Affiliation:
1. Agronomy Department University of Wisconsin–Madison, Wisconsin Madison USA
2. Agronomy Department University of Florida Gainesville Florida USA
3. Soil Science Department University of Wisconsin–Madison Madison Wisconsin USA
Abstract
AbstractPhosphorous (P) and potassium (K) fertilizer rate recommendations are based on soil nutrient concentrations, which can be measured using a variety of lab methods. In Wisconsin, Bray‐1 extractant is used to measure soil test P (STP) and soil test K (STK), while most neighboring states measure STP and STK using Mehlich‐3 soil test extractant. This research aims to quantify the relationship between Bray‐1 and Mehlich‐3 extraction methods for both STP and STK for silt‐loam soils in southern Wisconsin. Soil samples were collected from three fields in November 2021. STK and soil test phosphorus STP were measured using both Bray‐1 and Mehlich‐3 extraction methods. The relationship between Bray‐1 and Mehlich‐3 extractants was quantified using linear regression. Soil test phosphorus as measured using Bray‐1 extractant was linearly related to STP as measured using Mehlich‐3 extractant (p < 0.001; Adj. R2 = 0.97), and the relationship between STK results from Bray‐1 extraction and STK results from Mehlich‐3 extraction was also linear (p < 0.001; Adj. R2 = 0.91). For the same soil samples, Mehlich‐3 extractant removed slightly more P and K as compared to Bray‐1 extractant. Due to the strong linear relationship between Mehlich‐3 and Bray‐1 extractants, simple regressions can be used to estimate Bray‐1 STP or STK from a soil test report that was generated using Mehlich‐3 lab methods, and vice versa, on WI silt‐loam soils.
Reference8 articles.
1. Culman S. Fulford A. Camberato J. Steinke K. Lindsey L. LaBarge G. Watters H. Lentz E. Haden R. Richer E. Herman B. Hoekstra N. Thomison P. &Warncke D.(2020).Tri‐state fertilizer recommendations(College of Food Agricultural and Environmental Sciences Bulletin 974). The Ohio State University.
2. Calibration of Mehlich-3 with Bray P1 and Ammonium Acetate in the Tri-State Region of Ohio, Indiana and Michigan
3. Eliason R. Goos R. J. Hoskins B. Joern B. Mallarino A. Mengel D. Dahl J. Nathan M. Shaver T. Franzen D. Culman S. Gelderman R. &Peters J.(2015).Recommended chemical soil test procedures for the North Central Region the USA (North Central Regional Research Publication No. 221) (Revised). Missouri Agricultural Experiment Station SB 1001.
4. Laboksi C. A. M. &Peters J. B.(2012).Nutrient application guidelines for field vegetable and fruit crops in Wisconsin(University of Wisconsin Cooperative Extension Publication No. A2809). University of Wisconsin Cooperative Extension.