The nutrition of maize in sand culture II. The uptake of nitrogen and phosphorus and its relevance to plant analysis

Abstract

The materials and methods have been described in the first paper of this series (Glover, 1953). All experiments were of 33 factorial design (Yates, 1937) involving three different levels of supply of nitrogen, phosphorus and potassium.The results of the measurements are shown graphically in Figs. 1–4 inclusive. Because of the limits set by reproduction of Figs. 1 and 2 it is impossible to show minor variations due to different treatments. Where the curves of uptake run together one broad line is used to denote this. Deviations from this line are shown where they occur. Superimposed on the figures are lines denoting the length of the tasselling and silking periods. Thus a line covering a period of, say, 10 days and bearing the symbol T shows that tasselling in the particular series was completed in that period, and the first tassel was set at the date corresponding to the start of the line.