Testing the diagnosis and recommendation integrated system (DRIS) on high country white clover-based pastures

Abstract

Plant tissue analysis is useful to assay plant nutrient status, but has limitations due to changes in nutrient concentrations with physiological age, and variation between plant parts. The Diagnosis and Recommendation Integrated System (DRIS) uses nutrient ratios calculated from plant tissue analyses to evaluate plant nutrient status. It calculates indices for each nutrient, and ranks them in order of their deficiency. An exploratory assessment of DRIS has been conducted for New Zealand high country pasture using chemical analysis and yield data from field trials. In this limited assessment, DRIS consistently ranked S and P deficiencies in the same order as indicated by yield responses to fertiliser treatments. It was generally successful in distinguishing between deficient and nondeficient conditions. Results are considered to justify a more comprehensive evaluation of DRIS for New Zealand pastures. Keywords DRIS, plant analysis, P deficiency, S deficiency