Contents lists available at ScienceDirect Soil & Tillage Research journal homepage: www.elsevier.com/locate/still Effect of silicate fertilizers on wheat and soil properties in Southeastern Buenos Aires province, Argentina. A preliminary study Celia Frayssinet a,b, ⁎ , L. Margarita Osterrieth a , L. Natalia Borrelli a,b , Mariana Fernández Honaine a,b , Esteban Ciarlo c , Patricio Heiland d a Instituto de Geología de Costas y del Cuaternario (IGCyC), FCEyN, UNMdP-CIC. IIMyC, CONICET-UNMdP, Funes 3350, Buenos Aires, Mar del Plata, 7600, Argentina b Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, Buenos Aires, Capital Federal, C1425FQB, Argentina c Universidad de Buenos Aires, Facultad de Agronomía, Cátedra de Edafología, Av. San Martín 4453, Capital Federal, 1417, Argentina d Instituto Superior de Formación Docente y Técnica N° 31, Buenos Aires, Necochea, 7630, Argentina ARTICLE INFO Keywords: Silicophytoliths Silicon biogeochemistry Pampean plain Agroecosystem management Triticum aestivum ABSTRACT Silicon is a major component in soils and is essential for the development of certain crops that produce silico- phytoliths. Although there are studies about the effect of silicate fertilizers, there is no research in soils of the Pampean Plains of Argentina. Therefore, the aim of this work was to evaluate the effect of two different sources of silicate fertilizers on plant and soil available silicon content and its role in the physical and chemical prop- erties of agricultural soils under a wheat crop in southeastern Buenos Aires province. Field tests were carried out with the application of liquid and powder silicate fertilizers. Si content was analyzed in plant material. Morphological, physical and chemical properties were determined on surface soil samples. The Si content on wheat has doubled throughout the trial. The contribution of Si to the soil solution would be similar with both silicate fertilizers and the available phosphorus content showed a negative relationship with the available Si content. Such fertilization slightly influenced the structural stability and granulometry of soils. Although this work shows the first results about the effect of silicate fertilizers in agroecosystems of Argentina, it is necessary to deepen the knowledge about their effect on plant and soil quality. 1. Introduction Silicon (Si) can be found on air particles, water bodies and soil system (Basile-Doelsch, 2006; Meunier et al., 2008; Tubana et al., 2016). Within the terrestrial environments, Si is the second element in order of abundance in the lithosphere, being relevant the contribution of silica from lithogenic origin and the derived from biological or bio- genic activity (Basile-Doelsch, 2006). In the pedosphere the content of Si averages 28% in weight, with variations between 0.5 and 48%. Within the soils, Si occurs in three phases: solid, liquid and adsorbed. The solid phase consists of crystalline, microcrystalline and amorphous forms, the first two being of lithogenic origin, while the amorphous phase is mostly associated with biological activity generating the so- called amorphous silica biomineralizations or silicophytoliths (Piperno, 1988; Gomes Coe et al., 2014; Tubana et al., 2016). These silicophy- toliths arise from the Si absorbed as monosilicic acid (H 4 SiO 4 ) via roots of the plant which is lately deposited in intra or extracellular spaces as a consequence of the plant metabolism, as it is governed by cell development and tissue maturation (Lowenstan, 1981; Sangster et al., 2001; Osterrieth, 2004). More a half of the total plant communities are silicophytolith producers, with monocotyledons being the major ones, particularly grasses (Piperno, 2006). The role of silicophytoliths in plants and agriculture has been widely recognized by scientists and farmers around the world (Epstein, 1994; Datnoff et al., 2001; Guntzer et al., 2012; Ma and Takahashi, 2002; Agostinho et.al., 2017; Walsh et al., 2018). It has been proven that they have positive effects on plant growth by stimulating photo- synthesis (Ashfaque et al., 2017), improving leaf erection, promoting growth and symbiosis with beneficial microorganisms (Izaguirre- Mayoral et al., 2017), reducing vulnerability to insect or pathogen damages (Villegas et al., 2017), improving the efficiency of nutrient´s capture, such as P, Ca, K and Mg (Struyf and Conley, 2009; De Jesus et al., 2017), increasing the resistance to saline and water stresses, promoting the carbon sequestration (Parr and Sullivan, 2011; Li et al., 2013; Song et al., 2014, 2016) and reducing the toxicity of heavy metals (Br, Cd, As, Sb, etc.) (Song et al., 2011; Raymond et al., 2016; Rizwan https://doi.org/10.1016/j.still.2019.104412 Received 11 April 2019; Received in revised form 20 August 2019; Accepted 6 September 2019 ⁎ Corresponding author at: Instituto de Geología de Costas y del Cuaternario (IGCyC), FCEyN, UNMdP-CIC. IIMyC, CONICET-UNMdP, Funes 3350, Buenos Aires, Mar del Plata, 7600, Argentina. E-mail address: cfrayssinet@agro.uba.ar (C. Frayssinet). Soil & Tillage Research 195 (2019) 104412 0167-1987/ © 2019 Elsevier B.V. All rights reserved. T