Abstract:
Although Silicon (Si) is not an essential element for plant growth, Si enhances stress
tolerance, strengthens cell walls, and promotes plant growth; however, its bioavailable
forms in soil are often limited. The study investigated the effects of soil Si enrichment on
growth, root anatomy, and dry matter partitioning of rice. The experiment was conducted
in a glasshouse at the University of Peradeniya as a pot experiment, using the drought
tolerant rice variety BG250, to evaluate its response under different levels of water supply.
The soil used in the experiment belonged to Low Humic Gley. A completely randomized
design with two treatments and 20 replications was adopted, including treatments as Si
applied and not applied. As reported in the literature, a basal application of powdered
silicic acid at 3 g kg⁻¹ was incorporated into the soil for the experiment. A month after
transplanting, plants were harvested. The variables, namely, stomatal density, specific leaf
area (SLA), root dry weight, root length, root average diameter, shoot dry weight, and plant
height, were quantified. Si fertilization significantly improved shoot dry weight by 45%
compared to the non-fertilized control. Increased dry matter accumulation in shoots
relative to roots indicated significantly improved biomass allocation of 62%, which was
attributed to strengthened cell walls and better nutrient uptake. However, no significant
differences were observed in root biomass, average root diameter, SLA, or stomatal
density. Si-treated plants also showed a significant increase in height of 28%, indicating
enhanced plant vigor during the vegetative phase. These results demonstrate how Si may
improve biomass partitioning and rice growth. To evaluate the long-term effects of Si under
natural circumstances, field trials may be necessary. Moreover, future studies must
address how other nutrients interact with Si to enhance grain quality and yield.
