Zinc (Zn) fertilizer recommendations for rice (Oryza sativa L.) in Arkansas have been based on soil pH since the 1970s and have not accounted for the residual carryover of previous Zn fertilizer applications. Continuous application of Zn fertilizer to soil in some fields cropped to rice has resulted in very high Mehlich 3 extractable Zn (M3Zn) concentrations in soil and illustrates the need to develop improved recommendations. The objective of this research was to develop a critical M3Zn soil concentration for making Zn fertilizer recommendations to rice. The relationship between relative yield (RY), soil pH, and soil M3Zn concentration was determined from 36 Zn fertilizer studies conducted on silt loam soils between 1992 and 2000. Multiple regression analysis showed that soil pH, M3Zn concentration, and their interaction best described rice yield response to Zn fertilization. When soil pH was >5.5, a yield response to Zn fertilization was possible, but depended on the soil's M3Zn concentration. The criti...