Using liquefied biomass hydrogel to mitigate salinity in salt-affected soils

Area of Science:

• Agricultural Science
• Environmental Science
• Material Science

Background:

• Soil salinity impacts over a third of global irrigated farmland, necessitating effective mitigation strategies.
• Developing low-cost, safe, and sustainable soil amendments is crucial for agricultural productivity.
• Hydrogels show potential for soil improvement, but their efficacy in salinity management requires further investigation.

Purpose of the Study:

• To synthesize a hydrogel from liquefied sugarcane bagasse, polyvinyl alcohol, and sodium tetraborate decahydrate.
• To evaluate the effectiveness of this hydrogel in mitigating soil salinity at different application rates.
• To analyze the impact of the hydrogel on soil and porewater chemistry, including electrical conductivity (EC), pH, and ion concentrations.

Main Methods:

• Hydrogel synthesis using liquefied sugarcane bagasse, polyvinyl alcohol, and sodium tetraborate decahydrate.
• Incubation experiment with soil at two salinity levels (5 and 10 dS m⁻¹).
• Hydrogel application at rates of 0, 1, 2, and 3% (w/w) with three replications; analysis of porewater and soil samples for EC, pH, cations, and anions.

Main Results:

• Hydrogel significantly reduced porewater electrical conductivity (EC) at both 5 and 10 dS m⁻¹ salinity levels.
• Application of hydrogel led to reductions in soil concentrations of chloride (Cl⁻), phosphorus (P), calcium (Ca²⁺), and aluminum (Al³⁺).
• Hydrogel application increased porewater pH and ammonium nitrogen (NH₄-N) at high salt levels, with maximum benefits observed at 3% application rate.

Conclusions:

• The synthesized hydrogel demonstrates significant potential as a soil amendment for mitigating soil salinity.
• This biomass-derived hydrogel offers a sustainable and effective approach to managing saline soils.
• Further research into hydrogel application rates and long-term effects is warranted for practical agricultural use.