Synopsis Soil moisture recharge data, moisture use patterns, and soil moisture‐corn yield relationships point to the critical dependence of corn on stored soil moisture in western Minnesota and eastern South Dakota. Significant correlations between stored soil moisture and yield of corn were found. Above‐average rainfall during the critical growth period minimized the effect of stored soil moisture. These results emphasize the need for moisture conservation in the 19‐ to 26‐inch rainfall area of the North Central States.

C ONTOUR tillage is an important practice in the control of runoff and soil erosion. It is simple, inexpensive, and in many cases easily applied. Since contouring is generally used in connection with other conservation practices, such as soil treatment, crop rotations, terracing, and strip cropping, there are few results that show the effectiveness of the practice itself. This paper reports 9 years results on the effectiveness of contour farming on a productive Corn Belt soil. In addition to surface runoff and soil loss by erosion, the authors present a preliminary report on tile flow and plant nutrient losses in the tile drainage.

Synopsis Available soil water in depths to five feet indicate water usage to the fifth foot at kernel formation. The period of highest water requirement appears to be from tasseling to kernel formation. Water requirements decreased sharply after kernel formation. Forty to 50% of the water losses during the growing season could be accounted for by evaporation.

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