Sunday, 19 August 2012

Planting the green manure

Rather than creating my own green manure seed mixture, I have bought some grazing rye and winter tares seed already mixed.

The grazing rye forms an incredible fibrous root system that holds moisture and nutrients within the top soil.  It forms a dense mass of leaves that cover the surface of the soil an protect it from winter rain.  Both the roots and the leaves are a reservoir of  nutrients that will break down quickly when dug into the topsoil during the spring.

Tares and rye green manure 
The winter tares are in the leguminosae family which form symbiotic relationships with nitrogen fixing bacteria.  Nodules of bacteria form on the roots and provide the plant with nitrogen which is incorporated into proteins within the tares's cells.  (NB the apostrophe is in the correct place)

Green manure planted in rows goes further
and forms a weed suppressing canopy

All the green manure has been planted in rows.  It gives
the opportunity to hoe out weeds when the green manure is
small like this.

It grows best if sown in the late summer
- late August or September in the UK

This green manure has grown well but
later sowings have been attacked by
slugs and snails.

Planting in sucession
 As crops have been harvested the ground has been dug over, manure added and carefully raked to make a seed bed.  So, this ground had the early peas in the background with the later maincrop in the foreground.
The green manure canopy is closing over - not many
weeds evident

If you look carefully you can see seedlings of Sinapsis alba 
and Veronica agrestis.  So not all the weeds have been
hoed out

But you can't see 'em when the green manure forms a canopy
October 2012.  It looks a little more untidy in December 2012
because of winter rains and frost but it is doing its job. 
 This green manure will only be dug in at the last minute before next years crop plants are planted or sown.  There is some suggestion that there may be an allelopathic effect so digging in about two or three weeks before planting may be the best strategy.  My idea is to get the maximum effect possible and that means leaving the green manure until late spring before digging in.
Green manure on the old onion bed.  
Green manure on the old Lathyrus odoratus bed
I am trying to catch the nutrients from the dug in sweet pea plants because they fix nitrogen from the air.  This is an addition of nitrogen and is probably significant for a small allotment like this.  If the nutrients and the carbon can be captured in the green manure plants then there is a chance that it could be used by crop plants when they are dug in.  (The carbon will only be used to produce a really good root run here, although it can be utilized by mychorrhizal fungi in other parts of the allotment.)  This is the new brassica area so no mychorrhizal fungi will be used here in the new season.
Late sowing like this means that the plants have not grown
very much and no canopy has been formed yet

When winter tares are dug in the nitrogen that has been fixed by the bacteria and passed to the plant returns to the top soil when the tares rots down. Tares will rot down relatively quickly.

After digging over the potato bed to remove any little potatoes that I missed and added pigeon manure, I have sown green manure in rows.  There is some thought that green manure should be sown broadcast.  I see no good reason for doing this and several reasons for not doing it.

I want to keep the green manure as free from weeds as possible.  This is difficult when sowing broadcast.  When planted in lines I can get to weedy areas and remove the unwanted plants.  I can keep the green manure watered with comfrey liquid and hoe between the lines to keep the soil open and free of weeds.

I have also put this mixture of green manure on the old pea bed after adding pigeon manure.  I still have one line of Hurst Green Shaft that is producing peas so I will not be able to cover the whole area yet.  I also want to put green manure on the old leaf and root bed.  The carrots, parsnips and beetroot will stay in the ground but a lot of the leaves have gone over now so I will be removing them to put the green manure in.

Most of the vegetables have cropped much better than I thought they would.  The potatoes are washed, dried and bagged and waiting to go into the store shed.  Onions and leeks are starting to swell up and make decent plants.  The sweetcorn has produced some good cobs and the pumpkin and courgettes are producing  fruit now.  No squashes yet and no cucumbers either.

I have taken out all the stems that fruited from the raspberries and tied in all the new canes.  I await the autumn raspberries.  They will be fruiting soon.

I am leaving the sweet peas to go to seed which I will collect and plant in the autumn.

I need to take more of the swedes and kohlrabi or they will go woody.   I am finding it difficult to keep up with them. I need this area to plant the new strawberry bed so they will have to be harvested soon.  I will put straw around the strawberries again next year.  It was a great success this year.

A few more of the cabbages are ready for harvest now.

The runner and climbing French beans are cropping now.  I am getting quite a few runners even though it is a really late year.

Most of the Florence fennel and celery that is left has gone to seed.  No matter they will make good green manure.

 Carrots and beetroot are being slowly cropped.  The carrots are a little forked this year and I am not too sure why.  I did not add any manure to this bed this year.  They did get a lot of green manure and pea plants dug in last autumn though.

So overall not as bad as I thought it was going to be.  Probably the most disappointing were the sweet peas.

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