Testing a Low Cost Apparatus to Monitor Soil Salinity in Plant Physiology Experiment Using Arduino Platform

ABSTRACT

Soil salinization is a common problem impacting plant physiology and agricultural productivities. In order to monitor soil salinization in plant physiological experiments, a salinity monitoring system – SProb – was produced to improve our understanding of plant responses to salinity, using open hardware Arduino platform. An experiment was performed and designed to calibrate and check the viability and accuracy of SProb to be used in scientific researches. Salt concentrations were manipulated to identify sensor ability in determining salt accumulation or leaching in soils. Also, two mangrove plant species were grown to identify if root presence would affect soil salt measurements. The soil osmotic potential (Ψ_s) was estimated from SProb results and correlated with predawn and midday leaf water potential (Ψ_l) of the mangrove plants, to identify if Ψ_s would affect plants water regulations. It was also shown that SProb described well the soil salt accumulation or leaching along the time, and the measurements were not affected by the presence of roots. The ranges of Ψ_s matched with the range of mangrove Ψ_l, and the Ψ_l decreased with the decrease in Ψ_s (increase in salinity). It was confirmed that the SProb sensor is efficient, cheap and has enough accuracy to monitor soil salt concentration. Thus, SProb can be used in plant physiological experiments increasing our ability to make accurate science when such technology is not available in research centers.

KEYWORDS:

• Salinization
• salt concentration
• sensor
• water potential
• soil osmotic potential

Acknowledgments

VNR was supported with a master scholarship by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001. MB was also supported by National Science Foundation (NSF) award under Grant #175483.

Declaration of interest

The authors declare no conflict of interest.

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001; National Science Foundation [1754803].

Notes on contributors

Vanessa Negrão-Rodrigues

Vanessa Negrão-Rodrigues (https://orcid.org/0000-0003-0400-9152; http://lattes.cnpq.br/9981801412404184). Biologist (IFPA), master degree in Tropical Botany (UFRA/MPEG). Develops focused research in ecology of mangrove, functional plant ecology, plant hydraulics and sensor testing for plant ecophysiology applications.

Grazielle Sales Teodoro

Prof. Dr. Grazielle Sales Teodoro (https://orcid.org/0000-0002-5528-8828; http://lattes.cnpq.br/3084958403475877). Professor at University of Pará, Belém, Pará State, Brazil; PhD in Plant Biology at UNICAMP (Brazil). Her research is focused in ecophysiology and plant functional traits, mainly in plant responses and nutrients and water use strategies in a context of climate and land use changes.

Mario J. Marques-Azevedo

MSc. Mario J. Marques-Azevedo (http://orcid.org/0000-0002-1868-5306; http://lattes.cnpq.br/1861003299209055): Biologist (UNESP) with master degree in Ecology (Unicamp). Has worked with ecological diversity to understand mechanisms of local and regional ecological patterns, specifically in plant communities along ecological gradients. Actually is CEO and Project Management member at Plantem and advocate of open source, hardware and science.

Mauro Brum

Dr. Mauro Brum (https://orcid.org/0000-0002-9790-254X; http://lattes.cnpq.br/7007334502445147). Phd in plant ecology and ecophysiology (UNICAMP). He has been researching plant water use strategies, ecological diversity to understand the mechanisms plant niche partitioning and drought tolerance strategies in tropical forests. Actually is a postdoc researcher at the University of Arizona.