Digging the bean trench.

The only reason I am triple digging the climbing French bean bed is because I have some brushwood from the hedge alongside my allotment.  I have cut the hedge right back beyond the fence so that more light can get onto the allotment.  There is also a 30ft x Cupressocyparis leylandii  beginning to grow through the fence.  I will be cutting this back as far as I can.

The woody branches are being put on top of some pernicious weeds given to me by one of the top allotments. The weeds were put at the bottom of the trench.  Leaves and turfs are being put atop that.  The subsoil and the top soil are being sieved back into the trench with additions of pigeon and horse manure.

This process produces some really good looking soil.

I decided to take the Takesumi bamboo charcoal to the allotment so that I could marinade it in comfrey liquid.   I am wondering if I can apply this to the ground using the watering can.  It is very fine dust and will easily pass through the rose holes.  It can mash a bit in the tubs for a while until I need to use it.  

Took up six of the Brussel sprouts plants to take home.  Then I gave two to Chris, one to Mike and Mr Singh took some off one or two plants.  Even with all of this I have four plants still left in the ground.  

I think that I may  water the winter cauliflowers, leeks, strawberries, blackcurrants, raspberries, rhubarb and gooseberries with comfrey liquid.  This will give them a good start at the beginning of the season.  

Charcoal is breaking apart in the soil

There is very little evidence of charcoal in the sieved potato soil except for the larger lumps. This is the first area where I used inoculated charcoal.

In the early stages of my experiment I did not crush the charcoal.

I was putting these few large lumps to one side to crush before putting them back on the soil. However, there was little need to use the bull hammer because they seem to crumble easily between finger and thumb. Now I am not sure whether this is due to the soil, the type of charcoal or possibly the natural weathering of charcoal.

I have put quite a lot of charcoal onto this area over the three years that I have been trying this experiment and the charcoal seems to have broken down in to smaller and smaller pieces incorporating itself into the the soil structure.

An aside: What farmers consider as top soil is completely different to what allotment growers would consider top soil.  My top soil has considerably more organic matter and is much darker than this so called farm top soil.  I also had to remove a awful lot of stones - I will take a photograph of the stone that I have taken out.

The soil was particularly poor being replacement for contaminated soil on my allotment. Now, after adding charcoal and carefully cultivating,  this area of the allotment is cropping as well as the rest of the allotment.

 No shops are stocking charcoal this time of the year but you can still get it from the internet.
http://www.creativegardenideas.co.uk/supagrillcharcoal10kg
Just put that in so that I do not loose the web address, which I am always doing.

I have just bought some Takesumi charcoal to see if has any better properties than lump wood charcoal.

I am going to plant some more onions, tomatoes, summer cauliflowers (All the year round) celery and celeriac tomorrow.

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.