Group of men gathered around threshing machine in operation - wheat being fed into threshing machine - tractor pulling threshing machine across field - men feeding silage into tractor-powered silo filler - blower pipe at top of silo, silage blowing into silo - tractor-drawn plows - tractor-drawn disc followed by planter - woman washing clothes in farm yard, man driving up on tractor, woman and worker inspecting tractor - man walking across field, numerous oil derricks in background, tractor pull