T. Dewes et E. Hunsche, Composition and microbial degradability in the soil of farmyard manure from ecologically-managed farms, BIOL AGRIC, 16(3), 1998, pp. 251-268
Compared with usual reference values, liquid cattle manure from ecologicall
y-managed farms (n = 13) had low average nutrient contents. In the case of
solid manure obtained from cattle (n = 96) and from pigs (n = 18), the prop
ortion of NH4+ in the N-total (8.4% and 10.3% respectively), the CaO conten
t (0.26% and 0.27% respectively) and, in the case of pig manure, the P2O5 c
ontent (0.57%), were all relatively low. On the other hand, the K2O content
of cattle manure (0.8%) was higher than that quoted in reference values. T
he manures from deep-litter stables had an above average content of K2O (1.
03%). The content of N-total decreased in the sequence deep litter stable >
stanchion stable > sloping floor stable. The more frequently the manure he
aps were relocated or rotated and the older they became, the mole the conte
nt of organic matter and in particular the percentage of K2O in the mineral
fraction declined.
The net mineralization of manure-C in the soil was between 6.9 and 53.1% af
ter aerobic incubation for 10 weeks, and that of N between -5.4 and 19.5%.
In the case of C, 75.2%, and in the case of N, 65.9% of the mineralization
could be explained by the amounts of cellulose, hemicellulose, lignin, free
amino acids, protein and heterocylic N compounds contained in the manures,
as well as by their C:N ratio. The organic matter of manures from sloping
floor stables was more readily and rapidly mineralized than the organic mat
ter of manures from stanchion or deep-litter stables.