Symbiotic nitrogen fixation and nutrient acquisition of three groundnut genotypes exposed to different concentrations of magnesium oxide and calcium carbonate nanoparticles

Several adverse soil or climate conditions can limit magnesium and calcium availability in soil and plant's ability to absorb nutrients. Considering this, applying magnesium and calcium to the leaves which have the highest physiological Mg and Ca demand, maybe a plausible alternative fertilization approach. Magnesium and calcium are key plant mineral elements, and they are essential for many physiological processes. Therefore, magnesium and calcium deficiency can have a significant impact on crop productivity and quality. Magnesium oxide and calcium carbonate nanoparticles were applied to three groundnut genotypes namely ICGV31096, ICGV131065 and IS-07947 through foliar application at different concentrations of 50 mg/L, 100 mg/L and 200 mg/L and negative control (untreated plants).The the seeds were inoculated with compatible groundnuts (Bradyhrizobium spp. [Arachis]) strain XS21 5×108.At 50% physiological maturity, groundnut shoots were harvested and assessed for nitrogen fixation and nutrient uptake. The results revealed that foliar application of MgO and CaCO3 nanoparticles in different concentrations significantly affected δ15N, Ndfa, N content, N-fixed, N Concentration and nutrient uptake of the three groundnut genotypes. Genotype ICGV31096 had higher δ15N, Ndfa, N content, N-fixed, and N concentration and genotype ICGV131065 recorded the most nutrient uptake of the three genotypes. These results suggest that 50 mg/L MgO and 100 CaCO3 nanoparticles application enhanced nitrogen fixation, while 200 CaCO3 improved the nutrient uptake. Therefore, the application of MgO and CaCO3 nanoparticles in adequate amounts positively affects nitrogen fixation and nutrient uptake.