green manure on top of horse manure?

Hi everyone,

I'm converting a lawn to a no-dig perennial vegetable patch in Southampton, England.

I have removed the grass turf, forked the soil underneath to relieve soil compaction, replaced the turf (upside down) and covered the whole lot with a 5cm layer of well-rotted horse manure.

Given that the surface is now pure horse manure, is there any scope for growing a nitrogen-fixing soil improvement crop? In my seed box I have the following soil-improvers: white clover, red clover, buckwheat, phacelia, garden peas.
It seems to me that most of these 'green manure' crops involve broadcast sowing thousands of smalls seeds over an area. Am I right in thinking that won't work here, because the horse manure won't support them?
Would I be wasting seed if I try it?

Regards,
Paul

My first thought is "why wouldn't the horse manure support them?" and my second thought is one never wants to leave bare soil exposed.
I would definitely sow cover crop mix on that ground, because it should not be left bare.

Thanks for the reply Peter.

Peter Ellis wrote:My first thought is "why wouldn't the horse manure support them?"

In the past I have found that a thick layer of horse manure stops weed seedlings getting established between my food plants. (And the dung-heap does not have many weeds growing on it at the stables where I get it from.)

Peter Ellis wrote:one never wants to leave bare soil exposed.
I would definitely sow cover crop mix on that ground, because it should not be left bare.

The ground is not bare soil, it is covered in 5cm of rotted horse manure.

Sounds like you have plenty nitrogen, how about growing biomass?
Tillage radishes or sunhemp maybe both?

I do not think I have heard anyone identify a compost (such as rotted horse manure) as a ground cover before. From my perspective, it does not fulfill the role of a ground cover.

This is fresh horse manure and a little hay dumped on the ground (6"-12" thick to kill grass-no digging) first week in September. Oats, wheat and peas broadcast 3rd week in September. It is a little sparse but not bad for the work I did not put into it. Picture was taken 3rd week in December. In my experience it will be a decent bed in the spring.

I think the horse manure already has enough nitrogen in it, you wouldn't want to overnitrify your soil. I'd throw some fast growing annuals (native if possible) or short-lived perennials, that you can chop and drop to build soil structure and stability. Maybe look into some dynamic nutrient accumulators as well.

it's December, not much grows in England at this time of year
rather than leave the horse manure bare (or bare but for some green manure seeds that lie dormant until eaten) I have covered it with a good thick layer of mulch made of dead leaves and a bit of leaf mould (taken from ancient broadleaf woodland - should contain some good microbes).

That kindof prevents me from growing green manure this spring (I doubt it will grow through the leaves) but I wanted to get it covered before any weeds take hold - they will be quicker than me once the weather warms up a bit

I will just make holes in the mulch and dig a nice mixed-up hole for each plant I plant (I'm planning sea beet, Portuguese kale a.k.a. collard greens, Daubenton's kale, sea kale, one or two jostaberry bushes, lots of herbs and alliums, hablizia tamnoides, swiss chard)


thanks for your input everyone