THE EFFECT OF N, P AND KCL FERTILIZERS ON GRAIN-YIELD AND CD CONCENTRATION OF MALTING BARLEY

A three-year field study, conducted on two Orthic Black Chernozemic so ils, investigated the effects of application of N, P and KCl fertilize rs on grain yield and Cd concentration of two cultivars of malting bar ley (Hordeum vulgare). Soil levels of N and P were good predictors of the likelihood of a yield response to fertilizer applications, while i ncreases in yield with potassium chloride (KCl) application occurred i n spite of high levels of soil K. Additions of ammonium nitrate increa sed Cd concentration in malting barley when soil nitrate levels were l ow, with increased Cd concentrations in the grain generally being asso ciated with increasing crop yields. Applications of monoammonium phosp hate or KCl tended to increase concentrations of Cd in malting barley, with the significance of the effect varying from year to year. Respon se of Cd concentration in the grain to P and KCl application was not r elated to levels of these nutrients in the soil. As the N and K fertil izer used in the study did not contain significant quantities of Cd, t he increase in Cd concentration in the grain with fertilizer applicati on was not solely a result of Cd addition as a fertilizer contaminant. The fertilizer salts may increase Cd concentration in the soil soluti on, increasing availability for crop uptake. Increased crop yield asso ciated with N application may also increase Cd accumulation through in creased root interception and enhanced mass flow.