Biological Indicators of Soil Condition on the Kabanyolo Experimental Field, Uganda
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
Agriculture
Abstract
Soil biological activity is an integral characteristic reflecting the state of soil fertility, biodiversity,
and the activity of soil processes carried out by soil organisms. In Africa, studies of soil
biological properties are few compared to the agrochemical research. In this paper, we present
an assessment of multiple biochemical and microbiological properties of soil from an agricultural
field located in the African tropical savanna. We determined basal respiration, substrate-induced
respiration, C of microbial biomass, the potential activity of denitrification, nitrogen fixation activity,
and estimated prokaryotic components in the soil microbial complex by quantitative PCR.
Basal respiration of soils ranged from 0.77 0.04 to 1.90 0.23 g C-CO2 g1 h1, and substrateinduced
respiration ranged from 3.31 0.17 to 7.84 1.04 g C-CO2 g1 h1. The C reserves of
microbial biomass averaged 403.7 121.6 g C g1 of soil. The N2O emission from the upper
layer on average amounted to 2.79 ng N-N2O g1 day1, and the potential denitrification activity
reached 745 98 ng N-N2O g1 h1. The number of copies of bacterial genes varied from
(0.19 0.02) 108 to (3.52 0.8) 108 copies g1, and of archaea—from (0.10 0.01) 107 to
(0.29 0.01) 107 copies g1 of soil. These results were in good agreement with the studies in other
seasonally wet tropical regions: the biological activity was relatively low. The difference between
biological indicators of the experimental field and the reference profile were insignificant except
for nitrogen loss, which was higher in the ploughed field. Biological indicators strongly varied in
space; we explained their heterogeneity by non-uniform management practices in the course of
agrochemical field experiments in the past. The use of organic fertilisers may cause the release of
climatically active gases due to intensive microbial respiration and denitrification, but the intensity
of emission would strongly depend on the cultivation and management method.
Description
Keywords
Carbon cycle, Nitrogen cycle, Microbial biomass, Microbial diversity, Fertilisers, Soil health, Tropical savanna
Citation
Ivanova, A.; Denisova, E.; Musinguzi, P.; Opolot, E.; Tumuhairwe, J.B.; Pozdnyakov, L.; Manucharova, N.; Ilichev, I.; Stepanov, A.; Krasilnikov, P. Biological Indicators of Soil Condition on the Kabanyolo Experimental Field, Uganda. Agriculture 2021, 11, 1228. https://doi.org/10.3390/ agriculture11121228