Bray kurtz mehlich iii ammonium bi carbonate di ethylenetriamine penta acetic acid and ammonium acetate extractions of phosphorus potassium and magnesium in 4 oklahoma usa soils
Hanlon, E.A.; Johnson, G.V.
Communications in Soil Science and Plant Analysis 15(3): 277-294
1984
ISSN/ISBN: 0010-3624
Accession: 004857830
Multi-element soil extraction solutions offer increased convenience in soil testing laboratory operations. The recently developed Mehlich III and ammonium bicarbonate-DTPA [diethylenetriaminepentaacetic acid] multi-element extraction solutions were each compared, with the more conventional Bray/Kurtz extractant for P determination, and with 1N ammonium acetate for K and Mg determinations. The latter 2 solutions are single and tri-element extractants in current use by the Oklahoma State University Soil Testing Laboratory. The Bray/Kurtz extractant was also compared with the 1N ammonium acetate for K and Mg determination. A total of 310 soil samples from 4 soil types, which included 5 long-term soil fertility experiments, were used for these comparisons. All sites have been in continuous wheat production and received various N-P-K fertilizer treatments for at least 5 yr prior to soil sampling. All soil samples were extracted in triplicate for each extractant. Extraction of elements by all solutions was highly correlated to the Bray/Kurtz and 1N ammonium acetate extractants for Oklahoma soils.