Long-Term Broadcast and Banded Phosphorus Fertilization of Corn Produced Using Two Tillage Systems
2002
Howard, Donald D. | Essington, Michael E. | Logan, Joanne
Surface-broadcasting P is a management concern in no-till (NT) corn (Zea mays L.) production. Field research was established in 1983 and continued through 1993 to evaluate broadcast and banded P applications for corn produced utilizing NT and disk-till (DT) systems on a Loring silt loam (Oxyaquic Fragiudalfs). A wheat (Triticum aestivum L.) cover was established each fall. The tillage systems were main plots with a factorial arrangement of broadcast P rates, and the N + P band treatments were subplots. Annual broadcast P rates were 0, 20, 39, and 59 kg ha⁻¹ A 22–20–0 kg ha⁻¹ N + P band was applied after planting. All plots received a total of 168 kg N ha⁻¹ each year. Disk-till yields were higher than NT yields for 5 of the 11 yr and were increased by P rates up to 39 kg ha⁻¹ No-till yields were increased with P rates up to 20 kg ha⁻¹ Yield response to banding N + P was inconsistent with year, tillage, and P rates. Three banded N + P plus broadcast P combinations equal to a broadcast P rate were applied each of the 11 yr. Yields for 5 of the 33 comparisons were increased by the banded plus broadcast P combination while three yields were reduced relative to broadcasting equal P rates. Yields for the other 25 comparisons were similar. Extractable P (EP) was increased with increased broadcast P rates, but the yield response was generally restricted to low EP situations.
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