Trees in alley cropping: competitors or soil improvers?
Arboles en sistema de cultivo en callejones: ¨competidores o mejorados del suelo? Outlook on Agriculture. v. 23, no. 1 p. 27-32. 1994.
Haggar, Jeremy P. CATIE-MIP, Nicabox 112, P.O. Box 52 7444 Miami, FL 33152 US.
PLANTS. MAGNOLIOPHYTA. MAGNOLIOPSIDA. LILIOPSIDA. FABACEAE. ERYTHRINA POEPPIGIANA. GLIRICIDIA SEPIUM. POACEAE. ZEA MAYS. PHASEOLUS VULGARIS. BIOLOGICAL COMPETITION. MODELS. SOIL FERTILITY. FOOD CROPS. TREES. AGROFORESTRY. COSTA RICA. CENTRAL AMERICA. TURRIALBA (CANTON). OTS. AREA DE CONSERVACION CORDILLERA VOLCANICA CENTRAL.
Agroforestry has a high potential to sustain agricultural production in the humid tropics. One specific type of agroforestry, alley cropping, has received much attention as a means of producing staple food. There is now substantial evidence that alley cropping maintains soil fertility above levels found in pure annual cropping systems. Nevertheless, competition from the trees can significantly reduce crop yields. A model is presented of how the balance between the improved soil fertility in alley cropping and competition from the trees determines the final crop performance. It is derived from an alley cropping experiment in Costa Rica with legume trees (Erythrina poeppigiana and Gliricidia sepium), maize and beans. Better understanding of the factors that determine crop yield will enable improved design and management of alley cropping systems, and may allow alley cropping to become a more reliable means of improving crop production.