Phillips said producers should set realistic yield goals and fertilize accordingly. “Set a goal somewhere between average and maximum potential,” he said. “At least get in the ballpark. Yield monitoring will help.”

In-season tissue testing can improve fertility management. Phillips recommends tissue tests at growth stage 30. “Walk the fields and collect good samples.”

Crop sensors also provide in-season help for analyzing fertility needs. Philips said a sensor, such as the Green Seeker, can help improve nitrogen use efficiency. “The Green Seeker has a lot of uses including identifying weed pressure, mapping, applying plant growth regulators and defoliants for cotton.”

He also cautioned wheat producers to take care with “early season nitrogen applications. You can increase the risk of lodging, disease and damage from a late freeze. We have a very high risk of freeze damage this year. Scout fields and apply appropriate rates.”

Timing fertilizer applications should coincide with “when the crop will take it up the best. And uptake is not linear,” Phillips said. “In Kentucky, wheat needs little nitrogen from February through March. Application from late March through early April is usually better but growers can’t always go by the calendar in intensively managed wheat.”

Phillips said if the fertility rate is wrong, timing will not make much difference.

“In the Southeast, two to three split applications in the spring show significant yield advantages. Proper fertilizer timing is when the crop requirements indicate a need. Also, make certain to recognize the existing loss pathways for nitrogen.”

Fertilizer placement depends on soil dynamics and the mobility of the nutrient. “Nitrogen will move,” Phillips said. “Phosphorus and potassium are mostly taken up at the soil surface. A highly immobile nutrient such as phosphorus concentrated just below the soil surface will increase plant root activity.”

Banding may be an efficient application method.

He said nutrient mobility may account for field spatial variability. “Also, when we fertilize for the average, we rarely get it right.”

Phillips said wheat farmers interested in increasing productivity with more intensive management should incorporate “principles that drive actions away from tradition and to a scientific method of production.”