Comparison of Phosphorus Use Efficiency Among Wheat Cultivars.

Phosphorus (P) is the second most limiting plant nutrient, with 5.7 billion hectares being P deficient worldwide. As the price of P continues to increase, there is a need for more P efficient crops to increase yields on P deficient soils and conserve limited P resources. Most soils have a large amount of total P (100-1500 mg kg^-1), yet only a small portion is plant available, as currently estimated by an agronomic P test such as Mehlich-3 (M3).  However, certain varieties of plants have been noted as being “P efficient” with the ability to extract and uptake this relatively “non-labile” pool through a variety of mechanisms.  The objective of this study was to assess P use efficiency among various wheat cultivars. Twenty-two different winter wheat cultivars were grown in two P deficient soils; calcareous and non-calcareous.  After 4 weeks in a growth chamber, roots and shoots were harvested with total biomass measured. Results from this study will provide producers working on low P soils, as well as breeders working to improve the P use efficiency of their wheat lines, with new insight and tools to address the ever growing P deficiency throughout the world.