Patrick Carr, North Dakota State University, Dickinson Res. Ext. Ctr., 1041 State Ave., Dickinson, ND 58601, Glenn Martin, NDSU Dickinson Res. Ext. Ctr., 1041 State Ave., Dickinson, ND 58601, and Richard Horsley, PO Box 5051, North Dakota State University, North Dakota State University, Department of Plant Scienc, Fargo, ND 58105-5051.
North Dakota is the major domestic producer of field pea (Pisum sativum L.) with over 240 000 ha-1 seeded in 2006. This level of production is explained partially by the positive rotation effect of field pea on grain yield of a subsequent spring wheat (Triticum aestivum L. emend. Thell.) crop. Limited research has been conducted on quality of grain produced by spring wheat following field pea, or on the impact of rotation on grain quality across different tillage systems. Our objective was to determine the effect of field pea on grain quality of spring wheat in a wheat-pea rotation compared with wheat monoculture in clean-, reduced-, and no-till systems. The impacts of cropping strategy and tillage system on grain protein content, volume weight, and kernel weight of spring wheat were determined in a 6-yr field study in southwestern North Dakota. Grain protein content was unaffected by cropping strategy but decreased as a result of eliminating tillage by as much as 30 g kg-1, depending on the year (P < 0.05). Kernels were 2 mg kernel-1 heavier in three years when spring wheat followed field pea rather than wheat, and in four years in no-till compared with clean-till systems. Cropping strategy and tillage system did not affect grain volume weight consistently, and an interaction between these two management factors was not detected for any quality trait. Our results indicate that cereal grain quality is maintained or enhanced in a wheat-pea rotation compared with a wheat monoculture across different tillage systems.