Combined Silicon-Phosphorus Fertilization Affects the Biomass and Phytolith Stock of Rice Plants

Abstract

Phytoliths are silica bodies formed in living plant tissues. Once deposited in soils through plant debris, they can readily dissolve and then increase the fluxes of silicon (Si) toward plants and/or watersheds. These fluxes enhance Si ecological services in agricultural and marine ecosystems through their impact on plant health and carbon fixation by diatoms, respectively. Fertilization increases crop biomass through the supply of plant nutrients, and thus may enhance Si accumulation in plant biomass. Si and phosphorus (P) fertilization enhance rice crop biomass, but their combined impact on Si accumulation in plants is poorly known. Here, we study the impact of combined Si-P fertilization on the production of phytoliths in rice plants. The combination of the respective supplies of 0.52 g Si kg -1 and 0.20 g P kg −1 generated the largest increase in plant shoot biomass (leaf, flag leaf, stem, and sheath), resulting in a 1.3-fold increase compared the control group. Applying combined Si-P fertilizer did not affect the content of organic carbon (OC) in phytoliths. However, it increased plant available Si in soil, plant phytolith content and its total stock (mg phytolith pot −1 ) in dry plant matter, leading to the increase of the total amount of OC within plants. In addition, P supply increased rice biomass and grain yield. Through these positive effects, combined Si-P fertilization may thus address agronomic (e.g., sustainable ecosystem development) and environmental (e.g., climate change) issues through the increase in crop yield and phytolith production as well as the promotion of Si ecological services and OC accumulation within phytoliths.

Effects of Different Management Practices on the Increase in Phytolith-Occluded Carbon in Moso Bamboo Forests

“…SiF can significantly increase the available Si content in soils and thus the plant organs of Moso bamboo forests, which can promote the formation of phytolith since Si is an important component in phytolith. This pattern is in accordance with a recent study (Li et al, 2020b) that has showed that the addition of SiF can increase available Si in soil.…”

Agriculture increases the bioavailability of silicon, a beneficial element for crop, in temperate soils

“…Si extracted with CaCl 2 (Si CaCl2 ), acetate, acetic acid, or citrate are used as PAS proxies since the concentrations extracted by these reagents are proportional to plant Si concentration or grain yield 22 , 23 . PAS concentrations extracted by these reagents have been shown to be positively correlated with soil properties such as phytolith content 24 , pH 25 – 27 , < 2 µm fraction 7 , 28 , organic matter, and iron oxides 28 . A negative correlation between PAS and total Si content has also been documented, reflecting the predominance of low solubility minerals such as quartz in the Si pool 28 , 29 .…”

The Halotolerant Rhizobacterium—Pseudomonas koreensis MU2 Enhances Inorganic Silicon and Phosphorus Use Efficiency and Augments Salt Stress Tolerance in Soybean (Glycine max L.)

“…This adverse effect on the ions-utilizing system alters the biochemical and metabolic processes of plants when the intake of Na + exceeds its efflux through the plasma membrane channels [ 6 ]. The ionic system in plants has been reported to be extensively linked to the ideal concentration of phosphorus and silicon [ 7 ] Bargaz et al [ 8 ] reported that phosphorus (P) supplies induced salt tolerance in Phaseolus vulgaris through acquisition of K + and Ca ++ . Similarly, several literature studies have reported the role of silicon (Si) in improving plant physiology, growth, and yield [ 9 ].…”