|Pikul jr, Joseph|
Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/7/2005
Publication Date: 6/1/2005
Citation: Pikul Jr, J.L., Hammack, L., Riedell, W.E. 2005. Corn yield, n use and corn rootworm infestation of rotations in the northern corn belt. Agronomy Journal. 97(3): 854-863. Interpretive Summary: Crop rotation, residue, fertility, and tillage management are key tools having a direct impact on agricultural sustainability, but a definitive statement cannot always be made about the effect of management on production or sustainability. Crop rotation has been a good defense against corn rootworm damage, however rotation is not always practiced, and some rootworm populations have adapted to survive 2-year rotations Objectives of our research were to determine effect of rotation and fertilizer nitrogen: 1) corn yield, 2) nitrogen use efficiency, and 3) corn rootworm populations for northern corn belt conditions. We found that corn yield under a rotation of corn-soybean exceeded both continuous corn and a 4-year rotation when corn was fertilized for optimal yield. Under no nitrogen fertilizer yield on the 4-year rotation exceeded both continuous corn and corn-soybean rotations. Efficiency of nitrogen use was greater on the corn-soybean rotation and the 4-year rotation compared with continuous corn. Efficient use of nitrogen, by using longer rotations, can minimize potential for ground water contamination by leached nitrate. Results of our measurements to evaluate the influence of crop management practices on corn rootworm numbers suggest that corn rootworm populations (northern and western corn rootworm) were greater under corn-soybean fertilized for optimal yield compared with continuous corn. Thus, management practices fostering higher yields also favored higher corn rootworm populations, at least in those rotations conducive to corn rootworm survival.
Technical Abstract: Crop rotation may improve production efficiency and reduce fertilizer nitrogen (N) requirements for corn (Zea mays L.). Objectives were to determine effect of rotation and N on corn yield, efficiency of water use (WUE) and N use (NUE), and corn rootworm (Coleoptera: Chrysomelidae) populations (CR). Experiments were started in 1990 on a Barnes sandy clay loam. Rotations were continuous corn (CC), corn-soybean [Glycine max (L.) Merr.] (CS) and a 4-year rotation of corn-soybean-spring wheat (Triticum aestivum L.) companion seeded with alfalfa (Medicago sativa L.)-alfalfa hay (CSWA). N treatments for corn were: corn fertilized for a grain yield of 8.5 Mg/ha (highN), 5.3 Mg/ ha (midN), and no N fertilizer (noN). Average yield (1992-2003) was greatest (p=0.003) under CS and highN (7.0 Mg/ha). Yield differences (p=0.001) among rotations increased with decreased fertilizer N. Average (1992-2003) yield with noN fertilizer was 5.8 Mg/ha under CSWA, 4.5 Mg/ha under CS, and 2.8 Mg/ha under CC. NUE differed (p=0.096) only under midN ordered such that CSWA=CS>CC. WUE among rotations differed under midN and noN. Soil water (top 1.8m) for corn measured on 1 June (average of N treatments) was 55, 54, and 45 cm, respectively for CC, CS, and CSWA. For CSWA under highN, available water limited yield in 3 of 6 years. At highN, CR populations were greater under CS compared with CC, and greater at higher N fertilizer levels within CC. Rotations have potential to improve production efficiency, however there is potential for reduced corn yield after alfalfa due to less available soil water.