Published in Agron. J. 99:1710–1718 (2007)
©American Society of Agronomy
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Nitrogen Economy of Pulse Crop Production in the Northern Great Plains

Fran L. Walley,* George W. Clayton, Perry R. Miller, Patrick M. Carr, and Guy P. Lafond

F.L. Walley, Dep. of Soil Science, Univ. of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada; G.W. Clayton, Agriculture & Agri-Food Canada, P.O. Box 3000, Lethbridge, AB, Canada T1J 4B1; P.R. Miller, Land Resources and Environmental Sciences, 334 Leon Johnson Hall, Montana State University, Bozeman, MT 59717-3120; P.M. Carr, Dickinson Res. Ext. Ctr., North Dakota State University, 1041 State Avenue, Dickinson,ND 58601; and G.P. Lafond, Agriculture and Agri-Food Canada, Indian Head Research Farm, Box 760, Indian Head, SK S0G2K0. Received 11 Aug. 2006. *Corresponding author (


Previously published data were used to examine the N economy of pulse crops typically grown on the Northern Great Plains with the goal of assessing the potential contribution of field pea (Pisum sativum L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.), common bean (Phaseolus vulgaris L.), and faba bean (Vicia faba L.) to soil N accretion. Incremental changes in soil N associated with the pulse crops (i.e., the nitrogen increment, Ninc), were strongly correlated to N2 fixation and were highly variable. Data suggest that crops that can achieve relatively high levels of N2 fixation, such as faba bean, field pea, and lentil are more likely to contribute positively to the overall N economy, particularly when a cropping system is evaluated over a long term. In contrast, pulse crops that typically achieve only modest levels of N2 fixation such as desi and kabuli chickpea and common bean are more likely to be either N neutral or contribute to a soil N deficit. Because of extreme variability in levels of N2 fixation achieved, presumably reflecting variability in soil productivity as well as variations in local climate and weather, the Ninc of pulse crops likewise is highly variable. Thus, the N contribution to a subsequent crop is difficult to predict with any certainty, particularly on a yearly or short-term basis.