Effects of Uneven Spreading of Fertilizer on Crop Yields1

Abstract Bulk spreading of fertilizer does not always result in a uniform distribution over the entire area. The extent to which this distribution affects crop yield is unknown and should be investigated. As a result, nine experiments were conducted over a period of several years to determine the effects of uneven distribution of fertilizer on the yield of corn (Zea mays L.), barley (Hordeum vulgare L.), soybeans (Glycine max L.), and wheat (Triticum aestivum L.). The investigations were conducted in the three physiographic areas of Virginia (i.e., mountain, piedmont, and coastal plain). Soil types varied from thich surface phase sandy loams to a clay loam. Four spread patterns commonly obtained in farming operations and a no‐fertilizer treatment were used. In 1970, corn on Frederick silt loam and Tatum silt loam responded to fertilization, but there was no significant differences among spread patterns on Lodi loam. Significant differences in yields among spread patterns on Davidson clay loam were observed. In 1971 there was an excellent barley response to fertilizer on Norfolk sandy loam, thick surface phase, and on Davidson clay loam, but no yield differences among spread patterns. Soybeans did not respond to fertilization on Davidson clay loam. Differences in corn yields among spread patterns on Nason silt loam were significant. Corn in 1972 on Groseclose silt loam and on Norfolk sandy loam, thick surface phase, did not respond to fertilization and hence there were no differences in yields among spread patterns. Differences in crop yields within spread patterns were observed on most of the soils.