Humic acid-modified bentonite composite material enhances urea-nitrogen use efficiency.

Area of Science:

• Materials Science
• Soil Science
• Environmental Chemistry

Background:

• Bentonite is a clay mineral with potential applications in agriculture.
• Humic acid (HA) can modify clay properties.
• Efficient nitrogen utilization is crucial for crop production.

Purpose of the Study:

• To modify bentonite by incorporating humic acid (HA).
• To investigate the adsorption properties of modified bentonite for ammonium (NH4+).
• To evaluate the impact of modified bentonite on nitrogen use efficiency in wheat cultivation.

Main Methods:

• Bentonite modification with humic acid.
• Characterization using FT-IR, SEM, XRD, and TGA.
• Ammonium (NH4+) adsorption studies.
• Evaluation of nitrogen leaching, volatilization, and plant uptake in soil.

Main Results:

• Humic acid successfully entered bentonite interlayers, increasing interlayer distance.
• Modified bentonite showed significantly higher NH4+ adsorption (96.4%) compared to natural bentonite (57.0%).
• Adsorption followed pseudo-second order kinetics and Langmuir isotherms, indicating favorable chemisorption.
• Modified bentonite reduced nitrogen loss in soil and enhanced wheat yield and nitrogen uptake when combined with urea.

Conclusions:

• Humic acid-modified bentonite is an effective adsorbent for NH4+.
• This modified bentonite acts as a nitrogen fertilizer synergist, improving nitrogen use efficiency.
• The material shows promise for sustainable agriculture by reducing nitrogen losses and enhancing crop productivity.