[Jenpen]

Can someone please explain the job of the following and when and how to use-
Farmyard manure-haven't access to fresh so the stuff you  buy in bags
Composted green waste
Multipurpose compost
Compost in the heap in the allotment I just got
And do any of the above class as humus
Thanks really confused at the moment 

[JayG]

They are all soil improvers and all are a source of humus (which really just means the non-mineral, i.e. organic component of soil.)

So, soil improvers rather than fertilisers as such, although farmyard manure is probably a bit richer in nutrients than the others.

Welcome to the forums! 

[mumofstig]

There's some question over composted green waste, at the moment IMO
If it's been made with waste collected from council garden waste collections it can include grass cut from lawns which have been treated with weedkiller. This stays within the compost and can cause damage to any plants grown in it. The composting business do not check their products to see if they are contaminated.

I do my best to avoid it nowadays, including bought multi-purpose compost which lists green waste on the bags.
In the past I've bought bags of compost and plants simply wouldn't grow in it, so be careful.

[victoria park]

All soil comes from eroded rocks and decomposed vegetation/living things.

Animal manure is rotting vegetation somewhat speeded up/concentrated by an animal stomach. Good fertiliser, good fibre for future nutrients. But a danger of weedkillers in the manure if not sourced properly these days. ( look up aminopyralid in particular )
Multi purpose compost, green waste, and allotment heaps are different stages of the same processes and less concentrated /advanced versions of animal manure. At least with allotment compost one knows what is in it.  All composts have humus at some level.

Most animal manures get spread in the autumn, composts in the spring, both as a background ongoing health/structure/fertility thing. All these things are important for ongoing healthy soil with plenty of nutrients.

Extra bought general fertiliser ( such as organic blood fish and bone, chicken manure pellets or chemical growmore ) can be added around the time of planting and through to harvesting, to supplement the immediate needs of various crops.

[Barry C]

...... If it's been made with waste collected from council garden waste collections it can include grass cut from lawns which have been treated with weedkiller. This stays within the compost and can cause damage to any plants grown in it. The composting business do not check their products to see if they are contaminated.

I've put dandelion roots, couch grass, brambles, loads of ivy and goodness knows what else into my green waste bin for the council to take away over the years.  The other garden waste, the good stuff I knew would compost easy, went into to Dalek     Worth bearing in mind, you don't know what you're getting in the stuff councils have 'recycled' , it's possibly not quite as good as our own compost?

[mjg000]

I thought that the reason council waste becomes compost is because it deals with the dandelion roots etc through the heat that it creates?

[mumofstig]

Composted well, the weed roots will be killed, but heat treatment doesn't neutralize the weed killer

[Growster...]

I wouldn't trust council-made compost as far as I could chuck it.

All around here there are stands of Japanese knot weed and even worse awful stuff, and that just ain't getting anywhere near our hallowed ground at home and on The Patch!

For such cheap compost deals these days, a couple of quid on top of a council bag of unknown weeds and worse, is nothing if you're really keen to grow veg and flowers properly.

[Jenpen]

Thanks for all your replies got a better understanding of it now and what to avoid ! no doubt there will be more questions as the season goes on.

[Mum2mj]

Composted well, the weed roots will be killed, but heat treatment doesn't neutralize the weed killer

Ugh I hadn't considered this I have 3 bags at home 

[Salmo]

Composted well, the weed roots will be killed, but heat treatment doesn't neutralize the weed killer

Ugh I hadn't considered this I have 3 bags at home 

I would think the risk of damage to crops is very small considering how diluted and weed killers would be. Is there any documented evidence of this or is it just here-say? Same with Japanese knotweed surviving and infesting.

[Barry C]

I would think the risk of damage to crops is very small considering how diluted and weed killers would be. Is there any documented evidence of this or is it just here-say?

Quick search .......

https://www.rhs.org.uk/advice/profile?PID=477

[arh]

But that's manure, not compost!.

[JayG]

I believe it is possible for the composting process to inactivate weedkiller residues, but only if the facilities and processes used are the correct ones, and how do you know what sort of expertise went into making your council compost?

Having said that, I was in Sheffield's Botanic Gardens yesterday and there were several huge piles of what looked like green waste compost (i.e. lots of twiggy bits and heaven knows what else  ) which is obviously being used to add to the beds and borders, so presumably they are reasonably confident about using it.

The possibility of weedkiller-contaminated green waste compost being responsible for plant damage is described in THIS RHS article (they use the word 'occasionally', but again, there's no easy way of knowing in advance if any given batch will be safe.)

[victoria park]

One more very important option for soil improving not mentioned above are the green manure crops.

If done correctly, they are just about the best mass holistic soil improver there is for the price, with no worries of nasties whatsoever. I recommend buckwheat and the legume types for the uninitiated to get the hang of them.
Once one experiences the improvement in structure and fertility, you'll be convinced.