ARS | Publication request: Soil phosphorus status in potato fields

Submitted to: Plant Nutrition Colloquium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 17, 2009
Publication Date: August 26, 2009
Citation: He, Z., Honeycutt, C.W., Zhang, H. 2009. Soil phosphorus status in potato fields. Plant Nutrition Colloquium Proceedings. On-line publication.

Technical Abstract: Potato crops generally require high amounts of phosphorus (P) fertilizer to reach economically acceptable yields. However, high inputs of P not only increase production cost, but also may increase the environmental risk of P runoff. We evaluated soil test P and sequentially-extracted P in soil samples from 10 potato fields which had three-year crop rotations with or without irrigation. Whereas soil test (Olsen) P was not significantly influenced by crop rotation and irrigation, P levels in sequentially-extracted fractions were impacted by management. The impact of crop rotation was mainly expressed on water extractable P. Irrigation had greater influence on stable P extracted in NaOH and HCl fractions. Higher levels of NaOH extractable inorganic P were observed in soil from irrigated fields, while higher levels of HCl extractable P were observed in soils under rainfed management. Our data indicate that crop management practice may eventually affect P availability and runoff potential in these potato soils over the long term. However, more field data from longer experimental periods are needed to confirm this hypothesis.