Submitted to: World Agroforestry Congress
Publication Type: Abstract Only
Publication Acceptance Date: 2/3/2014
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Alley cropping in agroforestry practices has been shown to improve soil quality, however information on long-term effects (>10 years) of alley cropping on soils in the temperate zone is very limited. The objective of this study was to examine effects of management, landscape, and soil depth on soil bulk density, water-stable soil aggregates (WSA), soil organic carbon (C), soil nitrogen (N), and soil enzyme activity of an agroforestry practice established in 1990 in northeast Missouri. The agroforestry practice consisted of silver maple (Acer saccharinum L.) intercropped with a no-till corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) rotation in the alleys. Soils from crop alleys and tree rows were collected along three transects extending from upper to lower landscape positions at 0-10, 10-20, and 20-30 cm depths in 2011. Soil enzymes assayed were fluorescein diacetate hydrolase, ß-glucosidase, ß-glucosaminidase, and dehydrogenase. Soil bulk density, WSA, C, N, and soil enzyme activities decreased with soil depth in the crop alley and tree row except for glucosaminidase. At the 20-30 cm depth C, N, and glucosidase activity parameters were similar for both crop alley and tree row. The measured soil physical and biological properties were not significantly different between crop alley and tree row. Landscape position did not significantly influence management or soil depth effects. The results of the study show that trees established in the agroforestry practice improved soil quality parameters beyond the tree row into crop alleys and up to 30 cm within the soil profile as the system matured. Results also suggest that adjustments to the alley cropping system are necessary as the tree crop matures so that the soil quality level attained under the increasing impact of the trees is maintained with compatible alley management.