Biochar impact on soil properties and soil solution nutrient concentrations under cotton production

Area of Science:

• Agricultural Science
• Soil Science
• Environmental Science

Background:

• Intensive agricultural practices degrade soil health in humid subtropics.
• Biochar is a potential soil amendment to enhance soil properties and productivity.
• Sustainable agricultural practices are crucial for long-term crop production.

Purpose of the Study:

• Evaluate the impact of varying biochar application rates on soil properties.
• Assess biochar's effect on soil solution chemistry under rainfed cotton.
• Determine biochar's potential as a sustainable amendment for cotton production systems.

Main Methods:

• Field experiment with rainfed cotton (Gossypium hirsutum L.) in the Lower Mississippi Delta (2020-2022).
• Applied biochar at rates of 0, 10, 20, and 40 Mg ha⁻¹.
• Measured soil properties (bulk density, water content, aggregate stability) and soil solution chemistry (nutrient concentrations and losses).

Main Results:

• 40 Mg ha⁻¹ biochar significantly reduced bulk density and increased water content in the topsoil.
• Biochar application enhanced aggregate stability in the 0.5-1 mm and 1-2 mm fractions.
• Biochar reduced soil nitrate-nitrogen concentration and losses by 53-63% and 49-102% respectively, and phosphate-phosphorus by 14-39%.

Conclusions:

• Biochar application improves key soil physical properties.
• Biochar effectively reduces nutrient losses in soil solution, mitigating environmental impact.
• Biochar presents a viable alternative amendment for enhancing the sustainability of cotton production.