On 29/09/2013 14:56, Derek Turner wrote:
On Sun, 29 Sep 2013 09:49:33 +0100, stuart noble wrote:


Am I right in thinking that leaf mould isn't very nutritious anyway?
Probably improves soil structure though?

Trees may not have brains but they are not stupid. They re-absorb every
last bit of 'goodness' from leaves before they drop them. What's left is
mostly complex carbohydrates (I believe) which fungi break down into
'humus', a key component of the structure of topsoils.

Most sources note that in fallen leaves the carbon:nitrogen ratio is
about 30:1. That appears to be the best ratio for recycling and
nutrient retention. If it's less than 30:1, the nitrogen is in excess
and is lost as ammonia. If it's more than 30:1, then the resulting
humus will be deficient in nitrogen.

Some plants are more efficient than others at reabsorbing carbon and
nitrogen from leaves, but if you think about it, there must be some
nitrogen returned to the soil or plants would not be able to grow (those
that can use nitrogen fixed by micro-organisms are in the minority).

--

Jeff