You're 90% right here, but private agriculture was actually encouraged in the USSR (because it was obvious that the kolkhoz and sovkhoz system was not going to supply the country with food).
The agriculture in question was very small-scale though -- in his or her time off from the kolkhoz the farmer would work at his or her own small private plot.
(Lots of Soviets grew their own food too.)
--- On Fri, 3/6/09, SA <s11131978 at gmail.com> wrote:
>
> In integrally-planned economies like the USSR and East
> Germany, the only unplanned sectors were those that sprang
> up and were tolerated or officially ignored because they
> were useful safety valves to compensate for the failures of
> the *plans*.
>