Hello Karim,
You might want to use local kriging, as in:
predicted<- krigeST(values ~ 1, data, prediction.grd, v.model, nmax = 500,
stAni = 1)
The nmax parameter is the number of observations that will be used for each
location. The stAni is a parameter controlling whether observations that
are 'spatially' or 'temporally' near will be preferred.
Local kriging may also be theoretically better because it only assumes
local stationarity rather than the existence of a constant mean for the
entire domain.
Hope this helps!
Roelof