Root Morphology and Joint Uptake Kinetics of Phosphorus, Potassium, Calcium and Magnesium in Six Eucalyptus Clones

The root assessments and nutrient uptake kinetics parameters, i.e. Vmax, Km and Cmin, are useful to characterize the efficiency of nutrients uptake, but it is generally studied for a unique nutrient at a time. In this study, we aimed to evaluate the root morphology, the kinetic parameters and the simultaneous influxes of phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in seedlings of six eucalyptus clones (58, 386, GG100, I042, I144 and VM1). Clone 386 presented a more developed root system, contrary to GG100 that had roots development quite restricted. The uptake kinetic parameters varied according to the genotypes and nutrients. VM1 was the best clone studied due to its high plasticity, i.e. it establishes easily under high or low P and K availabilities, and showed higher influxes rates of P, K and Ca. On contrary, I042 presented the lower influxes rates for P, Ca, and Mg. The joint uptake kinetics of P, K, Ca, and Mg allowed the characterization of the influx of these nutrients for the eucalyptus clones. Hence we suggest this approach in future studies for others crops, since soil solution has several nutrients that can interact with each other during the process of absorption by the roots.