Corn yield response to phosphorus and potassium fertilization in Arkansas

摘要

Phosphorus and potassium are key nutrients for plant physiological processes and are required in large amounts for adequate corn (Zea mays L.) production. Corn is a major row crop, and up-to-date soil test-based fertilizer recommendations are requiredto enhance production and profitability. The results from 32 P and 42 K field trials evaluating irrigated corn response to fertilizer P and K rates were used to (i) correlate corn’s relative yield response to Mehlich-3 soil test P and K, (ii) determinethe frequency and magnitude of the yield response to fertilization, and (iii) calibrate fertilizer P and K rates to soil test P and K. The quadratic and linear models identified 36 parts per million (ppm) P (r2 = .68, P 35 ppm and K 120 ppm to enhance the scope of data in the analyses andimprove our understanding of corn’s response to P and K fertilization. The current thresholds defining soil test K levels perform well in interpreting soil K availability and corn’s response to K fertilization. Mehlich-3 soil test P level definitionsshould be modified to improve the accuracy of soil test-based decisions for irrigated corn. The calibration results suggest the recommended P205 and K20 rates are greater than needed to maximize yield.