Christophe wrote:
But damn, is there not a small part of the cut grass that ends in humus ????
.
If you mow regularly, young grass shoots do not produce humus:
- too rich in nitrogen
- no cellulose / lignin
- extremely low C / N ratio ...
- decompose quickly; put it on a sheet and you will see the juice flowing: it liquefies!
All ferments !
Already a hay, much more strawy, a little cellulosic (because the grass hardens its stems to carry its ears upwards), is not a good source of humus, even if it produces a little ...
It starts to get more interesting with straw and wood (BRF ...).
Composting, if it is well done, can be a "pre-humification":
- mixture of materials rich in nitrogen, fermentable, like mowing, peeling ...
- with materials rich in cellulose / lignin: straw hay, cardboard, egg packaging ...
- so as to have a balanced C / N ratio of the order of 12 to 15
- the whole ventilated and "remixed" several times: aerobic process; avoid any settling and partial drying out ...
- average humidity (that of the pressed sponge): it is necessary for the bacteria to work (a dry biomass prevents bacterial activity: drying / dehydrating is one of the oldest ways of preserving food: hay, meat, sausages. ..), but air must circulate (so not too much!) ...
Almost all the household composts I see seriously usurp this qualifier of compost : these are "rots" that have nothing to do with composting. And even less with a "pre-humification". But probably often with a "very partial methanization"!
This does not mean that they are useless: reduction in the volume of garbage cans + return to the gardens of the nutrients (minerals) they contain ...