Silicon modifies C:N:P stoichiometry and improves the physiological efficiency and dry matter mass production of sorghum grown under nutritional sufficiency

Abstract

Silicon (Si) may be involved in the modification of C:N:P stoichiometry and in physiological processes, increasing sorghum growth and grain production. The objective was to evaluate the effect of Si supply on C:N:P:Si stoichiometry, physiological response, growth, and grain production of sorghum. The experiment was carried out in pots with four concentrations of Si: 0; 1.2; 2.4; and 3.6 mmol L−1 in a completely randomized design, with six replicates. Physiological attributes and dark green color index were measured and grain and biomass production were determined. Posteriorly, the plant material was ground to determine silicon (Si), carbon (C), nitrogen (N), and phosphorus (P) contents in order to analyze C:N:P:Si stoichiometry. C:Si and C:N ratios decreased at all Si concentrations applied (1.2, 2.4, and 3.6 mmol L−1) and in all plant parts studied, being lower at 3.6 mmol L−1. The lowest C:P ratios of leaves and roots were observed at 3.6 mmol L−1 Si and the lowest C:P ratio of stems was observed at 1.2 mmol L−1 Si. Si concentrations were not significant for the N:P ratio of leaves. The highest N:P ratio of stems was observed at 3.6 mmol L−1, while the lowest N:P ratio of roots was observed at 2.4 and 3.6 mmol L−1. Regardless of photosynthetic parameters, the application of 1.2 mmol L−1 Si enhanced photosynthetic rate. The application of 2.4 and 3.6 mmol L−1 enhanced stomatal conductance and dark green color index. The mass of 1000 grains was not influenced by Si applications, while Si applications at all concentrations studied (1.2, 2.4, and 3.6 mmol L−1) enhanced shoot and total dry matter, not affecting root dry matter and grain production. In conclusion, Si supply modifies C:N:P:Si stoichiometry and increases physiologic parameters, growth, development, and grain production in sorghum.

New approaches to the effects of Si on sugarcane ratoon under irrigation in Quartzipsamments, Eutrophic Red Oxisol, and Dystrophic Red Oxisol

“…The induction of a new homeostatic balance of C:N:P caused by Si under water deficit conditions also occurs in 30-day pre-sprouted seedlings [ 13 ], and 90-days [ 32 ], 150-days [ 33 ] and 160-days [ 31 ] sugarcane plants. The induction of a new C:N:P homeostasis is not only restricted in sugarcane plants, but has also been observed in forage [ 26 , 27 ], quinoa [ 35 ], wheat [ 36 ], sorghum and sunflower [ 17 , 37 ]. This helps to consolidate another benefit of Si in the cultivation of sugarcane that also occurs in sugarcane ratoons, but it is not restricted only to this crop.…”

“…A known and sustainable alternative to attenuate stress in crops is the beneficial element Si. It may also affect plants without stress [ 15 – 17 ]. An advantage of this element is its relatively low cost compared to nutrients present in conventional fertilizers [ 18 ].…”

Silicon, by promoting a homeostatic balance of C:N:P and nutrient use efficiency, attenuates K deficiency, favoring sustainable bean cultivation

“…such as Saccharum officinarum L. [ 19 , 39 , 41 – 44 ], Chenopodium quinoa Willd. [ 34 ], Sorghum bicolor (L.) Moench [ 17 , 33 ], and Triticum aestivum L. [ 35 ]. However, this is the first study to detect the role of Si in changing the stoichiometric ratio C:N:P in bean plants.…”

“…Studies have shown the role of Si in replacing C in organic compounds that make up the cell wall of plants, especially lignin and cellulose [ 32 ]. Recent research indicates that Si uptake can lead to a new homeostatic balance of C:N:P, as observed in different species such as Sorghum bicolor (L.) Moenchand, Helianthus annuus L. [ 17 , 33 ], Chenopodium quinoa Willd. [ 34 ], Triticum aestivum L. [ 35 ], Panicum maximum L. [ 36 ], Phragmites australis [ 37 ], Medicago sativa [ 38 ], and Saccharum officinarum L. [ 19 , 39 – 43 ].…”

Si Supply Could Alter N Uptake and Assimilation of Saplings—A 15N Tracer Study of Four Subtropical Species

“…Si application has the potential to alter N assimilation rates in some Si-accumulating plants, such as rice and wheat [8,21,22]. This also means that plant uptake and utilization of different forms of inorganic N could be affected by altered available Si pools following bamboo expansion.…”