Silicon addition improves plant productivity and soil nutrient availability without changing the grass:legume ratio response to N fertilization

Abstract

Silicon (Si) plays an important role in plant nutrient capture and absorption, and also promotes plant mechanical strength and light interception in alpine meadows. In this study, we conducted a field experiment to examine the effect of nitrogen (N) application, with (N + Si) and without Si (N-only), on the potential for soil nutrient and the growth of grass and legume plant functional types (pfts) in an alpine meadow. It was found that N + Si resulted in higher soil nutrient contents, leaf N and P concentrations, abundance and biomass of legume and grass PFTs than N-only. The aboveground biomass of grass (598 g m −2) and legume (12.68 g m −2) PFTs under 600 kg ha −1 ammonium nitrate (nH 4 no 3) per year addition with Si was significantly higher than that under the same level of N addition without Si (515 and 8.68 g m −2 , respectively). The grass:legume biomass ratio did not differ significantly between the N + Si and N-only. This demonstrates that Si enhances N fertilization with apparently little effect on grass:legume ratio and increases plant-available nutrients, indicating that Si is essential for the plant community in alpine meadows. Nitrogen (N) is often the primary limiting nutrient for plant growth in terrestrial ecosystems, especially in alpine meadows, where the low temperatures and short growing season limit plant growth and nutrient cycling, and thus N fertilization is widely used in these environments 1-3. Nitrogen fertilization has been reported to influence ecosystems in a variety of ways, including changes in species diversity, biomass production, nutrient availability and soil conditions 1,4-7. Silicon (Si) is important for nutrition and nutrient cycling in soil and plants, especially for grassland environments 8-10. In natural ecosystems, Si fertilization can increase plant growth, plant N use efficiency 7,11-13 and alleviate the loss of biodiversity induced by N addition 6,14. The availability of Si during plant growth not only modifies the concentration of nutrient ions such as N and phosphorus (P) in soils 15-17 , but also strongly affects growth and abundance of grass and legume species in grasslands 16,18-20. Hence, Si could play an important role in plant community composition such as plant abundance and biomass ratios of different plant functional types (PFTs), but has received little research attention 21-23. Legume species are an important PFT in grassland. Legumes not only increase soil N and plant biomass 7,12 , but also maintain a balance of dominance of grass and other non-legume species in plant community. Therefore, management involving mixing legumes with grasses provides economic and environmental benefits and is considered a sustainable intensification in grassland 17,19,24. However, to our knowledge, no studies have examined the impacts of N + Si on soil nutrient ions and growth of grass and legume PFTs (plant abundance, aboveground biomass, leaf N and P concentration) and abundance and biomass grass:legume ratios. In this study, we tested the hypothesis that there are high...

Silicon in the Soil–Plant Continuum: Intricate Feedback Mechanisms within Ecosystems

“…For sugarcane, no positive effect of Si on P nutrition was found [ 391 ]. In contrast, Xu et al [ 91 ] found no positive effect of Si on N in legumes. Overall, the positive effect of Si on plants’ P status seems to be much clearer than the effect of Si on plants’ N status.…”

“…Not only nutrients like P and N are mobilized from soils by Si [ 81 , 91 ], but also potentially toxic metals and metalloids (e.g., Al, Cr, Cd, Pb and Zn) [ 81 ] that impair plant performance if taken up [ 92 ]. However, less is known about how silicic acid potentially mobilizes metals and metalloids from different soil minerals.…”

Contribution of Nano-Silica in Affecting Some of the Physico-Chemical Properties of Cultivated Soil with the Common Bean (Phaseolus vulgaris)

“…Figure (3D ) shows that Si-NPs400 recorded the highest silicon content, 190.74 mg kg -1 , then Si-NPs300, 200, and 100 with a value of 139.81, 95.83, and 61.11 mg kg -1, respectively. Many researchers report similar results for directly increasing soil content from silicon linearly with the added amount or dosage (Ma & Takahashi, 2002;Matichenkov et al, 2020;Xu et al, 2020).…”

“…Si-NPs200 and 100 as well showed a significant increase in nitrogen content of 0.026 and 0.025, respectively. The enhancement of nitrogen content in the soil was referred to as the positive effect of silicon on the microorganisms in the soil, which improved the organic content in the soil (Bocharnikova & Matichenkov, 2010;Xu et al, 2020) and to the positive effect of silicon in reducing the nitrogen leaching from soil (Bocharnikova & Matichenkov, 2010;Matichenkov et al, 2020;Matichenkov & Bocharnikova, 2001).…”

Silicon flow from root to shoot in pepper: a comprehensive in silico analysis reveals a potential linkage between gene expression and hormone signaling that stimulates plant growth and metabolism

“…Therefore, since hormesis can also result in phenotypic changes and adaptation strategies in plants under challenging environments ( Macias-Bobadilla et al, 2020 ), this phenomenon has the potential to enhance agricultural sustainability in a changing world ( Agathokleous & Calabrese, 2019 ). Importantly, even under non-stressful environmental conditions, Si has been proven to stimulate plant growth and metabolism ( Trejo-Téllez et al, 2020 ; Xu et al, 2020 ), though its beneficial effects are more evident under stress conditions ( Ahanger et al, 2020 ; Bui, Duong & Nguyen, 2020 ; Mandlik et al, 2020 ; Singh et al, 2020 ; Vaculík et al, 2020 ).…”