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content, a mch higher N content, and a lowor GIN mtio
than other soil on the fill.
The above comments refer to nutrient cyoling in unimproved
3051s. If lime andor basic slag are applied on a grazd
area, mrked increases in aoil fertility occur *om enhanced
decomposition, reduction of cat formtion and improved base
status (Shaw, 1 95 8).
Liming and other soil am el ioration
treatments are usually coupled with increased atooking.
This leads to a f'u*her jncrease in the proportion of th@
herbage production which is chamellad through the anid
alld a firther reduction in the mwnt of decomposing herbage
on the soil surface loat ate, I 970, 4 972).
It also leads
to hcreaeed utilisation of relatively unpalatable species
and ult-tely
a change in sward composition towards dminance
by more palatable graminaceous sp~e5~9. Plate et al.
(1 9'731, for exaple, showed f hat e Nardus sward oauld be
changed to a palatable gms s-dominated sward using oatrolled
intensive grazing i l ime + NP + Potaeaium (K) + awface
seeding, but at R high cost.
1-e sult s in Xale s .
Jones (1 967) obtainad sindlar
From the soil consemation viewpoint, if shesg are to be kepk
in kigh rainfall areas, a management regime is requimd wfiich:
- . .
i) maintainsacontinuousproteotive coverof palatable
hsfiage plants and asswiated plant remains
+
) maintains the soil in as fertile condition and 'rPith
as good structure as possible.
Qhese requirements are at levst park- met by the H.F.R.O. '8
prwosals for a t w-past ure systea involving:
- i) imprbfrelilmt of the part of tb available pasture nhioh
can be nost acanmically improvd, that is, that on the better
sails already oarqing soms %matis-Festuoa orbracken