Optimizing phosphorus released in calcareous soil amended with bone char and bone ash using response surface...

Area of Science:

• Soil Science
• Agronomy
• Environmental Chemistry

Background:

• Phosphorus (P) is a critical nutrient for plant growth, but its availability in calcareous soils is often limited.
• Bone ash (BA) and bone char (BC) are potential eco-friendly sources of P, but their release dynamics need optimization.
• Understanding P release from alternative sources is crucial for sustainable agriculture and reducing reliance on synthetic fertilizers.

Purpose of the Study:

• To optimize phosphorus release from bone ash (BA) and bone char (BC) in calcareous soil compared to phosphate rock (PR) and single superphosphate (SSP).
• To evaluate the effects of different phosphorus levels (PL) and incubation times on P availability and solubility.
• To investigate the impact of distilled water (DW) and acidified water (AW) on P release and soil properties.

Main Methods:

• Central composite design and desirability function for optimization.
• Incubation experiment at 30°C with varying PL (1000-4000 mg P/kg) and incubation times (14-90 days).
• Wetting and drying cycles using DW and AW, monitoring available-P, soluble-P, Ca²⁺, Mg²⁺, and soil pH.

Main Results:

• Phosphorus availability and solubility increased significantly with higher PL and longer incubation times.
• Acidified water (AW) was more effective than distilled water (DW) in enhancing P release and related parameters while reducing soil pH.
• Bone ash (BA) showed optimal performance for available and soluble P compared to bone char (BC) and phosphate rock (PR), especially with AW application.

Conclusions:

• Acidified water (AW), simulating rhizosphere acidification, significantly optimizes P release from BA and BC in calcareous soils.
• Bone ash (BA) and bone char (BC) act as effective, eco-friendly phosphate fertilizers, improving soil fertility and sustainability.
• Further research is needed for large-scale agricultural applications of these findings.