Sugarbeets (Beta vulgaris L.) have been fertilized with phosphorus (P)
in the U.S.A. for the past 30 to 40 years. During this period, numerous
studies on P fertilization rates and application methods have been conducted.
Much of this information has been summarized (12, 14, 15, 4).
Recent soil test data from England and the U.S.A. suggest that the
available P levels in many soils are sufficient for maximum root and sucrose
production without P fertilization. Detrimental effects of P fertilization
at excessive soil P levels have been reported (6, 5) but not all data support
these conclusions (12). Increasing fertilizer costs have also made it
essential that growers have adequate guidelines upon which to base fertilizer
applications. Information has been limited in Idaho for establishing
an adequate soil test P level for optimum sugarbeet production. With this
as background, we conducted two field experiments evaluating 1) the P
fertilizer requirements of sugarbeets at different soil test P levels, and 2)
the effects of P fertilization on soils already containing adequate available
P levels
