Graphene Oxide and its viability as a constituent for nanofertilizers

Raquel Saraiva^1,2,3,4,5*Quirina Ferreira^6,7Gonçalo Rodrigues^1,2Margarida Oliveira^1,3,4

• ¹Linking Landscape, Environment, Agriculture and Food, Higher Institute of Agronomy, University of Lisbon, Lisboa, Portugal
• ²Instituto Superior de Agronomia, Universidade de Lisboa, Portugal, Lisboa, Portugal
• ³Santarém Polytechnic University, School of Agriculture, Santarém, Portugal
• ⁴Research Center for Natural Resources, Environment and Society (CERNAS), Santarém Polytechnic University, School of Agriculture, Santarém, Portugal
• ⁵iNOVA4Health, NOVA Medical School|Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisboa, Portugal
• ⁶Gabinete de Inovação à Investigação Clínica - Unidade Local de Saúde de Santa Maria, Lisboa, Portugal
• ⁷Escola Superior de Tecnologia de Saúde, Instituto Politécnico de Lisboa, Lisboa, Portugal

The use of chemical fertilizers and phytochemicals is a current premise in major crops production, promoting increased production per hectare but representing at the same time a growing environmental concern. In response to this problem, this work carried out an ecotoxicity study and the characterization of the alterations that occur in soil properties by the use of graphene oxide (GO), a component involved in the formulation of new nanofertilizer and nanobiostimulant pellets for agriculture due to its good properties as a carrier and for the non-toxicity revealed in other areas. Lepidium sativum L. petri dish and pot trials were performed according to EN 16086-2 European Standard and OECD guidelines to evaluate germination, vitality, and root development. Soil parameters such as pH, EC, total organic carbon (TOC), and water holding capacity (WHC) were also monitored. to assess the plant stress to GO, and the effects on soil properties were evaluated.The parameters under study were germination, root length, Munoo-Liisa vitality index, number of leaves, fresh weight, soil total organic carbon, pH, electrical conductivity and water holding capacity. While no significant phytotoxic effects were observed at most concentrations, higher doses (2.00 mg.mL -1 ) exhibited deviations in plant behavior and TOC. These findings define preliminary safe-use thresholds for GO in agricultural applications.The results obtained reveal no significant differences in the main parameters determined although revealed some differences in behavior that could indicate a threshold for GO utilization.