# Effects and Mechanisms of Silicone Fertilizer on Salt Ion Activity in Saline–Alkaline Soils

## TL;DR

This paper explores how a new organic silicon fertilizer reduces harmful salt activity in saline-alkaline soils, helping plants grow better.

## Contribution

The study introduces an organic silicon fertilizer with Si-O-C bonds that effectively mitigates high-salt stress in soils.

## Key findings

- Organic silicon fertilizers significantly reduced salt ion activity in soil solutions.
- 5% and 10% organic silicon fertilizers were most effective in reducing sodium and chloride ions.
- XPS analysis showed silicon valence state changes due to reactions with soil components.

## Abstract

The high salt content in saline–alkali soil has a significant impact on plant nutrient absorption and water transport, severely inhibiting crop growth. Through esterification reactions, silicic acid is grafted onto humic acid to form an organic silicon fertilizer (OSiF). The unique Si-O-C bond in the material endows this new type of organic silicon-based fertilizer with the ability to effectively alleviate the harm of high-salt soil to plants. In this study, a soil column experiment was designed to systematically evaluate and compare the effects of organic silicon fertilizers with different organic silicon contents (0%, 5%, and 10%) and traditional compound fertilizers on soil water characteristics, salt ion concentration, pH value, and electrical conductivity. The results showed that the addition of an appropriate amount of organic silicon fertilizer could significantly reduce the activity of salt ions in the soil solution. Experimental data indicated that the 5% and 10% organic silicon fertilizers had the most significant effect on the consumption of major salt ions such as sodium and chloride ions. X-ray photoelectron spectroscopy (XPS) analysis revealed that the reaction of Si-O-C bonds in the soil with Lewis bases led to a shift in the valence state of the 1S electrons of silicon atoms, providing a theoretical basis for the mechanism by which silicon fertilizers alleviate high-salt stress.