Multi-Year Evaluation of Potassium Rate for Optimum Yield and Sustainability

Multi-Year Evaluation of Potassium Rate for Optimum Yield and Sustainability

Numerous soil and plant growth factors impact the amount of plant available potassium and the root uptake of potassium.  To better refine the potassium application recommendations, a three year study of potassium application rate and method was initiated to determine the long-term soil potassium levels over the three years.  The 2016 cropping season was the second of the three year study at six sites across the Cotton Belt.  This research should help identify the application rates to optimize yields and identify sustainable soil potassium levels.  Soil samples were collected to a minimum of a two feet depth at each site.  Potassium was applied via broadcast incorporated (0-0-60) or injected (0-0-15) at six inches depth at rates of 0, 40, 80, 120, and 160 lb K2O/a.  DP 1522 B2XF was planted at each location.  Leaf samples were collected at FB+2 weeks and analyzed for K levels.  Late-season plant ratings and disease incidence data were collected.  Plots were harvested, ginned, and fiber sample analyses conducted at Cotton Incorporated.  A summary of these results will be presented