I guess it's whether a cultivator or a woeler; both serve to loosen the ground

Use internet reference 1 & 2 to see a cultivator or a woeler

These machines have quite loose, often springy forks / prongs to loosen the soil. A woeler is used between rows of plants, wheras a cultivator might be used to loose the soil 'at random' because there is no crop in here; instead it's used to make a seedbed or -plot.

Next to thes it could be a diepwoeler, which has far more sturdy prongs to loosen / breath a more tight soil to a deeper level.

See internet reference 2 to see all the machines.

So the Tiefenlockerer and Untergrundlockerer are diepwoelers in my opinion, whereas the Spurlockerer is a cultivator, I guess

The website contains a wealth of information on the subject of sowing machines; dozens of pages, so there may be a better answer there than what I found.

Het oprullen van de grond.
Na het ploegen kan de grond opegeruld worden. Worden de grote harde stukken grond opgeruld. Is weer iets anders als eggen, waarbij de grond fijn korrelig en egaal getrokken wordt.
Lockeren is soepen en doorlaatbaar maken> oprullen.( misschien een verouderde term).