A STUDY of the long-continued soil-fertility experiments of this country and of England, made by the Department of Agriculture. 1 has brought out the following important facts about crop rotation in its relation to soil productivity, as determined by the soil conditions under which these experiments are conducted:

(1) In general, crop rotation…

Two methods have been employed in evaluating the effectiveness of rotation in crop production, and in determining the additive effects of rotation and the use of fertilizers when these two farm practices are conjoined. Although in one method the evaluations are based on the increases over the yields obtained on check plots in continuous culture and…