Managing Phosphorous for Corn Production in On Farm Studies.

Yield response of corn to phosphorous (P) application depends on a number of factors including residual soil P level, availability of soil moisture, soil chemical and physical properties, and variety planted.  These factors also influence the accuracy of P recommendations for corn production based on soil test results.  Corn is commonly used as a rotational crop with cotton in Texas.  Updated information is needed on corn response to P recommendations across multiple growing environments and seasons.  First, second and third-year field studies were initiated in the Blacklands and Coastal Bend regions of Texas to evaluate the response of corn to P fertility management.  Supplemental P was applied where suggested to achieve soil test recommendations based on residual soil P to a 15-cm depth.  Yields at most locations were limited by a relatively dry mid season in year one and two.  Management of P applications for corn production based on current soil test recommendations appears to be optimal across seasons and locations.