Vol.:(0123456789) 1 3
Environmental Sustainability
https://doi.org/10.1007/s42398-019-00047-3
SHORT COMMUNICATION
Maize rhizosphere soil stimulates greater soil microbial biomass
and enzyme activity leading to subsequent enhancement of cowpea
growth
Ricardo Silva de Sousa
1
· Luis Alfredo Pinheiro Leal Nunes
1
· Jadson Emanuel Lopes Antunes
1
·
Ademir Sérgio Ferreira de Araujo
1
Received: 5 September 2018 / Revised: 17 January 2019 / Accepted: 20 January 2019
© Society for Environmental Sustainability 2019
Abstract
Rhizosphere from diferent plant species can infuence diferently the soil microbial biomass and activity. The aim of this
study was to evaluate the efect of rhizosphere of maize and cowpea on soil microbial biomass and enzymes. Soil samples
adhered to the roots of maize were collected at 45 (fowering) and 75 (senescence) days; while for cowpea, soil samples
were collected at 35 (fowering) and 60 (senescence) days. Soil microbial biomass C was highest in soils from the rhizos-
phere of maize. The activity of dehydrogenase and β-glycosidase were highest in soils from the rhizosphere of maize, while
phosphatase was higher in soils from the rhizosphere of cowpea. This study concluded that soils from rhizosphere of maize
presented higher soil microbial biomass and enzyme activity in comparison to soils from rhizosphere of cowpea.
Keywords Microbial properties · Roots · Legumes · Gramineae · Rhizosphere
Introduction
Rhizosphere is a specifc zone surrounded by the roots that
infuence, due to their exudates, the activity of soil microor-
ganisms (Qiao et al. 2017). This zone presents high amount
of C released through rhizodeposition (Zang et al. 2015) and
these C sources strongly infuence the soil microorganisms
living in the rhizosphere (Jacoby et al. 2017). Also, the qual-
ity and quantity of these root exudates can vary according to
the plant species and development (Jones 1998). Thus, this
variation in plant species and their rhizosphere and exuda-
tion could infuence diferently the soil microbial biomass
(SMB) and activity (Wang et al. 2017).
SMB represents the highest fraction of soil biodiver-
sity and acts on several soil functions that are important
for the environmental sustainability, such as the dynamic of
organic matter and nutrient cycling (Li et al. 2018). Also,
SMB releases some enzymes that act on the biogeochemi-
cal cycles and contribute with nutrients for plants and the
microbial activity (Ren et al. 2018). Thus, the evaluation
of the status of SMB and soil enzymes becomes important
for the understanding of the infuence of diferent plants
rhizosphere on soil microbial properties. Previous studies
about rhizospheric efect on soil microorganisms have shown
that diferent plant species drive diferently the microbial
biomass and activity (Chaudhary et al. 2012; Gardner et al.
2011; van Wyk et al. 2017). Changes in root growth and
activity following the plant vegetative development, such as
fowering and senescence, can also infuence the soil micro-
bial biomass and activity (Mukherjee and Kumar 2007).
Therefore, in this study we hypothesized that (1) maize and
cowpea present diferent rhizosphere traits and would afect
the size of microbial biomass and activity; (2) the soil micro-
bial biomass and activity could be diferent during the fow-
ering and senescence. Usually, the studies have evaluated the
crop rotation with Gramineae after legume aiming to verify
the efect of legumes, mainly N fxation, on maize growth.
In contrast, this study evaluated the efect of the rhizosphere
of maize and cowpea during the fowering and senescence
on soil microbial biomass and activity.
* Ademir Sérgio Ferreira de Araujo
asfaruaj@yahoo.com.br
1
Soil Quality Laboratory, Agricultural Science Center,
Federal University of Piauí, Teresina, PI, Brazil