Effects of Emphasis Type='Italic'>Faidherbia albida/Emphasis> canopy and leaf litter on soil microbial communities and nitrogen mineralization in selected Zambian soils

摘要

Abstract The nitrogen status of most Zambian soils is inherently low. Nitrogen-fixing trees such as Faidherbia albida ( F. albida ) could have the potential to restore soil fertility. We conducted a study to examine the role of mature F. albida trees on the soil microbial communities and overall N fertility status in Zambia. Soil samples were collected under and outside the canopies of F. albida trees in representative fields from two sites namely; Chongwe (loamy sand) and Monze (sandy loam). To assess the long term canopy effects; total N, mineral N and soil organic carbon (C~(org)) content were directly measured from soils collected under and outside the canopy. Short term litter effects were assessed by subtracting concentrations of biochemical properties of non-amended controls from amended soils with F. albida litter during an 8?week incubation experiment. We also determined N mineralization rates, microbial community structure—Phospholipid fatty acids, microbial biomass carbon, and labile organic carbon ( $${ext{C}}_{{{ext{org[K}}_{ 2} {ext{SO}}_{ 4} ]}}$$ C org[K 2 SO 4 ] ) during incubation. For the long term canopy effect, average N mineralization rate, C~(org), total N and mineral N content of non-amended soils under the canopy were (all significant at p? F. albida could be attributed to a combination of both long term modifications of the soil biological and chemical properties under the canopy as well as short term litter fall addition.