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ARS Home » Research » Publications at this Location » Publication #343728
Title: Wheat yield and yield stability of eight dryland crop rotations

Author
item Nielsen, David
item Vigil, Merle

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2017
Publication Date: 3/1/2018
Publication URL: https://handle.nal.usda.gov/10113/5927807
Citation: Nielsen, D.C., Vigil, M.F. 2018. Wheat yield and yield stability of eight dryland crop rotations. Agronomy Journal. 110-594-601.doi:10.2134/agronj2017.07.0407.

Interpretive Summary: Wheat-fallow was the traditional dryland production system used in the semi-arid Central Great Plains for many decades in order to stabilize yields. During the past 40 years that system as evolved to include a diversity of other crops (corn, sorghum, canola, pea, millet, sunflower, triticale) while the frequency of fallow has decreased. Yet wheat remains the base crop for essentially all cropping systems. This experiment used a long-term record of wheat yields from Akron, CO in order to assess average yields and yield stability for eight different crop rotations varying in cropping intensity. The study results produced assessments that would help farmers to quantify the risk involved in changing their cropping systems. Wheat yields were greatest in rotations where wheat followed a fallow period and least where wheat followed millet production. Rotations ranked from most stable to least stable wheat production were WF(NT), WF(CT), WMF, WCMP, WCM, WCMF, WM, WCF. The probability of producing less than 1500 kg ha-1 was very low for rotations with wheat following fallow (about 0.03) and much higher for wheat following pea (0.35) or millet (0.48 to 0.58). Risk-averse farmers wishing to intensify their cropping system from WF should consider WMF because of its potential for producing high average wheat yields while maintaining relatively high yield stability.

Technical Abstract: The winter wheat (Triticum aestivum L.)-fallow (WF) dryland production system employed in the Central Great Plains has evolved in the past 40 years to include a diversity of other crops, with a reduction in fallow frequency. Wheat remains the base crop for essentially all cropping systems. Decisions to change a farming system benefit from information about average wheat yields, yield stability, and probabilities of obtaining a specified minimum wheat yield. The objective of this experiment was to quantify wheat yields, yield stability, and the probability of obtaining a specified minimum yield in eight dryland rotational systems varying in cropping intensity. The study was conducted over a 24-yr period at Akron. Yield stability was characterized with six stability measures. The probability of obtaining a yield less than 1500 kg ha-1 was also calculated for each rotation. Wheat yields were greatest in rotations where wheat followed a fallow period and least where wheat followed millet production. Rotations ranked from most stable to least stable wheat production (averaged over the six stability measures) were WF(NT), WF(CT), WMF, WCMP, WCM, WCMF, WM, WCF. The probability of producing less than 1500 kg ha-1 was very low for rotations with wheat following fallow (about 0.03) and much higher for wheat following pea (0.35) or millet (0.48 to 0.58). Risk-averse farmers wishing to intensify their cropping system from WF should consider WMF because of its potential for producing high average wheat yields while maintaining relatively high yield stability.