Effects of Uneven Spreading of Lime on Soil pH and Yield of Crops Grown in Rotation

Abstract

ABSTRACT ; TWO field experiments were con-ducted, beginning in 1970, on two widely different soils to determine the effects of lime spread patterns on soil pH and on the yield of crops grown in rotation. Five spread patterns, including those obtained with bulk spreaders used in normal farming operations, were used in the investigation. Yield of corn, (Zea mays L.), barley (Hordeum vulgare L.), and soybeans [Glycine max L.) grown on a Frederick cherty silt loam at Blacksburg, Va., were not significantly affected by lime spread patterns. Yields of soybeans and corn grown on a Norfolk sandy loam, thick surface phase, at Capron, Va., were affected by lime spread patterns. The initial applica-tion of lime at 225 percent of the recommended rate, resulting from non-uniform application, reduced yields in each year of the experiment because of zinc deficiency. Zinc deficiency symp-toms were quite evident on corn and soybeans. Lime application at 150 per-cent of the recommended rate appeared to have no harmful effects on yields. Soil pH increased with increased rate of lime applied. Problems arising from nonuniform lime applications in recent years have stimulated interest in methods of apply-ing liming materials. Agronomists, generally, have recognized the desirabili-ty of uniform application over a homog-eneous soil area in preference to other distribution patterns. Some investigators (Jensen and Pesek 1962a, b, c) have reported on the effects of nonuniform fertilizer distribution on crop yields. Data on effects of uneven spreading of lime on crop yields and on soil pH are not available. Bulk spreading has become a widely accepted method of fertilizer and/or lime application. Because of the labor requirement and cost involved in hand-ling and spreading lime and fertilizer, farmers each year rely more on bulk spreading by lime and fertilizer dealers. Previous work conducted at Virginia Polytechnic Institute and State Universi-ty has shown that bulk spreading does not always result in a uniform applica-tion over the entire area (Cunningham and Rowe 1962). Spreading accuracy has been increased but there is still a need for further improvement. The purpose of this investigation is, therefore, to determine the effects of uneven spreading of lime on soil pH and crop yields.