Identifying phosphorus deficiencies

We generally target 21 ppm soil phosphorus (Mehlich III) based upon MLSN guidelines. We do not see phosphorus (P) deficiencies that frequently, but they can occur. One potentially risky situation can occur when superintendents try to suppress poa by lowering soil phosphorus levels. The idea is that low levels of P will starve the poa, and therefore allow bentgrass to outcompete it. We are currently investigating the science behind this strategy, and will report more on it in the near…