Recently Soltanpour and Schwab3developed an NH4HCO3‐DTPA (AB‐DTPA) soil test to simultaneously extract NO3, P, K, Zn, Fe, Mn, and Cu. In this test carbon black was used to clear the extract for the chromotropic acid method of nitrate determination. However, use of carbon black was inconvenient due to its staining and sometimes contaminative properties. The purpose of the study reported here was to determine the effect of the elimination of carbon black from the AB‐DTPA test on the extractable levels of P, K, Zn, Fe, Mn, and Cu.