REVIEW OF INTERACTION OF AMMONIUM-NITRATE AND POTASSIUM NUTRITION OF CROPS

Literature review indicates that higher crop yields may be obtained with a mixture of nitrate and ammonium than with either source alone. An adequate supply of potassium enhances ammonium utilization and thus improves yields, when a mixed ammonium-nitrate nitrogen nutrition is applied. Nitrate reduction in plant tissues consumes either chemical energy and organic acids, or competes for products of photolysis. When ammonium is applied to the roots, high concentrations of it may accumulate having a strong toxic effect. Potassium activates plant enzymes functioning in ammonium assimilation and transport of amino acids. A summary of the experiments performed by the authors indicates that a mixed ammonium, nitrate and potassium nutrition affects especially N uptake and thus production of organic nitrogen compounds.