“Early season tissue tests can further refine and fine tune fertilizer programs. With modern technology, tissue samples can be sent over-night delivery and have the data back in three days,” Alley notes.

“I like to use tissue tests late in the season after the fertility program is done and the plant is growing, for example, the corn ear leaf at silking. Look at a few samples to determine whether or not all the nutrients needed by the plant were delivered to the plant.

“That way the grower knows any loss in yield can be attributed to something other than plant nutrition,” he adds.

Right now phosphate fertilizer is extremely high. Knowing how much phosphorus is needed and putting it in a 2X2 band at a half or third rate can be effective.

The other side of that coin is that you won’t build fertility over time, but if the grower wants to be as efficient as possible for this year’s crop, then banding is an option.

Potash prices have risen steadily over the past few years, and subsequently growers have cut back on its use. In some soils in the Southeast potash deficiency is becoming a major concern.

Getting soil tests, particularly for sandier soils, is critical to know potash levels. If potassium is really needed, a grower has to get it out there, because plants won’t use nitrogen and phosphate fertilizers as efficiently as they will when potash levels are good, Alley says.

Much the same is true for sulfur deficiencies. Both go back to having a good liming program and having timely soil test information and most of all, applying the information in the optimum way, he adds.

“We’ve got good molecules, like urea, UAN (urea ammonium nitrate) and anhydrous ammonia for delivering nitrogen to the soil. But, the potential for loss to leaching and other causes is too high. These molecules have been around a long time, but we’ve got to figure out a way to make them work better,” Alley says.

Through his work with Koch Agronomic Services, the long-time Virginia Tech scientist continues to help growers find new ways to make fertilizer use, particularly nitrogen, more efficient.

“Long-term, efficiency is where the grower is going to be able to add that extra 25 to 40 bushels of corn per acre or an extra bale of cotton and ultimately where his is going to make money in this era of high prices and high input costs,” Alley says.

In addition to economics, he points out that making fertilizer more efficient will take care of most of the environmental concerns and help ease some of the restrictive regulations that growers are dealing with today.

”We essentially have two choices. We can fight these battles like we are doing with the Chesapeake Bay cleanup, or we can figure out a way to apply exactly what nutrients  a plant needs and when it needs the nutrients, and then figure out how deliver the optimum amount, leaving little if any to get into our waters,” Alley says.

rroberson@farmpress.com