Long-Term Effects of Nitrogen Management Practices on Grain Yield, Nitrogen Uptake, and Efficiency in Irrigated Corn

ABSTRACT

Crop management strategies that improve Nitrogen Use Efficiency (NUE) increase profits while reducing the detrimental effects on the environment associated with fertilizer nitrogen (N) loss. Effective N management should include several critical factors that are very interrelated. A study was conducted at the Panhandle Research and Extension Center, Goodwell, OK to evaluate the effects of multiple nitrogen management practices including N rate, source, time of application, methods of fertilizer and residue incorporation over a long period of time on grain yield, N uptake and NUE in irrigated corn. Fourteen treatments were evaluated in a randomized complete block design with three replicates. Results of data analyzed on the individual year and averages of all years showed that grain yield and N uptake were improved with N rates and N management practices compared to checks. Both N recovery and efficiency of use were high for the 118 kg N ha^{− 1} rate.

Keywords:

• corn
• denitrification
• immobilization
• leaching
• mineralization
• nitrogen fertilizer recovery

Notes

^†Standard error of difference of two means calculated using the equation: SQRT(MSE/r₁+ MSE/r₂). Where MSE is the mean square obtained from Analysis of Variance (ANOVA) for the error term in the model; r₁ and r₂ are number of observations per respective mean.

^† Standard error of difference of two means calculated using the equation: SQRT(MSE/r₁+ MSE/r₂). Where MSE is the mean square obtained from Analysis of Variance (ANOVA) for the error term in the model; r₁ and r₂ are number of observations per respective mean.