How management practices affect silicon uptake by Hordeum vulgare grown in a highly calcareous soil

Abstract

There are many studies on the beneficial effects of silicon (Si) in plants related to a decrease of stress (biotic/abiotic). The objective of the present work was to study how plant-available Si in highly calcareous soil with different soil chemical properties, amendments and growing conditions can affect Si absorption by Hordeum vulgare L. (Barley) and its biomass. Barley was cultivated under field conditions in dryland agriculture. Three treatments were compared: phytolithic biochar, compost pellets and no amendment. Greenhouse trials with the same soil and treatments were also carried out to achieve a better understanding of the dynamics in the soil–plant system under controlled growing conditions. In both experiments, physical and chemical soil and plant parameters were determined from collected samples. Results showed that the Si uptake and biomass in soils with the highest available Si (33 ± 1 mg kg−1) was 4.7-fold and 2.4-fold higher, respectively, than in soils with the lowest available Si (22 ± 1 mg kg−1). Also, with greater Si uptake there was an increase in N uptake (τ = 0.68, p < 0.01). Therefore, Si could improve N use efficiency within the plant. A strategy to improve Si values would be to use organic amendments that are enriched with Si and supply N in a form other than ammonium (NH+ 4 ). A high pH in this type of soil produces dissolution of the biogenic Si pool and low electrical conductivity values improve plant-available Si values. It is important to increase plant-available Si in highly calcareous soils as this has important implications for improving barley production.