Is there a need for Bradyrhizobium yuanmingense and B. japonicum reinoculation in subsequent cropping seasons under smallholder farmers’ conditions?
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Date
2018
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Elsevier
Abstract
Reliable information on the persistence of rhizobium in soil in the absence of host between growing periods is
important in deciding whether inoculation on the same plot in subsequent seasons is necessary. This study
determined the survival of introduced rhizobium strains and predominant factors that influence the declining
rates of their populations. Bradyrhizobium yuanmingense (BR 3267) and B. japonicum (USDA 110) were manually
incorporated into soils at four different locations (Kpalga, Tanina, Tunayilli and Busa) in northern Ghana at
2.5 × 108 (log10 8.4) and 2.5 × 107 (log10 7.4) cells g−1 peat, respectively, per 6 m2
. The populations of sur viving cells were estimated at 0, 21, 42, 81, 142 and 296 days using the Most Probable Number (MPN) count
technique. Several decline functions were applied to the data with hyperbolic regression function emerging as
the option that provides the best fit for B. yuanmingense strain BR 3267 and B. japonicum strain USDA 110 at all
locations. There was no significant difference in the declining rates between the different locations; however,
there were differences in the declining rates for the sampling times. At 296 days, the numbers of surviving cells
of B. yuanmingense strain BR 3267 and B. japonicum strain USDA 110 were log10 1.9 and log10 1.7, respectively.
Native rhizobium population and soil moisture were the predominant factors that affected the survival of the
introduced strains. It is evident from the studies that these strains can survive in sufficient numbers at least
within a year; therefore, re-inoculation may not be necessary for a following season especially when using B.
yuanmingense strain BR 3267.
Description
This article is published by Elsevier, 2018 and is also available at https://doi.org/10.1016/j.apsoil.2018.04.003
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Citation
Applied Soil Ecology 128 (2018) 54–60