Nitrogen (N) management for sugarbeet can be very diffi cult on slowly permeable, deep soils in semi-arid regions with limited leaching. Nitrogen application rates on wheat, sorghum, and corn preceding sugarbeet were varied to de termine if economicaUy optimum N rates for those crops provide favorable residual N (RN) for sugarbeet. This pro vided a range of residual nitrate nitrogen (N03-N) levels for sugarbeet production. Sugarbeet response to a factorial combination of RN and applied N (AN)

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... tes was studied. Residual N0 3 -N following economically optimum fertiliza tion of prior crops was 1 to 67 Ib acre"!, 0-4 ft, (1 to 75 kg ha"!, 0 to 1.2 m), low enough to maximize sugarbeet quality. Sugarbeet yields near 40 ton acre"! (90 Mg ha"l) with >16% sucrose (>160 g kg"I) were produced in every experiment. Recoverable sucrose yield response to optimum AN was +101 % at RN == 10 (i.e. optimum AN doubled yield at RN = 11 kg ha"t, 0 to 1.2 m), but was never >+6% when RN