Fall and Spring Phosphorus Fertilization of Potato Using a Dicarboxylic Acid Polymer (AVAIL®)

Abstract

A dicarboxylic acid polymer (AVAIL) modifies the soil immediately around fertilizer—potentially improving crop phosphorus (P) uptake efficiency and yield. Study objectives were to evaluate potato (Solanum tuberosum L.) response to seasonal applications of liquid and dry AVAIL blended P fertilizer on calcareous soils with low to moderate soil test P. Field experiments conducted 2005–2008 included comparisons of monoammonium phosphate (MAP; 11-52-0) broadcast and/or ammonium polyphosphate (APP; 10-34-0) liquid band applications with or without AVAIL in various fall or spring applications. AVAIL increased US No. 1 yields for selected P rate/source/timing combinations in each of the four years; increased United States No. 1 yields overall in 2006 and 2008; and increased total yield and yield of large (>284g) tubers in 2006. The greatest responses to AVAIL occurred on soils with high lime concentrations. No seasonal advantage was observed in any case.