FARMYARD MANURE

Hawera Star, Volume L, 29 November 1930, Page 11

FARMYARD MANURE

'Considerable use is being made in various! part's of flic Empire! of the Rolthamisted' process for making straw and other plant, residues into artificial farmyard manure. This is done without the use of animals and by encouraging tho de'eom'po'sition of the material by the micro-organisms already present. The .chemistry of tho process (says the! annual report of the Itothabisted Experimental 'Station) is slowly being worked out. The first constituents of the straw to be dekomlpo'sed l arc t’he hemieelluloses, then the cellolose gjos, excepting in. so far as l it is protected by a resistant layer or lignin; it is interesting tlrat cellulose, while fairly resistant to chemicals, is easily broken d'owni by certain micro-organisms. These, however, do not appear to attack the lignin, so that this constituent is left mainly undele om'pos-ed, but not. altogether unchanged. The ratio of cellulose- plus .hemieelluloses to lignin scorns to be the. dominant factor ir, determining the rate of .decomposition of 'the straw, provided sufficient available nitrogen be present.. The xylan associated with the cellulose is not unavailable,, but is decomposed only as fast as tt is exposed by removal of the encrusting cellulose layers. The small amount of pectin present in straw is not removed during normal decomposition, but only if acid conditions set in.