Available Phosphorus Status of Nebraska Soils in Relation to Series Classification, Time of Sampling and Method of Measurement¹

Effects of Tillage System and Nitrogen Supply on Sugarbeet Production

“…These data were used to determine the parameter Spring Soil Residual N (NO 3 -N and NH 4 -N). The 0 to 0.3 m soil samples were also tested for sodium bicarbonate extractable P and exchangeable K concentrations (Olson et al, 1954) to determine sugar beet requirements of these nutrients (Table 2). …”

Creeping Bentgrass Putting Green Mehlich‐3 Soil Test Phosphorus Requirements

“…Diff erent regions of the United States use diff erent soil test methods as a result of diff erences in soil properties but also as an artifact of history. Commonly used extractants include the Bray-1 in the Midwest (Bray and Kurtz, 1945), Morgan or modifi ed Morgan in the Northeast (McIntosh, 1969), Mehlich-1 in the Southeast (Mehlich, 1953), and Olsen in the western regions of the United States (Olsen et al, 1954). All of these methods rely on colorimetric determination of orthophosphate by (or a variant of) the Murphy and Riley (1962) method.…”

High‐Yielding Corn Response to Applied Phosphorus, Potassium, and Sulfur in Nebraska

“…The basis for calibration of the Bray‐1 P and Olsen P soil tests was published by Olson et al (1954), with further refinement of the interpretation of soil test results using later research results including different rates for broadcast and band application (Shapiro et al, 2003). Current UN‐L recommendations do not recommend P and K application for corn when Bray‐1 P is greater than 15 mg kg −1 and exchangeable K is greater than 124 mg kg −1 , respectively.…”