Mapping and chemical speciation of soybean seeds and seedlings treated with nickel sources

Abstract

The potential use of nanoparticles (NPs) as a nutrient for seed treatment has been bringing much interest in the scientific community. The use of NPs in agriculture is promising, but there is a lack of information about their interaction with plants as well as its potential to boost plant growth and yield. Seed treatment with cobalt, molybdenum Bradyrhizobium strains, and nickel (Ni) has been practiced to improve crops. The objective of this study will evaluate the effect of soybean seed and seedlings treatment with Ni sources: (1) Ni hydroxide - Ni(OH)2 - dimension micrometric (5µm); (2): Ni sulphate - NiSO4; and (3): Ni hydroxide - Ni(OH)2 - dimension nanometric (5nm), both at rate of 360 mg kg-1 (detectable limit of the equipment) on the Ni-absorption by plants, shoot-to-roots Ni-translocation and its distribution on plant tissues. The distribution and chemical speciation of Ni supplied to seeds and seedlings will be assayed by micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption near-edge structure (µ-XANES). All seeds treated and further germinated will be analyzed in rizoboxes during the VE and V1 phenological stages, focusing also in the roots, soil-rhizosphere, and shoots (only V1). The major motivation for this sort of physic-chemical analysis on plants subjected to NP, is required for further development of Ni-based new fertilizers, in order to either decrease the total amount applied in the soil or augmenting nutrient use efficiency, thus reducing possible constraints to the environment and human health and improving agronomic yield with lower cost to farmers. (AU)