You can also try GeoPard. We support import of soil, yield, as-applied, provide you historical imagery (from 1988), field potential maps, lidar topography & 3d. 

VRA maps can be created via multi-layer zoning or equations (you can add your formulas), Batch equations is supported. 

John Deere Ops center integrated: rx maps, work plans, bi-directional sync of data and can send any spatial layer to Ops Center (soil , topography). 

Yield cleaning&calibration, synthetic yield maps. 

Available affordable pay-as-you-go pricing model (no expensive subscriptions).