NUTRIENT CONCENTRATION CURVES FOR OATS AND BARLEY AT DIFFERENT TIMES OF PERIOD OF GROWTH

Results of pot-culture experiments with 2 oat and 4 barley varieties with a wide range of manganese or phosphorus additions to Mn- or P-deficient soils, respectively, showed that manganese and phosphorus concentration curves relating nutrient concentration to dry-matter yield had different courses for young plants compared with older plants, i.e. steeply rising curves early in the period of growth becoming concave relative to the abscissa later in the season. This implies that the basis used in estimating effects of a nutrient deficiency on dry-matter yield by means of results of chemical plant analyses will not remain the same throughout the season of growth but will vary considerably between early and late stages of growth. © 1969 Martinus Nijhoff.