ARS | Publication request: Landscape influences on soil nitrogen supply and water holding capacity for irrigated corn

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 30, 2012
Publication Date: July 15, 2012
Citation: Ferguson, R., Shaver, T., Ward, N., Irmak, S., Van Donk, S., Rudnick, D., Wienhold, B.J., Schmer, M.R., Jin, V.L., Francis, D.D., Adamchuck, V., Hendrickson, L. 2012. Landscape influences on soil nitrogen supply and water holding capacity for irrigated corn. In: Proceedings of International Society of Precision Agricultural. 11th International Conference on Precision Agriculture, July 15-18, 2012, Indianapolis, Indiana. 2012 CDROM.

Interpretive Summary: Irrigated corn (Zea mays L.) accounts for 58% of total annual corn production in the western Corn Belt Region. Although irrigation increases temporal yield stability, significant yield variability can exist within irrigated fields for a given year. Within-field yield variability is largely based on differences in fertility and water availability across the landscape. Technological advances for variable nitrogen (N) management and variable irrigation management are becoming available to producers but methods to determine site characteristics for efficient application of both water and N are lacking. This study was initiated in 2011 to explore interactions of landscape and soil features with water and N inputs on grain yield and water and N use efficiency. Five field locations were used across Nebraska to evaluate the effects of landscape variation, climate, and capacity for temporal and spatial management of water and N. Preliminary results in 2011 showed that at sites with significant topographic variation these features influenced grain yield as much as the rate of irrigation water or nitrogen fertilizer, indicating the importance of considering spatial variation in landscape features when optimizing rates and timing of water and nitrogen.

Technical Abstract: Water and nitrogen (N) supply to a crop can interact throughout the growing season to influence yield potential. The increasing availability of variable rate irrigation systems to growers in irrigated regions, along with existing capacity for variable rate fertilization, provides the opportunity for temporal and spatial management of inputs of water and nitrogen. This study was initiated in 2011 to explore interactions of landscape and soil features with water and N inputs on grain yield and water and N use efficiency. Five field locations were used across Nebraska to evaluate the effects of landscape variation, climate, and capacity for temporal and spatial management of water and N. Preliminary results in 2011 showed that at sites with significant topographic variation these features influenced grain yield as much as the rate of irrigation water or nitrogen fertilizer, indicating the importance of considering spatial variation in landscape features when optimizing rates and timing of water and nitrogen.