Studies in soil cultivation. III. Measurements on the Rothamsted classical plots by means of dynamometer and plough

Maps of soil resistance to ploughing have been drawn up from the dynamometer readings over several seasons for the Rothamsted classical plots, carrying wheat, barley and roots respectively.

The conclusions as to the effect of manurial treatment are only of a general nature at the present stage of the work. Such differences are certainly small in comparison with the natural variations in the soil.

In the case of the Broadbalk wheat plots the drawbar pull values have been shown to have a close relationship with the clay content of the soil and with certain aspects of the soil drainage.