Silicon fertilization and its role in physical and chemical soil properties in Southeastern Buenos Aires

FRAYSSINET CELIA; OSTERRIETH L. MARGARITA; BORRELLI L. NATALIA; CIARLO, ESTEBAN

Conferencia; 7th International Conference on Silicon in Agriculture; 2017

Silicon is a major component in soils. In addition to playing an important role in the conformation ofmatrix aggregates and consequently in structural stability; is an essential element for the developmentof certain crops producing silicophytoliths. Although there are studies that report the effect of silicatefertilization on crops such as rice, there is no researches in soils of the Pampean Plain that havesuffered the negative effects of intense agricultural activity for more than 150 years. Within thisagricultural activity stands out the cultivation of wheat (Triticum aestivum), with an average annualproduction of 350 tons over the last 45 years. Therefore, the aim of this work is to evaluate thecontent of silicon and its role in the physical and chemical properties of agricultural soils cultivatedwith wheat in southeastern Buenos Aires. Field tests were carried out with the application of twokinds of silicate fertilizers (one powder: Silfix and another liquid: Quicksol). Surface soil sampleswere taken and morphological, physical (texture and structural stability) and chemical properties(pH, organic matter, phosphorus and available silicon content) were determined in two plant stages(vegetative and post - harvest), using standard metodologies. One-way analysis of variance wereperformed to determine the effect of fertilization on the variables measured in each trial. The resultsindicate that the contribution of Si to the soil solution would be similar for both types of appliedfertilizer (from 598 to 728 ppm.), as well as its dynamics of behavior over time. Such fertilizationwould not significantly affect the organic matter content of the soils analyzed. With regard to pHvalues, a positive relationship between pH values and the availability of silicon in solution could beinferred. Silicon fertilization could modify the availability and/or dynamics of the available phosphorusin the analyzed soils, presenting an inverse relationship since the availability of the phosphorus (P)decreases as the silicon content increases. Plots that received silicon fertilization showed values ofavailable P that ranged from 13 to 20 ppm presenting half of the content when compared to controlplots (from 20 to 42 ppm). The composition of the fertilizers, as well as their granulometriccharacteristics, could influence the slight modifications registered in the structural stability and thetexture of the fertilized soils, presenting more adequate values for both variables those plots thatreceived the fertilizer Quicksoil. Regarding the structural stability variable, it is worth noting that thedecrease in that property correlates with a higher content of silicon in solution, which could berelated to a higher release of silicon to the soil solution due to the lower stability of the aggregates.Although this work shows the first results between the effect of silicon fertilization and the physicochemical properties of typical Argiudolls of Southeastern Buenos Aires; it is necessary to deepen thestudies in order to know the effect of silicate fertilization on plant development, soil quality andbiogeochemistry in natural environments and agroecosy