Hopes are rising in the southern Central Valley that the farmland expected to be fallowed in coming years because of drought and groundwater restrictions won’t sit idle but will instead be consolidated to make room for new land uses including solar power generation. Efforts are underway locally to create a system for piecing together parcels that would allow investment at a scale large enough to support substantial photovoltaic solar arrays — or ranching or creation of natural habitat, whatever makes sense financially for landowners.