Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2003
Publication Date: 10/1/2003
Citation: Halvorson, A.D. 2003. Does phosphorus fertilizer have value beyond the year of application?. Agronomy Abstracts. CD-ROM/Computer Program.
Technical Abstract: Phosphorus fertilizer does have value beyond the year of application. Research, primarily from the northern Great Plains, shows that residual P from fertilizer can enhance crop yields for more than 16 years after application. Soil test P levels are increased by fertilizer P application, declining gradually with each crop year unless additional fertilizer P is applied. Examples of crop response to residual fertilizer P from the literature will be presented along with long-term crop response and economic comparisons between a one-time, high-rate P application and smaller crop year P applications rates. Adequate P should be applied to bring soil test P to an adequate level for near maximum crop yield potential, then reduce P fertilizer rates to a maintenance level. Having an adequate level of available soil P to maximize crop yields will give producers the flexibility to skip one or more years of P fertilization without impacting crop yields significantly. This should optimize crop yield potential and nutrient use efficiency, especially N, each crop year. Since P is rather immobile in the soil and residual P benefits crop yields for several years, P fertilization should be considered a capital improvement to the land.