THE EFFECT OF KCL, KNO3, AND CACL, FERTILIZATION UNDER CONVENTIONAL-TILL AND ZERO-TILL SYSTEMS ON COMMON ROOT-ROT, DRY-MATTER YIELD AND GRAIN-YIELD OF HEARTLAND BARLEY

Field studies were conducted on two soil types testing low in Cl over a 4-yr period to assess the influence of K and Cl fertilization under zero (ZT) and conventional tillage (CT) management on common root rot, dry matter yield at heading, and grain yield of Heartland barley. Til lage did not influence incidence of common root rot in the 4 site-yr w here assessments could be taken. Common root rot incidence was reduced by KCl applications in 1 out of 4 site-yr. Dry matter yield at headin g and grain yields were consistently higher with ZT than with CT on th e silty clay soil, but only in 1988 on the fine sandy loam soil. The h igher yields with ZT than with CT may be due to greater moisture conse rvation under the ZT management system. Response to K or Cl applicatio ns was generally not influenced by tillage treatment. Applications of Cl had little influence on either dry matter yield at heading or grain yield, despite the low initial Cl levels in the soils. Application of fertilizers containing Cl, therefore, may not be consistently benefic ial, even on soils testing low in Cl.