬¬¬¬
Mizuna Brassica rapa Waido
Oca Oxalis tuberosum ¬¬¬¬¬¬¬¬
Onion Allium cepa Vision
Onion Allium cepa Ailsa Craig
Allium cepa Mammoth Improved
Onion Allium cepa Bedfordshire Champion
Parcel  Apium graveolens var secalinum ¬¬¬¬¬¬¬¬¬¬¬
Parsnip Pastinaca sativa Tender and True
Pea Pisum sativum Early Onward
Pea Pisum sativum Hurst Green Shaft
Pea  Pisum sativum Onward
Potato Solanum tuberosum Kestrel
Pumpkin Cucurbita pepo  Rouge Vif dEtamps
Radish  Raphanus sativus Cherrybelle
Raspberry Rubus idaeus
Rhubarb  Rheum rhaponticum Champaign 
Rhubarb  Rheum rhaponticum Timperley Early
Rocket Eruca sativa Sweet Oakleaf
Runner beanPhaseolus coccinus Own kept seeds
Sage Salvia officinalis Green Leaved
Salad Burnet Sanguisorba minor ¬¬¬¬¬¬¬¬¬¬¬¬¬
Salsify Tragopogon porrifolius ¬¬¬¬¬¬¬¬¬¬¬¬¬
Scorzonera Scorzonera hispanica Maxima
Shallots Allium ascalonicum Jermore
Spinach Spinacia oleracea Mediana
Spinach Spinacia oleracea Renegade F1 Hybrid
Squash Cucurbita moschata Waltham butternut
Strawberries Fragaria ananassa  Cambridge
Swede Brassica napus napobrassica  Gowrie
Sweet cicely Osmorhiza claytonii ¬¬¬¬¬¬¬¬¬¬¬¬
Sweet corn Zea mays Double Standard
Sweet corn Zea mays Northern Extra Sweet
Sweet pea Lathyrus odoratus Many
Swiss Chard Beta vulgaris subsp. Cicla Galaxy 
Tarragon  Artemisia dracunculoides ¬¬¬¬¬¬¬¬¬¬¬¬¬¬
Tomato Lycopersicon esculentum. Rose de Berne
Tomato Lycopersicon esculentum. Dr Carolyn Pink
Tomato Lycopersicon esculentum. Latah (Bush)
Turnip Brassica  rapa Oasis
Turnip Brassica  rapa Galaxy F1

The allotment plan does not allow for all of these seeds and I will probably be keeping some of them for next year or for later planting.

Vegetables that I have never grown before are Tarragon, Salad Burnet, Dill, Cumin, Asparagus Pea and Parcel.  Now I think that parcel is a bit of a con because it is  celeriac under a different name.  It says  that you eat the petioles and leaves rather than the swollen stem.  Oh well, I'll give it a try.

Getting these latin names right is a pain.  Brussel sprouts in Johnson and Smith's "Plant names simplified" are called Brassica oleracea bullata, while elsewhere they are referred to as Brassica oleracea var. gemmifera.  Now, I would go with bullata because that means bubbles or blisters and is a good description of the buds.  However gemmifera means a similar thing - a plant with stem buds.  The RHS who seem to be the authority on these kinds of names calls Brussel sprouts Brassica oleracea gemmifera so that is what I will do.  I have had the same difficulty with the swede.  It is a type of Brassica napus that colours the fields with yellow in the summer.

I haven't grown celery for a very long time.  It is very demanding of both nutrients and water.  I am going to grow it at the bottom of a trench to see if I can keep it damp enough.  It is also very susceptible to slug damage so I am trying to reduce the slug and snail population now.  This means that there will not be so many next year to reproduce and create a problem.  At the moment I am using beer traps and Ferric phosphate but next year I plan to use a lot more nematodes Phasmarhabditis hermaphorodita to help to keep the slug and snail population down.  

I think that I will have a lovely variety of vegetables next year.  Now all I want is to find some really great recipes for cooking them.

Sunday, 18 December 2011

Keeping sweet pea seeds

This year I have kept a lot of sweet pea seeds and planted them in pots at the end of October.  They have all germinated well. My assumption was that they would not breed true because of cross pollination between varieties that were grown quite close to each other.

However, it seems that  sweet peas are normally self pollinated.  While this may suggest that all sweet pea seeds will breed true, there is some doubt whether this is always the case.  My sweet pea plants were not protected from cross pollination - they were "open pollinated".

Now I had always thought that a bumble bee landing on the keel petals of the flower would make the stamen pop out and coat the underside of the bee with pollen which would then be taken to the next flower.  The fact that the stamen and stigma are protected by the keel petals seems to give the flower more chance of self pollination.  When the flower has gone over, pollen has been shed and fallen on the stigma which does not normally protrude from the petals giving a self pollinated flower.

If the sweet pea is self pollinated then it should be quite easy to keep varieties pure because they would only change by mutation. This might give the opportunity for saving seed with some reliability that doing so would produce the same variety as the parents.
Sweet Pea Stamens
Stamens and stigma of sweet pea Lathyrus odoratus (FCIT)
I'm not so sure and will carefully examine  flowers next year to see if this is true.  Unfortunately, I mixed up all the seeds that I gathered this year so I will get a mixture of colours when I plant them out next year.  

Saturday, 10 December 2011

Planning for (Napomyza) Phytomyza gymnostoma

This is the leek and onion miner fly, which I am battling with on the allotment.  According to the Central Science Laboratory the first record of Phytomyza gymnostoma  in England was in 2003 when the fly was formally identified on allotments around Wolverhampton.  I reckon that it was on my allotment in 1999 at least.  I had decided to give up half of my allotment in 1998 and then used the top bed on the allotment to grow onions.  I remember someone saying my onions look a little worse for wear. The onions were slowly twisting up.

As I am an organic gardener and there is no effective chemical method of combating this little fly anyway, the  way to protect the onions Allium cepa; the leeks Allium porrium and the garlic Allium sativum from Phytomyza gymnostoma is to cover them with a barrier. 

The adult flies are about 3mm long so the mesh of the barrier needs to be finer than this.  There can be no gaps in the barrier and the best way to construct it is with hoops covered with enviromesh netting.

I am using 2.5 metre lengths of 20mm water tubing with a bamboo cane secured along the top to give more stability.  The blue piping is just stuck into the ground.  The enviromesh is stretched over the top of the hoops and the edges are buried in the ground.

This will give a large protected area for the onions and leeks.

The dates that I am going to cover the onions and leeks are March 15th 2012 till May 20th. 2012.   This should cover the time that the adults are flying.  They are probably flying for less time than this but it will ensure that the Alliums are covered for the correct period.  The nets will go back on the leeks on the 1st. of  September 2011 and come off on the 1st of November 2011 when the adults are no longer flying.

There is some evidence that the Larvae, which is 6mm long, can travel through the soil when the Allium plant it is infecting rots away.  Hopefully, burying the enviromesh edges will prevent the Phytomyza gymnostoma larvae from reaching the protected area.

Regardless of how weedy the onions, leeks and garlic get during this period, I will not remove the mesh until the dates listed.  I have seen some people's onions when they have removed the mesh for weeding and it is obvious that the fly has reached the plants.  I will be watering through the mesh.

That's how I am going to deal with Phytomyza gymnostoma.   

Friday, 9 December 2011

Using pigeon manure

I am trying to remove all the large stones from the new potato bed which is quite a chore.  Both the top soil and the subsoil need to be sieved and this is time consuming.  The sieve I am using is the bread tray.  While I am sieving, I am adding pigeon manure; compost; horse manure and sieved turf to the top soil.  

The bread tray sieve
The pigeon manure has a  ratio of 4/2/1 which is fairly good going in the realms of manuring NPK ratios.  Chicken Manure (fresh)   has a NPK ratio of 1.6/1.5/1.0 so pigeon muck compares very well with this.  Now I don't really think that I should give an awful lot of credence to these ratios because I got them from the internet and you should never believe anything you see on the internet.  Having said that,  it does give you a rule of thumb. 

It is obvious from the ammonia smell coming off the pigeon muck that it is very high in nitrogen. And loads of people tell you how good chicken manure is and I agree with them.   So if pigeon muck is like chicken manure,  it will be a valuable addition to the soil.  However, the high levels of nitrogen can damage roots and foliage unless  pigeon muck is added with care.  This is why I am adding the manure now, when there are no plants growing in this soil, so that it can rot down a little more during the winter.  By the time I plant potatoes the concentration of nitrogen should be at a level that will not cause damage. The damage that it causes roots is due to the high concentration of salts in the rhizosphere that cause water to be drawn out of roots desiccating them.  This is what people call burning the roots.     

The various additions to the soil have been really well mixed because of the sieving.  It has also produced a very friable soil.  There is now a good mixture of manure, top soil and compost fairly evenly mixed throughout the soil profile to a depth of about 600mm.  Homogeneity of the soil mixture means that there are no high concentrations of manure in some places while other parts of the soil profile have little or none.  There seems to be more benefit in producing a homogeneous soil, where all plants have equal access to added nutrients and organic matter, than having a patchwork of high and low concentrations of nutrient.  Manure added in the top 300mm of soil is most readily taken up by plant roots so this is where the manure should be mixed in.  However, I am trying to encourage mychorrhizal symbiosis and the fungi will be able to access nutrients below the 300mm depth and be able to transport them to plant roots.

I would have dug deeper but I was digging up the x Cupressocyparis leylandii shreddings that I put in last year as a kind of Hugelkultur.  The whole idea of using shreddings is to provide a sponge for water which will be released slowly throughout the summer.  I didn't really want to damage my sponge by mixing it with topsoil.  

I don't know whether it works but it keeps me happy doing stuff like this.   

I dug right up to the Boltardy Beta vulgaris  so I cannot carry on digging until the beetroot, carrots and parsnips are taken out.  

So to begin the clearance, I harvested Beta vulgaris;  Petroselinum crispum; Tragopogon porrifolius; Scorzonera hispanica;  Daucus carota;  Pastinaca sativa and Oxalis tuberosa.  However, I still have a lot left in the ground.  Who says there is nothing to harvest during the winter? I did not harvest any Allium porrum or Brassica oleracea bullata   mainly because they will stand for a while without deteriorating.  I was also going to get some Eruca sativa but it got too late and dark.  I will have to get some tomorrow.  

Still eating the pumpkin Cucurbita pepo and the Apium graveolens rapaceum  that I harvested earlier in the week.  

I am going to put some of the root vegetables into a box in the shed and cover them with soil.  The rest will be clamped and really I need to get onto doing that quite quickly because we are having the second heavy frost tonight.  

How I make a clamp.
The best way to make a clamp is to put a layer of gravel onto the soil; put the carrots on top with a little top soil to keep them in place;  cover with straw and then cover the straw with top soil.  This keeps them in fairly good nick for most of the winter.  I will probably use them all before the end of the winter though.  I used this method for the parsnips too.  

I am going to try to grow some long carrots next year so I took the bread tray sieve up to the new roots bed and began sieving the top soil.  I want to remove all the stone so that the carrots do not fork.  No fertiliser is being added at all because this may also make the carrot roots fork.  I'm not sure whether this is true but I am not taking any chances.  Really, the soil is in good heart and I don't think that it needs fertiliser.  The carrots are going where the squashes were last year and I added a lot of compost for the squashes.  This should be more than sufficient for the Daucus carota.  

Water from the springs has started to flow down the side of the allotment again so I am going to dig out a new soak away and put in another drainage pipe alongside the allotment.  I am going to put the soak away under the tap path and this will involve lifting two slabs.  Not something that I am looking forward to.  I have not raised these two slabs since I put them down in the 1980s.  It means that there is still some top soil underneath them.  I will use the bread tray to sieve this top soil and put it on the allotment somewhere.  The hole will be filled with stone that I have sieved from the potato bed.

This is a central precept of permaculture:  Always turn an adversity into something positive.  So the stones will be used to make the soak away and the slabs will be put on top.  This means that I will gain some more topsoil and a soakaway. There is no downside.  Second thoughts; it's cold and wet and it was trying to snow today.  That's the downside.
There are some leaves mixed with lawn mowings in the bins by the gate but I have not used any of them yet. 

Friday, 2 December 2011

Takasumi Charcoal

The Takasumi charcoal has arrived in a big box.  I am still thinking about how to use it.

I will be marinading some of it in comfrey liquid but I am thinking of trying some of it neat.  I reckon that it would be more effective if inoculated with nutrients, however I might be wrong.

Lots of the experiments that the commercial firms have done are using pot plants.  What might be illuminating is how it affects containerised tomatoes in the greenhouse.  The conditions there might be a little more homogeneous than outside and the growing medium used could be from the same batch.

This I will do.

Thursday, 1 December 2011

More interest in Biochar and Terra Preta?

It is surprising that the "Allotment and Leisure Gardener" (the NSALG magazine) has an article about biochar in it.  I knew that the Japanese have been using biochar for hundreds of years and that they thought that it had a beneficial effect on plant growth but it does not seem to have been accepted by mainstream gardening until quite recently.

I have been experimenting with inoculated, lump, barbecue charcoal  (i.e. marinaded in comfrey Symphytum x uplandicum; nettle Urtica dioica; sweet cicely Myrrhis odorata and worm bin liquid manure mix.) mixing  mychorrhizal fungi to the dried crushed inoculated charcoal before adding to planting holes and seed drills.
Charcoal marinading in the rich black comfrey liquid mix
Sweet cicely being added to the comfrey bins. It will rot down to
a rich black liquid manure which can be tapped off.
Nettles and comfrey are also added to the bins to rot down
and give a rich black humus rich liquid.

I have convinced myself that this is an effective soil amendment and that plants seem to respond remarkably well to the charcoal especially if growing on poorish soil.

As  German and American research has indicated, the biochar black earths or Terra preta of the Amazonian rain forests are incredibly fertile allowing crops to be grown for millennia while elsewhere in the rainforests crops soon deplete the soil of nutrients.

Experiments with biochar amendments to soil by modern scientists have not shown remarkable differences in the growth of plants because it needs to be inoculated with nutrients.  It does not seem that the Takesumi bamboo charcoal is inoculated with anything.  Whether the "Takesumi"  bamboo biochar is more effective than lump barbecue charcoal remains to be seen.  I would rather use charcoal that has been inoculated and used in conjunction with mychorrhizal fungi because this is what I have found to be effective.  "Carbon Gold" seems to have the same kinds of ingredients that I have been experimenting with so I would expect this to have more of an effect than the "Takesumi".

There is an offer in the NSALG magazine so I will look at the site and see if it is worth getting some and experimenting with it.

Well, as it is 70% off and it is worth having a go with, I am going to get some to see if it is more effective than using the lump charcoal.

There is thought that there may be differences in properties between woods that are used; the temperature it is charred at and the fineness or coarseness of the final crushed charcoal.  Indeed there may be a difference in the properties caused by the materials charred.  Any organic matter can be used to make biochar.  Crop waste such as the stems of sweet corn Zea mays is being used in the USA.  So finding the most efficacious biochar is an ongoing challenge.

My very limited experiments have to be restricted by the time I can devote and the amount of money that I can throw at it.  That is why I am using barbecue charcoal and crushing it with a bull hammer after inoculation.

It may not be the most effective biochar to add to the soil but it works for me.

Thursday, 24 November 2011

Finished digging the new potato bed

I haven't really finished digging because I haven't dug the area where the roots are.  I will dig this new area quite deeply like I did on the other half of the bed and remove all the stone using the bread tray sieve.  I think that I have done this fairly well in the area I have dug already.

I have removed considerable amounts of stone.  This has been replaced by topsoil, horse manure and pigeon manure.  All the soil and manures went through the makeshift bread tray sieve because it helps to mix them together.

The new topsoil has come from turfs left in the bins by the allotment gate.  I sieved out the topsoil using the bread tray sieve.  The grass was put at the bottom of the double digging trenches.

One of the advantages of digging is that it mixes well and manures get distributed throughout the soil profile.

If you look at the horticultural textbooks, it tells you that some nutrients come from the weathering of rocks.  I considered this carefully.  Stones come from rock.  I am removing lots of stones from this soil.  Maybe if I weather these stones by hitting them with the bull hammer and return the dust to the soil, this would add nutrients to the soil.

There may be few nutrients in quartz and sandstone but I still give them a tap with the bull hammer.  Plants do not need a great deal of micro nutrient from the soil so the little that I get from stone might be sufficient.

As I was sieving out the stone from the soil, I also sieved out large pieces of inoculated charcoal that I had used in planting holes.  I don't think that the larger pieces of charcoal are doing very good jobs so I am hitting them with a bull hammer to crush these too.  It is all getting mixed into the topsoil through the sieve.

When using a no dig system of gardening, nutrients are put on the top of the soil in the form of compost and worms are used to distribute this throughout the soil profile.

Although digging seems to kill a few worms, there are still a great many worms to do a similar job when the soil is dug.  Also there is nothing stopping me from putting a layer of compost or manure over the dug bed.  In other words you can go up adding compost to the soil surface or you can go down adding compost or manure to the subsoil.  Or you can do both.  I would rather do both.

Digging might destroy mychorrhizal symbiotic associations and this is one of the few disadvantages to digging. However, this will occur when crop plants are harvested anyway and new associations can be promoted using  commercial mychorrhiza spores.  The subsoil in this bed was so hard that I could not get a spade into it.  I had to use a fork.  Although there were a few resourceful worms that had worked their way into it there was little evidence that many other organisms were making it their home.  When I was sieving this subsoil I was mixing in topsoil from the turfs, horse manure and pigeon manure and this gave it a very friable texture.  Introducing carbon (organic matter) throughout the soil profile should mean that there is a source of food for a wide range of soil organism.  This should increase the soil micro organism population and diversity.

There are times when there is no need to dig so I don't dig.  However, passing the soil through the makeshift sieve has produced a really fine tilth and this makes all gardening jobs much easier.  I will have to earth up the potatoes next spring and summer and having this really fine tilth soil will make it much easier.

I raked over the soil after finishing digging and it was a delight because it was so easy.

Put some xCupressocyparis leylandii shreddings on the pathway between 25(b) and 26(a) and I am going to plant a little hedge of Lonicera nitida, which is a honeysuckle would you believe, along the path.  Lonicera nitida doesn't have a honeysuckle sent though.

Sunday, 20 November 2011

Growing medium, compost or just plain soil?

I had an interesting conversation at the weekend, which I am still mulling over.

Most of the commercial seed and potting 'composts' sold nowadays do not have compost in them.  Most of them are peat mixes with such things as perlite, vermiculite, sand and wetting agents like celcote.

Not much compost in them.  So should they be called composts?  I don't think so.

These are growing mediums.    They are sterile, open and water retaining so what is the problem.  Although we might be focusing on growing and gardening, it does not negate consideration of our actions wider implications.  One consideration is the destruction of  peatland habitat by peat extraction.  Maybe it is better to avoid using peat if possible.

Garden composts use sustainable materials and need less transport than growing media.  It is also more fun to make  your  own compost as  we did in the olden days.

I have a very large growing area and covering this with bought growing media is just not viable.  The cost would be astronomical.  Using the two compost bins, I can generate quite a lot of compost and dig it into several of the  beds.  I supplement this with liquid comfrey; a little chicken manure; leaves; blood fish and bone and the free horse manure that is delivered to the allotments.

This has produced some fairly good vegetables for over thirty years now. 
Emptied compost heaps 

Compost heaps filled again

Compost heap growing potatoes and pumpkins.  

Compost nearly ready to go onto the allotment.

This compost  is ready to be used.

Sieved compost being added to the top soil.

I used to make seed and potting composts at the Glasshouse Crops Research Institute.  This was before they developed their peat based growing mediums.

In the olden days soil or old turf was sterilised in large steam boxes. And they were big boxes.  My first job in the glasshouses was to fill and empty the boxes.  The soil was emptied sieved and heaped into a conical pile on the floor of a large barn after sterilisation.  It being the olden days and not knowing any better, peat and inorganic fertilisers were added and mixed  in by shovelling soil from the bottom of the pile to the top. And they were big piles.

When we had done this about ten times the soil was passed through a shredder which threw the soil into a concrete bay.  

Not too sure whether this was compost either.

I grew some really good tomatoes using just the sieved compost from Fred's Mega Compost:

Maybe this is the way to go?  However, I need a steam sterilizer.

Having always gardened using the original soil, I find it very difficult to accept that developing a vegetable garden with growing medium is the right way to go.  I want to garden with the least cost both  financially and environmentally.  I don't want to spend lots of money on something that I can produce for nothing.  Covering my allotment with commercial growing media  is just not a feasible option; it is just too big.

There are another three beds beyond the sweet pea canes
Although there are many types of different growing media and composts, it seems ridiculous to ignore the most valuable resource which an allotment or garden has to offer.   A good well made soil.  

 Good soil  with lots of  well rotted organic matter

Soil planted with green manure.  

Undoubtedly, soil preparation and improvement is a major part of success in the vegetable garden. It takes nature about 1000 years to produce 20 mm of soil .  However, adding dead organic matter to the soil and artificially weathering it by digging or rotavating, we can of course increase the amount of top soil available for cultivation quite considerably.

Anthropogenic soil improvement by adding amendments will change the soil relatively quickly, although my soil is only just becoming beautifully friable and highly productive after thirty years of adding organic matter.  I would never suggest that pedogenesis is an easy or quick process that can happen overnight but there are things that gardeners can do to improve the soil for cultivation of vegetables and flowers.

It is difficult to think in three dimensions when considering the environments in which plants live.  The environment of the root is very different to that of the plant's aerial organs.  It is easy to observe the parts of the plant that are above the surface of the soil but underground organs are more of a mystery.  This environment can be studied and analysed for its structure, texture and nutrient content but this does not begin to picture the whole amazing dynamic that is called the soil. 
The soil is an amazing environment that is inhabited by vast numbers of organisms.  In order to survive they must interact with each other competing and cooperating in a dance that allows reproduction to be ensured and the continuation of the species. 
While foraging for water and nutrients, the roots of plants must find methods of protecting themselves from pathogens whilst interacting with symbiotic and helpful organisms.  Although the majority of the soil has a sparse population of microorganisms, there is much activity around the roots of plants and wherever dead organic matter can be found.  Thus a homologous soil with organic matter evenly distributed throughout its three dimensional space will be one with the most active organic life and the best environment for plant roots. 
The natural soil profile is one of layers; an organic layer, a top soil layer, a subsoil layer and the bedrock from which the soil is formed.  It relies on soil organisms to mix the constituents and this is probably why it takes over 1000 years to produce 20 mm of good fertile soil.   However , this is not the totality of types of soil profile and where soil has been mixed as in river silt or settled from dust filled air from a volcano the fertility and organic content can be fairly high throughout the profile. Digging and other forms of cultivation just speed things up a little.  There is no virtue in layering the soil and waiting for nature to mix it for you.  It will take 1000 years...

The modern fashion for using raised beds to grow vegetables can be seen as a method of avoiding digging.  The no dig system seems to have been developed, like so many other gardening techniques by trial and error.  Afterwards  the amateurs that developed it become evangelical and the gullible see it as some magical method;  following the method’s recipes and instructions as if there were no other ways of cultivating the ground in a sensible way.  It’s just multiple layers of this and that built up within planked containers to make higher than ground level growing areas.  And lots and lots of paths.  
The raised bed method developed from la culture Maraîchère; the French intensive hot bed method which used horse manure decomposition to create heat and allow crops to be grown throughout the year on raised beds.   Frames and cloches were used to entrap the heat and enable vegetables to be grown even in very cold weather.  The Victorian gardeners copied this but also started to use tan as an alternative. 
I do not think that there is anything magical in the materials that are used to develop these raised beds.  Indeed, filling a raised bed with commercial multipurpose growing media or ordinary garden soil seems to get good results.  Mainly because both materials are either well sieved and mixed or become well mixed during the raised bed construction.    Adding imported sterile commercial growing media that has been mixed and sieved is just the same as digging over your garden but without the effort and with lots of costs both financially and environmentally.  Also this material is neither compost nor soil. The sterility of the growing medium prevents the recycling of nutrients because there are no bacteria, fungi or invertebrate life.  Without this living fraction of the soil, fertility cannot be maintained because there is little to prevent the leaching of nutrients and there is no turning up of nutrients from lower in the soil profile. 

Without intervention, organic matter will accumulate on surface of soil.  Worms incorporate this into the soil’s first few layers. However, they do this relatively slowly so those that do not dig their vegetable plots may experience a lowering of fertility over the years even though they have added organic matter to the surface of the soil.  

Adding organic matter, where nutrients are locked into molecules that can be broken down by saprophytes, produces a long term sustainable process of soil fertility improvement.  It is a slow acting decomposition which does not saturate the soil with leachable nutrient.  What goes in the soil stays in the soil unless it is taken up by plants.

Most gardeners import animal manures, shredded woody material, lawn mowings and leaves to their growing areas.  Although this is a necessity, the environmental and financial cost of these amendments is one of the considerations that has to be taken into account when developing a growing area. 

There are some methods where you start with a layer of news paper to suppress weeds and then cover with compost or other organic material such as straw or hay in layers with some addition of animal manure.  The layers are built up until the correct height is obtained and a surface layer of compost or soil tops it off.  Certainly it is a very intensive organic matter form of gardening. 
However, there seems to be little mixing of layers.  This will give relatively high concentrations of nutrients in some parts of the profile, while others have little.  Such efforts to separate the raised bed from the native soil seem perverse.  To produce a viable soil with this method, particularly if it is no dig,  would need worms  to  mix the various layers of the lasagna.   Most raised bed systems start with thick impenetrable layers of weed suppressant material.  Only the most persistent worms would get through that. 
It is a quick and relatively easy way of cultivating an area of weed infested ground because weeds are suppressed by the newspaper in the raised bed and paths are covered with weed suppressing membrane.  However, choose your weeds well because if you have Calystegia sepium or Equisetum arvense, you will not get rid of them this way.  It is always difficult to eradicate these weed, but digging them out does help to reduce their persistence. 
A good garden soil would be one that is homogeneous.  The fertility and organic content should be evenly distributed throughout the profile where it will be equally available to plant roots wherever they are.  This will prevent the roots from bunching around the improved soil in the planting hole and not venturing out into the surrounding soil. 
Sterile commercial growing media (composts) work so well because nutrients, air and moisture are evenly distributed through the sieved and carefully mixed compost.  They are engineered to produce the best results or they would not be able to sell them.
Permanent raised beds need high inputs of water, fertiliser and organic matter to maintain their fertility, just like ordinary garden soil.  The manufacture and transporting of both the raw materials and the final compost product will be dependent on oil.  Also, having to raise everything up to the raised areas makes them time consuming; needing a lot of attention to produce good yields from crowded plants. 

Fungi send out a gossamer candy floss of delicate hyphae that touch all the life in the soil recycling nutrients in an intimate intertwined association that involves most plants.  These are the mychorrhizal fungi. 
Bacteria also form symbiotic associations with the roots of plants allowing nitrogen fixed from the air to be passed to the plants.  Other bacteria fix atmospheric nitrogen and only pass it to the soil when they die or are consumed by some other part of the soil fauna and flora. Should these vital components of soil be disturbed by digging.  

There is some debate that says that the soil is rarely disturbed in nature and has not evolved to cope with being cultivated to the extent it is on allotment gardens. 
I would rather work with native soil which is not sterile and contains high levels of soil organisms such as nitrogen fixing bacteria and mychorrhizal fungi.  Digging is supposed to damage these organisms but they are microscopic and great effort would be needed to damage such small structures. 
Digging does damage some of the larger organisms – particularly the worms and this does need to be taken into account.  However if homemade  compost  is being used to  increase the organic content of the soil then a large population of soil organisms are introduced particularly if it is used as a mulch on top of the dug earth. 

Some commentators say that digging will bring dormant seeds to the surface of the soil; their dormancy will be broken and germination will ensue.  I have dug and not dug and regardless have about the same amount of weeds whatever  I do.  The survival strategy of ephemeral plants is to quickly colonise bare ground by various dispersal mechanisms.  Senecio  vulgaris and Taraxacum officinalis  both have very effective clypsela which are wind blown particularly onto my allotment and I am having to clear them  off continuously.

You are going to have to weed regardless of any strategy that you adopt;  you just have to get over it. Gardening is hard work - but very rewarding.

Mulches and green manures enable the beds to reach high levels of fertility and this can be maintained over many years.  Leaching is reduced and chelating humin, fulvic and humic acids will form complexes  that will entrap minerals in the soil structure.  

Going up or going down does not matter.  Deepening and increasing the fertility of the layer of top soil can be achieved by both.  I have raised my whole allotment about 600 mm above the original ground level and this does seem to improve the drainage.  However I have dug down quite deeply too and broken up the subsoil to quite a depth, adding organic matter, and this might be the main factor in improving the drainage.  Large amounts of organic matter in the form of logs, branches, woody shreddings and leaves have been added to the subsoil in a kind of trench Hugelkulture which might also improve the drainage of the allotment soil. 
Cupressocyparis laylandii shreddings

Mostly Acer pseudoplatinus leaves
Quercus  robur brushwood

Quercus robur branches

Good old farmyard manure.
In my experience adding large amounts of organic matter does seem to improve the fertility of the soil.  It could be conjectured that this is part due to the provision of carbon for free living nitrogen fixing bacteria such as Azotobacteraceae.    These bacteria are fairly ubiquitous and once they have a carbon source will multiply rapidly whether the organic matter is on the surface or mixed into the top soil.  It is hard to believe that digging would severely deplete the numbers of bacteria in the soil especially if it is combined with adding organic matter.  Hugelkulture, where logs, branches and brushwood are used to make raised beds should really be buried away from the top 300 mm.  of the soil profile.  Trenching and bastard digging allow very high carbon content material to be added to the soil with some success. 
Deep trenches will dispose of large amounts of unwanted organic material.  It can  also be a repository for more pernicious weeds.  While Elymus repens and Urtica dioica can be buried, mare’s tail Equisetum arvense and bind weed Calystegia sepium must be put into the worm bin because they will survive burial even at this depth. 
Logs, branches, brushwood and shredded woody material rots down to a very friable compost after two or three years and this can be incorporated into the tops soil.  While it is rotting down it is forming a sponge like layer that allows water to pass through for drainage; keeping some water as a reservoir for drier periods. 
Tanner’s bark was used in hot beds during Victorian times because it warmed up just like fresh farmyard manure. It  was used in tanning leather.  Mostly oak bark was soaked in hot water to remove tannin and afterwards discarded or given to gardeners.   This woody material was preferred to manure because it kept its heat for up to six months.  Putting shredded woody material under the soil may well have a warming effect too. 
The alternative to burying high carbon material could be to shred it and put on top of the soil as mulch.  It will help to retain top soil moisture and suppress weed seed germination.   However, mulches do attract slugs and snails and may be of more use on mature plants that are not so attractive to these voracious molluscs.  I do not use mulches on vegetable beds until the plants are very mature.  Hoeing is just as good when the plants are immature.  Putting large amounts of decomposing organic matter on the surface of the soil may deplete the nitrogen content of a couple of centimeters of top soil.   

Remember adding carbon reduces nitrogen; adding nitrogen reduces carbon and adding air reduces both.  

Having large reservoirs of carbon deep in the soil may increase the population of beneficial carbon eating microbes like mychorrhizal fungi.  Symbiotic connections could link plants to the decomposing plant material deep in the soil through fungi mycelium.   In order to protect these fungi and other essential microorganisms inoculated charcoal could be added to provide both a protective habitat and  a source of nutrients.   This is what the native South Americans did for thousands of years.  It is the soil called terra preta. 

It is understandable that the repeated addition of inorganic fertilisers would reduce the number of soil organisms by reducing the amount of carbon available to the heterotrophic soil fauna.  However, there are few gardeners that will use inorganic fertilisers to the extent they were used in the past. 
The adding of dead organic matter to the soil also has a number of other benefits that add to the fertility of the soil.  Plants respire as well as photosynthesise.  This means that they take in oxygen as well as carbon dioxide.  As the roots are below the soil they do not have access to light and cannot photosynthesise.  Yet they do respire and need a supply of oxygen from the soil.  Dead organic matter can increase the amount of oxygen that can penetrate the soil by providing air spaces and keeping the soil "open".  In a similar way organic matter can provide a route through the soil for water increasing drainage to avoid water-logging.  As organic matter absorbs water it also provides a reservoir that buffers water-logging and drought. Organic matter and clay are the hooks that enable nutrients to remain in the soil and available to plant roots and mychorrhizal hyphae.  In order to get the maximum benefit from the organic matter added to the soil it should be distributed evenly throughout the profile by digging. 

Mychorrhizal saprophytic fungi form symbiotic associations with plant roots which allows nutrients that are produced by fungal breakdown of dead organic matter to be transported to the plant.  There is some suggestion that these networks of fungal hyphae connect plants with each  other allowing the flow of nutrients and photosynthesis products to move to plants that are compromised because they are in shady or nutrient poor environments.  

I would suggest that my soil is more productive now than it was when I took the allotment on over thirty years ago. A lot of nutrients have been taken off the allotment in the form of vegetables, eaten and disposed of down the sewage system. The reason why it is even more fertile now is due to the addition by digging of dead organic matter in its many forms.  It would never have occurred to me to use growing medium to improve my top soil when I started gardening. Indeed I would have avoided peat because I saw it as an acid medium.    A good load of cow muck was about all that was needed.  I doubt if I could have increased the fertility as much by adding peat based growing mediums even though they are infused with inorganic fertilisers.

You can use any organic matter to produce good soil.  The word organic, in this context, means that which was once alive. (In chemistry it refers to any molecule containing carbon chains.)  There are many lists circulating around the gardening forums.  Regardless of their NPK ratio accuracy, they give a list of things that you can add to the soil or compost heap  that will decompose to give plants nutrients.

Adding any dead organic matter to soil will benefit it.  There is evidence that ancient human settlements can be identified by high phosphate and charcoal levels in the soil.  This leads to a lush growth of plants that has been maintained over many centuries.  I doubt if ancient human civilisations were as selective of the organic matter they buried as modern man is. The self sustaining properties of Terra Preta soils are probably due to an indiscriminate addition of dead organic matter together with charcoal.

Seaweed contains a lot of nutrients - particularly potassium and is a valuable amendment to soil.   So much of our nutrients are sent down the sewers and eventually into the sea. Using seaweed seems to close the cycle so that these nutrients can be returned to the soil.  

There is a suggestion that adding undecomposed organic material could be detrimental to the soil.  This is because micro organisms need nitrogen and forage for this in the soil when they are decomposing organic matter.  Well what goes around comes around.  These organisms will die themselves and decompose in the soil and provide nutrients.  If you are continually adding organic matter into your soil,  then the cycle of decomposition and growth develops a dynamic equilibrium where the level of nutrient in the soil matches the amount being used by living things preventing leaching and locking the nutrients into a sustainable cycle.

If the soil is very compacted then it will need to be double dug to improve the drainage and begin to increase the depth of the top soil. 
Raised beds mean that you don’t have to step onto the bed to cultivate it having access from the many paths around the beds.  The soil is never compacted and is always aerated and well drained. 
Plants need water which they obtain from the soil through their roots.  Roots also obtain dissolved nutrients from the soil and they need energy to do this.  To obtain energy they need to respire using oxygen from the air.  In other words plants need both air and water in the soil.  The more fibrous the structure of the soil the better the relationship between these soil constituents.  Walking on the soil will squash out some of the air.  Walking across wet soil will squash out some of the air and fill the pores with water muddying the soil. 

However, needs must and sometimes you just have to work the soil in wet weather.  Going over the ground that you have walked on with a fork restores the structure and allows air to reenter the ground.  Having said this, common sense says trying to work muddied ground when it is pouring with rain is pointless.  

Soil compaction by the rain is more of a problem in the vegetable garden although taking a hoe through the surface will usually be good enough to allow air to enter the soil. 

When making seed beds you should consolidate the soil by shuffle walking over it to break down the clods of soil and produce a fine tilth.  

The soil can also be compacted by animals like rats, badgers, foxes and the like.  Let’s be honest here, dinosaurs trampled the earth in the past and soils survived.  

The structure of the soil is much more dependent on its organic and mineral content than whether it is walked on.  I have read somewhere that if you get the calcium and magnesium content of the soil just right you can park your car on the soil and it will still be friable.  I would like to try this out before I recommend it – and that will never happen. 

Seedbeds need to be consolidated to conserve water and to ensure good seed soil contact for optimum germination.  This is why you sometimes see farmers using Cambridge rollers to consolidate their land.   I was always taught to shuffle over the soil to consolidate it and then rake it carefully to make a good seed bed.   It would take a very large weight or constant use to squeeze out all the air from soil.  Keeping your soil too fluffy just leads to problems with irrigation.   In any case, plants will grow through concrete – how compacted is that?