Darn, the first SpaceX job I am mostly qualified for but I live (and farmed) in NJ not Texas! I spent a good portion of my youth farming soybeans... until the grain embargo on the Soviet Union and some family business hijinks sunk us. This is absolutely for the tax breaks. If SpaceX buys say 1000 acres of land but doesn't intend on developing a test facility or launch site or office complex for the next 5 years, in order for the land to stay zoned "agricultural" there must be a working farm which produces a certain percentage of the property's income from agricultural activity. The tax break probably outweighs the income from leasing the land to another farmer, which is why he will become a SpaceX employee. The income from the crop must go into SpaceX's coffers. If Texas tax laws are similar to the ones up here, land leased for agriculture is taxed higher than land used by the owner to grow crops himself. My cousin leases his 80 acres to another farmer but pays higher taxes on the property than when we farmed it as a family business.