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Example of variability in removal coefficients. 9 sources researched 203 data entries States represented: KS (48) IA (100) IL (9) MN (10) NJ (10) DE (7) MA (4) MD (3) PA (5) N/A (7). 60. 50. 40. Frequency. 30. 20. 10. 0. 0.15. 0.20. 0.25. 0.30. 0.35. 0.40. 0.45. 0.50.
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Example of variability in removal coefficients • 9 sources researched • 203 data entries • States represented: • KS (48) • IA (100) • IL (9) • MN (10) • NJ (10) • DE (7) • MA (4) MD (3) • PA (5) N/A (7) 60 50 40 Frequency 30 20 10 0 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 Corn grain removal (lb P O /bu) 2 5
References Heckman, J.R., J.T. Sims, D.B. Beegle, F.J. Coale, S.J. Herbert and T.W. Bruulsema. Phosphorus and potassium removal in corn. Better Crops 85(1):4-6. Karlen, D.L., R.L. Flannery, and E.J. Sadler. 1988. Aerial accumulation and partitioning of nutrients by corn. Agron. J. 80:232-242. Lockman, R.B. 1986. Statistics for high yield corn: Yield, soil test, plant analysis, and fertilizer rate data fro the Herman Warsaw farm 1980-85. Agrico Chemical Co., Washington C.H., OH. Mallarino, A.P. 1996. Evaluation of optimum and above-optimum phosphorus supplies for corn by analysis of plant parts. Agron. J. 88:376-380. Malzer, G.L., J. Orf, F. Bergsrud, J. Geadelmann, and T. Graff. 1982?. High corn and soybean yield experiments on the coarse textured, irrigated soils of Minnesota. Malzer, G.L. and R.D. Munson. 1979. Memo dated April 16, 1979 from Bob Munson to Werner Nelson. Data for Malzer's 202 bu/acre corn. Munson, R.D. 1986. Research data file, dated February 7, 1986. Reetz, H.F. and M. Sevey. 1986. Grain analysis on Herman Warsaw's 370 bu/A corn, field # 3 (South). Mike Sevey, IMC Lab in Terra Haute, ran the grain sample, Harold Reetz obtained the grain sample from Herman. Analyses faxed to Bob Munson, PPI, June 4, 1986. Schlegel, A.J. and J.L. Havlin. 1995. Corn response to long-term nitrogen and phosphorus fertilization. J. Prod. Agric. 8:181-185.