General design guideline - 3,000 for a sub-compact utility, 5,000 hours for a compact utility, and 10,000 hours for a full size agricultural tractor. Here in the USA the standard rate for moldboard plowing is USD 14.62 per acre in Kansas. Most of the surrounding states - Nebraska, South Dakota, Iowa, Minnesota, recommend the Kansas State Department of Agricultural Economics publication for a general guideline but vary from there based on local conditions (fuel, soil, etc.). I use that for setting my custom harvest rates here in Minnesota. Since you said hectare, however, I assume you are not in Kansas anymore, and any place using hectare for field measure will likely have higher fuel cost. The K-State publication, available for free on line as a PDF file, has lots of historical agricultural work rates. I am especially familiar with custom grain harvesting rates having tested equipment with harvesters throughout the US for years and the numbers match my records.