The study looked at how different ways of preparing soil for growing sunflowers affect soil density and temperature. They tested ploughing, chisel-ploughing, disking, and no-tillage methods in Bulgaria over three years. Ploughing led to lower soil density, while minimal tillage increased density over time. No-tillage and minimal tillage methods reduced soil temperature compared to ploughing. The temperature differences between surface and deeper soil layers were smaller with less intensive tillage.