Phosphorus and zinc fertilization of corn grown in a Connecticut soil

Abstract

Deficiencies in soil zinc (Zn) may limit yield of corn (Zea mays L.) in parts of the northeastern United States. Because phosphorus (P) fertilizer is usually applied in excess of what is removed by the crop, buildup of P could reduce the plant availability of Zn. This study examines the effects of P and Zn fertilizer on yield of corn and levels of P and Zn in soil and tissue. Compared to corn that received no P or Zn, the yield of grain increased in three years when 66 kg/ha P + 0 kg/ha Zn and 66 kg/ha P + 15 kg/ha Zn was applied. When corn was fertilized with 0 kg/ha P + 15 kg/ha Zn, grain yield increased in one year. Similarly, an increase in grain yield occurred in only one year in plots fertilized with 66 kg/ha P + 15 kg/ha Zn compared to 66 kg/ha P + 0 kg/ha Zn. Increases in grain yields ranged between 5 and 22 percent for plots receiving P alone and P plus Zn, and between 5 and 10 percent for plots fertilized with Zn alone. Silage yields followed the same trends as the grain yields except they were less pronounced. Tissue and soil analyses showed significant increases in Zn in plots fertilized with Zn but little increases in P in plots fertilized with P. Zinc reductions in tissue because of P fertilizer was minimal.