Concentrations of nutrient elements in randomly selected soil samples taken at a 3-inch depth or the depth of the surface organic pad correlated poorly (R2= < 0.34) with leaf nutrient concentrations randomly selected from the same fields. Average leaf N concentrations in 74 of 79 fields sampled were above the 1.6% standard, while leaf P was below the 0.125% standard in 62 of the 79 fields. Leaf K, Ca, and Mg concentrations were above the standards 0.400%, 0.270%, and 0.130%, respectively in all fields. The average depth of the organic pad was 2.23 cm, ranging from 0 to 10.16 cm. Seventy five percent of the fields had organic pads 0.127-2.54 cm thick and 20% greater than 2.54 cm.
In an attempt to improve correlations, leaves within a 0.01M2 quadrat were sampled from 110 clones in 10 commercial blueberry fields and leaf nutrient concentrations compared with nutrient concentrations in 3-inch soil samples taken directly beneath the quadrat. The strongest correlation was between soil Mn and leaf Mn (r2= o.59). Leaf samples, although more expensive than soil samples, appear to be a better indicator of lowbush blueberry fertilizer requirements than soil samples.