Quantitative measurement of fertilizer uptake by crops.

Abstract

Little justification exists for using crop yield as an indirect measure of fertilizer uptake. Most commonly, fertilizer uptake is measured by the difference in nutrient yield of a crop growing in the presence or absence of fertilizer. The method recommended, (using isotopically labelled fertilizer) dispenses with the need for control plots. Application of the isotopic method to comparative studies on the placement, timing and nature of the fertilizer, to the measurement of fertilizer uptakes in the presence or absence of plant-fertilizer interactions, to the measurement of symbiotic N fixation by legume crops and to the fertilizer uptake by tree crops is discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)