Author Bio: M.K. Bomford is Principal Investigator and Extension Specialist in organic and sustainable vegetable production with the Kentucky State University Land Grant Program, 400 East Main Street, Frankfort, KY 40601 (E-mail: michael.bomford@kysu.edu; Web: http://organic.kysu.edu). This article draws on data collected for the author's PhD dissertation at West Virginia University. The author extends sincere thanks to committee members William Bryan, Linda Butler, Herbert Cole, James Kotcon, and Sven Verlinden for assistance, support and advice. Research was supported by Hatch funds awarded to West Virginia University's Davis College of Agriculture.
M.K. Bomford
Biointensive agriculture (BIA) is a suite of small-scale agricultural practices that include the use of high-density mixed plantings. It has been promoted to gardeners and resource-limited farmers as a sustainable organic vegetable production method that makes efficient use of land, water, and other resources. Certain crop mixtures are popularly recommended for use in BIA systems (e.g. tomato, Lycopersicon esculentum Mill., and basil, Osimum basilicum L.); others are discouraged (e.g. tomato and Brussels sprout, Brassica oleracea L.). Rain-fed BIA gardens were planted in 2001 and 2002 to compare land-use efficiency of pure stands and two-crop mixtures of tomato, basil, and Brussels sprout. Brussels sprout was the most competitive crop among the three tested, accounting for at least two-thirds of the land equivalence ratio (LER) in mixtures; basil was the least competitive component crop, accounting for less than one-third of LER. Mixtures made more efficient use of land than pure stands only in 2002, which was hotter and drier than 2001. Potential land-use efficiency of mixtures was likely underestimated in both years because the method commonly recommended for calculating inter-plant spacing in BIA mixtures tends to result in lower total density in mixtures than in segregated pure stands, and does not account for different mixture proportions. New recommendations are proposed to address these problems, and are incorporated into a companion planting spacing calculator available for download. Marketable Brussels sprout yield was poor because of excessive heat for the cool-season crop, not because of poor plant growth. The popularly recommended mixtures did not make more efficient use of land than the popularly discouraged mixture.
biointensive agriculture (BIA), companion planting, gardens, land equivalence ratio (LER), mixed cropping, relative competition intensity (RCI), resource use efficiency, resource-limited farms, small farms, soil plant analysis development (SPAD) index
Biointensive agriculture (BIA) is a suite of land-intensive small-scale agricultural practices that include the use of high density mixed plantings grown in offset rows in deeply cultivated beds fertilized with compost (Jeavons 2006). BIA is promoted as a sustainable organic vegetable production method that makes efficient use of land, water, and other resources (Jeavons 2006). Few peer-reviewed studies have been published in response to calls for formal academic analysis of BIA systems (Jeavons 2001, Medvecky