The Galvan Brides series.

Count Dante Galvan was ruthless. Though it broke Daisy's heart to hand over control of her family's horse farm to him, she had no alternative--she was in Dante's debt up to her ears! Part of the deal included Daisy relocating to Dante's ranch in Argentina. Daisy knew she was far too ordinary to ever become the count's wife. But could she resist Dante's demands that she repay her dues in his bed?