Spatial variation of soil enzyme activities and microbial functional diversity in temperate alley cropping systems

摘要: Spatially dependent patterns in microbial properties may exist temperate alley cropping systems due to differences litter quality and microclimate areas under trees compared those the alleys. The effect of tree row location was evaluated for its impact on soil enzyme activities Biolog substrate use patterns. Soils were sampled a depth 30 cm at middle two sites: 21-year-old pecan (Carya illinoinensis)/bluegrass (Poa trivials) intercrop (Pecan site) 12-year-old silver maple (Acer saccharinum)/soybean (Glycine max)–maize (Zea mays) rotation (Maple site). Sampling done fall 2001 summer 2002. β-Glucosidase activities, expressed as average well color (AWC), richness, Shannon diversity index, total Kjeldahl nitrogen (TKN) significantly higher (P<0.05) than surface soils Pecan site. Fluorescein diacetate (FDA) hydrolytic activity also fall, but did not differ summer. At Maple site, AWC richness 2001. Soil volumetric water content temperature generally lower results this study suggest that functionally different populations be present cropped alleys which promote disparities nutrient availability necessitating differential long-term management such systems.