Skip to main content
ARS Home » Research » Publications at this Location » Publication #338195
Title: Intensifying a semi-arid dryland crop rotation by replacing fallow with pea

Author
item NIELSEN, DAVID
item VIGIL, MERLE

Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2017
Publication Date: 3/17/2017
Citation: Nielsen, D.C., Vigil, M.F. 2017. Intensifying a semi-arid dryland crop rotation by replacing fallow with pea. Agricultural Water Management. 186:127-138.

Interpretive Summary: Substituting pea production for the fallow period in a wheat-corn-proso millet-fallow (WCMF) dryland rotation in the semi-arid central Great Plains could make more efficient use of precipitation while protecting the soil against erosion. However, the water use by the pea may reduce subsequent wheat and corn yields and reduce net income. This study found that replacing the fallow period with pea production reduced yields of wheat and corn that followed pea, but did not affect millet yields. The net income for the WCMP rotation was 32% lower than for the WCMF rotation. Replacing the fallow phase with pea production could only be recommend as an alternative rotation if pea seed costs and nitrogen fertilizer applied to the following wheat crop could be reduced.

Technical Abstract: Increasing dryland cropping system intensity in the semi-arid central Great Plains by reducing frequency of fallow can add diversity to cropping systems and decrease erosion potential. However elimination of the periodic fallow phase has been shown to reduce yields of subsequent crops in this region. The objective of this experiment was to determine how productivity of a 4-yr WCMF rotation [wheat (W, Triticum aestivum L.); corn (C, Zea mays L.); proso millet (M, Panicum miliaceum L.); fallow (F)] was affected when the fallow phase was replaced with pea (P, Pisum sativum L.). The effect of this intensification of the WCMF rotation on the available soil water content at planting, the water use, and the yield of each crop, and on total system productivity and net income was quantified by analyzing data over a 20-yr period from a long-term crop rotation experiment at Akron, CO. Large year-to-year variations were found for available soil water at planting, water use, and yield for all four crops. Pea water use resulted in significant reductions in available soil water at planting, water use, and yield for wheat and corn, but had little effect on those quantities in the millet crop. Total production on a seed mass basis was not different between the WCMF and WCMP rotations, but system net income for the WCMP rotation was 32% lower than for WCMF. Intensification of the WCMF rotation by replacing the fallow phase with pea production could be recommended as an alternative production method if pea seed costs and nitrogen fertilizer applied to the subsequent wheat crop can be reduced.