Indiana CCA Conference 2019 Presentation



Nutrient Management
Wed, Dec 18, 2019
9:00am to 9:50am


Nutrient Management
Wed, Dec 18, 2019
2:00pm to 2:50pm


The University of Georgia N-P-K fertilizer recommendations for irrigated corn start with a base yield goal of 150 bu/a.  Mehlich 1 extraction is used to get the starting point for P & K and then for every 10 bu/a more yield goal an additional 12-6-10 (lb/a N-P2O5-K2O) is added to the base fertilizer recommendation.  For N, this turns out to be 1.2 lb N/bu yield goal. Since this recommendation was developed many years ago and has not been tested in recent years, a 5-year study field study was conducted to verify this recommendation.  Irrigated corn was fertilized with increasing rates of N-P-K for 150, 200, 250 and 300 bu/a yield goal levels.  When fertilized for 150 bu/a that yield was always achieved. The 200 bu/a yield goal was achieved  3 out of 5  years, the 250 yield goal 2 out of  5 years and 300 bu/a was never quite met.  Economics or ROI on fertilizer for this study will also be discussed as well as issues such as low Mg and dilution of nutrients in tissue samples depending on plant population.


Glendon Harris

University of Georgia

Dr. Harris did his undergraduate studies in agriculture at Penn State and his masters and PhD at Michigan State.  In March of 1994 Dr. Harris was hired by the University of Georgia as the statewide agronomist for soils and fertilizers. He is located on the Tifton Campus of UGA where he also teaches an undergraduate course since 2003. His main job is to train county extension agents in the area of basic soil and fertilizer science and fertilization and liming of agronomic crops.  He maintains an active extension and applied research program mainly with cotton and peanuts. Dr Harris also works closely with the fertilizer industry throughout the southeast and serves as the Educational Advisor to the Georgia Plant Food Educational Society.  His international experience includes projects and trips to South America, Australia, China and Africa. He has been promoted through the University ranks to Full Professor.