Comparison of mehlich‐1 and mehlich‐3 extractable soil boron with hot‐water extractable boron

Abstract

Abstract The standard hot water extractant for soil boron (B) was compared with two extractants currendy in use by routine soil testing laboratories, Mehlich‐1 (M‐1) and Mehlich‐3 (M‐3). If routine extractants could be used for B, it would save the time and expense required for a separate extraction. Six states (Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia) each selected 100 soil samples sent by growers to their State laboratories which were analyzed for routine properties (pH, P, K, Ca, Mg, and organic matter) and B by M‐1 or M‐3. The samples were then analyzed for hot‐water B (HWB) using a plastic pouch procedure and inductively‐coupled plasma emission spectrometry (ICP). M‐3 extracted more B than M‐1, and the correlation coefficients for M‐3 B with HWB were higher (r = 0. 82∗∗) than were M‐l with HWB (r = 0. 74∗∗). Correlations of soil properties with M‐l and M‐3 B were higher than with HWB, but none were notable with two exceptions. Extractable Ca was positively correlated...