FIELD METHOD FOR ESTIMATING NITRATE, PHOSPHATE, AND POTASSIUM IN PLANTS

Abstract

Introduction W1"ork on tomato and lettuce plants (2) indicates that the percentage of a plant-food element in the mature conducting tissue of a plant is a better index of the adequacy of the soil in supplying this element to the plant than is the percentage of the element found in the soil. Therefore quick tests for approximating the percentages of nitrate, phosphate, and potassium in mature plant tissue, in the field, should have practical value in supplying information to guide the application of fertilizers, either to the growing crop or for the benefit of a crop to follow. The procedures described in this paper, which are adaptations of good laboratory procedures, seem to be satisfactory for the purpose indicated.