Silicon concentrations in soil and bark in Irish Sitka spruce forests

Abstract

The relationship between plant‐available silicon (Si) soil concentrations and bark Si concentrations in coniferous species is poorly understood. The objectives of this research were to generate baseline data on Si concentrations in soils and bark of Sitka spruce (Picea sitchensis) seedlings in Ireland and to understand better the relationship between soil and bark Si concentrations. Seedlings were harvested from eight plantation forestry sites and two tree nurseries, and Si concentrations in the bark tissue as well as plant‐available Si concentrations in soils (CaCl2 extractant) were measured. Bark Si concentrations varied significantly between sites and were lowest [mean 790 (± 242 SD) mg kg−1 dry plant tissue] on acidic, organic rich peat soils, while the highest Si concentrations occurred in seedlings [mean 3688 (± 633 SD) mg kg−1 dry plant tissue] grown on soils with low C concentration and higher pH values (≈ 4.5 to 5.5 in H2O). Plant‐available Si soil concentrations were not related to soil C concentrations. There was a negative (but statistically not significant) relationship between plant–soil concentrations and soil pH. A significant negative relationship was observed between plant‐available soil Si concentrations and bark Si concentrations, which may be related to the presence of soil from mixed soil horizons forming the mounds that seedlings were planted on. Uptake and sequestration of Si by seedlings may have been related to the rate of growth of the seedlings, as bark Si concentrations were highest on sites that were expected to have greater seedling growth rates. The negative relationship between bark and plant‐available Si soil concentrations suggest that uptake of Si by Sitka spruce is rejective at higher concentrations.

Accumulation and partitioning of toxic trace metal(loid)s in phytoliths of wheat grown in a multi-element contaminated soil

“…Contents of total TTMs in the soil samples after digestion with a HNO3, HCl and HF mixture (6:2:1) were measured using an inductively coupled plasma mass spectrometer (ICP-MS 7900, Agilent, USA). The bioavailable contents (extractable in 0.01 mol L -1 calcium chloride (CaCl2)) of Si (Hogan et al, 2018) and TTMs (Zhou et al, 2018) in the soil were determined by colorimetric and ICP-MS methods, respectively.…”

Silicon Effects on Biomass Carbon and Phytolith-Occluded Carbon in Grasslands Under High-Salinity Conditions

“…Soil moisture content was measured using a gravimetric method by comparative weighting of the fresh and oven-dried soil samples. Aliquots of the soil samples were ground to <0.15 mm in an agate mortar and bioavailable Si was extracted using 0.01 mol L −1 calcium chloride (CaCl 2 ) solution according to a method modified from Hogan et al (2018). Briefly, 1 g of dried soil sample was mixed with 30 mL CaCl 2 solutions in 50 mL plastic centrifuge tubes.…”

Silicon nanoparticles (SiNPs) in sustainable agriculture: major emphasis on the practicality, efficacy and concerns

“…Further, the Si released from the Si-fertilizers might undergo polymerization or form complexes with metal oxides, resulting in a lower amount of plant-available Si 18 . Hogan et al 19 reported that Si release from sodium metasilicate fertilizer, Pro-Tekt (a commercially available fertilizer), and ash-based fertilizer was significantly lesser as compared to the natural source of Si such as rice husk and rice husk amendments. However, there is no doubt that the use of these silicate fertilizers has played an important role in enhancing plant growth and development under various stresses 12 .…”