Cereal ground in that corridor rents for roughly 80 to 150 euros per hectare per year under a written lease, and dryland olive often clears less than that because the operator is absorbing harvest risk you cannot price from Ohio.
The assumption doing the most work in your sketch is currency stability, not yield variability. At 4,000 euros per hectare and 120 euros annual rent, the gross yield is three percent before Spanish income tax on rental receipts, before the gestoria or land manager fee you will need because you cannot appear at an ayuntamiento yourself, and before the IBI municipal land tax, which on agricultural parcels is small but real. Strip those out and you are probably looking at a net yield below two percent on the acquisition price, which means the entire thesis rests on capital appreciation, not income.
The legal layer that most non-resident buyers underestimate is the tenant protection embedded in the Ley de Arrendamientos Rusticos. Agricultural tenants in Spain have statutory renewal rights and preemption rights on sale, which means if you want to sell the parcel, the sitting tenant has a legal right to match your buyer's price. That is not necessarily a dealbreaker, but it constrains your exit in a way that your Canton rentals do not.
The structure that occasionally makes the numbers work is buying a larger consolidated block, not scattered parcels, where you can negotiate a crop-share arrangement directly with a cooperative rather than an individual farmer, because a cooperative gives you a counterparty with accounts you can actually read. A single hectare at 3,000 euros is a curiosity; twenty to thirty hectares with an existing cooperative relationship is a different underwriting exercise.
What is your thinking on holding period, because the appreciation case is a ten-plus-year argument, and that changes whether the income drag is