Soil and Leaf Sampling in Apple Orchards

SummaryIn an investigation to determine the best ways in which to take soil and leaf samples characteristic of an orchard, 40 commercial orchards of Cox’s Orange Pippin, selected at random from the major fruit growing areas of England, were examined over a period of three years. It was found that:1. 24 cores should be taken at random throughout an orchard in such a way that rows and alleyways contribute equally. The cores should be bulked, thoroughly mixed, and a single sub-sample taken for analysis. In any given season 80 per cent, confidence limits on the resulting determinations will be ±0.24 pH units, ±4·7 p.p.m. of P, ±24·1 p.p.m. of K, and ±13·3 p.p.m. of Mg.2. For leaves taken from the middle third of current year’s extension growths in late August, a total of 100 leaves should be picked from at least five randomly selected trees. The leaves should be dried, ground, thoroughly mixed, and a single sub-sample taken for analysis. In any given season the 80% confidence limits on the resulting determinations will be ±0·22% N, ±0–01% P, ±0·17% K, ±0·18% Ca, and ±0.03% Mg, all in terms of dry matter.It was noted that according to soil and leaf analyses the nutrient levels in the majority of the orchards were at least adequate for fruit growing. There was no relationship between any single nutrient concentration in soil or leaf and tree performance.