Moisture content measured in the soil correlated strongly with the curvature of the soil surface. At the concave parts of the landscape, the moisture content was as high as 14% and grain yields were as high as 1734 kg/ha. At the convex parts, the moisture content was as low as 5% and the grain yields were as low as 408 kg/ha. The correlation coefficient between the measured moisture and the calculated surface curvature was 0.9 and was significant at the 0.1% level. The observation tends to support the theory about the horizontal flow component of infiltrating water. The new theory and the supporting observations point toward an important source of nonuniformities in moisture distribution in nonleveled fields, which are far greater than those caused by common irrigation systems.