Sulfur‐Coated Urea and Uncoated Soluble Nitrogen Fertilizers for Fescue Forage1

Abstract

AbstractField experiments were carried out during 1965–67 to compare rates, sources and times of N topdressing for ‘Kentucky 31’ fescue (Festuca arundinacea). Uncoated ammonium nitrate (AN), urea, and other readily soluble N fertilizers resulted in higher first‐cutting yields, which were higher in content of total N. Sulfur‐coated urea (SCU) resulted in lower first‐cutting and higher later‐cutting yields than did the soluble N sources. Total annual yields were usually similar with all N sources. Mixtures of AN and SCU or split applications of AN resulted in the most uniform seasonal growth and N content. Lower yields and apparent crop recovery of N from uncoated urea and urea ammonium phosphate (UAP) indicated lower efficiency of these urea‐containing N sources for topdressing, particularly at higher N rates. December, January, February, and March topdressing dates had rather similar effects on forage yields and N contents.