The soil on the island of Dordrecht consists of clay, heavy clay: very fertile, but hard to till. Late winter or early spring the farmers begin to prepare their land for the raising of the next crops.
Gathering from the presence of big chunks of clay, I presume the farmer of this patch has recently been plowing. He will have to do a bit more plowing and harrowing, before he can begin to sow the seeds. It is a dark, grey day and rain has been announced, so working the land with the machinery is going to be somewhat complicated.