Evaluation of Alternative Nitrogen Fertilizers for Corn and Winter Wheat Production

As natural gas, and thus N fertilizer, prices increase, farmers are looking for ways to decrease N costs in farming operations. To potentially alleviate this cost burden, alternative synthetic N fertilizers are available as potential management tools for increasing crop yields and N use efficiency, and decreasing volatilization. In North Carolina specifically, little data exists on these new, synthetic N fertilizer products being marketed to farmers. Therefore, we undertook a study to compare them with aqueous urea ammonium nitrate (UAN) [(NH2)(2)CO, NH4NO3] during a 2-yr field experiment. Corn (Zea mays L.) and wheat (Triticum aestivum L.) were grown in the three physiographic regions of North Carolina with four fertilizer sources (NutriSphere [Specialty Fertilizer Products, Leawood, KS], Environmentally Smart Nitrogen Polymer Coated Urea or ESN [Agrium Inc., Alberta, Canada] UCAN-23 [Yara, Tampa, FL], and UAN) at up to six fertilizer rates. The use of the alternative products did not regularly produce more corn or wheat grain compared to UAN, while wheat straw yield was greater with NutriSphere, UCAN, and UAN compared to ESN in three of four site years. Also, an aerobic incubation experiment was performed to evaluated N release profiles of the fertilizers at 25 degrees C. The study found that NutriSphere and UCAN release time was similarly to UAN, while ESN showed a slower release profile. However, any difference in release did not affect yields of spring planted corn, NutriSphere and ESN increased corn stover yields in 3 of 6 site-years. In determining whether to use these alternative N fertilizer products, farmers should consider location, climatic conditions, and fertilizer costs in comparison to UAN.