What software do you use to build VRT maps?

I would like something where I can enter all of my yield, soil testing, and maybe even fert. application data. Then use that data to set the criteria for building VRT maps. Basically I want to tell the software, if this area had x yield, and y soil fertility, put z fertilizer on. Seems simple but I am having trouble finding something like that in my research. Anyone have any suggestions?