Experimental Agriculture

Research Article

Intercropping Sorghum with Cowpea in Dryland Farming Systems in Botswana. II. Comparative Stability of Alternative Cropping Systems

C. W. F. Lightfoota1 p1, K. B. G. Deara1 and R. Meada2

a1 Department of Agricultural Research, PB 003, Gaborone, Botswana

a2 Department of Applied Statistics, University of Reading, Whiteknights, PO Box 217, Reading RG6 2AN, England

SUMMARY

The comparative stability of sorghum–cowpea intercropping and monocropping was assessed by determination of variances, regression against an environmental index, and probability of failure to achieve minimum levels of gross income. Significant differences between the cropping systems were not detected in any of the assessments though intercropping did have a lower probability of failure at the income levels for which risk was more than minimal. The failure of intercropping to show clearly greater stability in this study in which the environmental conditions were harsh provides a conflict with the conventional view.

(Accepted February 20 1987)

Correspondence:

p1 Present address: Fanning Systems Development Project, Eastern Ursayas, Office of the Project Director, Magsaysay Boulevard, Tacloban City 7101, Philippines.