I own a plot of 20.000 m2, in Andalucia, the land is classified as Rustic Dry land.
I have had plans drawn up for the building of a single house of nealrly 200m2.
I believe that before a licence is permitted a document needs to be signed to say the land / house will be used for agricultural purposes.
I would like to know how flexible this requirment is in terms of what is classified as agricultural use and does it have to be a registered agricultural buisness.
Answering to your question, in theory, the land must be cultivated and worked as a business. This is a general rule in Andalucia region (and in other regions). But, from my experience, the way in which this rule is applied depends on each particular area, and Town Hall. It means that the Consejeria from Agriculture asks you to proof that you will cultivate the land in agricultural business in the “application” of the license. Then, when you have the license obtained, they can inspect if you finally develop this activity or not. The way in which they inspect these licenses vary from the area.
I suggest you have a personal meeting with the architect of the Town Hall to give you his personal opinion about the case. He is the one who would know how strict is the Consejeria controlling these cases in the area.