『Abstract
　Capabilities of two phosphate-rich organic wastes to quench phosphorus (P) fixation in a stored high-phosphorus-fixing tropical bauxite overburden were examined in a field experiment. Prior grinding and ensiling of shrimp shell waste facilitated increased solubility and hence phosphorus fixation quenching in the soil. Normal plant-available P concentrations were exhibited by the overburden for up to 4 months after application despite the cultivation and harvesting of plants in the treated beds. Ten-year-old, stored overburden treated with ensiled shrimp shell silage, or chicken manure exhibited P levels of 1.0 and 1.1％, respectively, 4 months after treatment application. This represents a small excess over normal concentrations of free P in the overburden. These P levels dropped to 0.055 and 0.060％, respectively, after 8 months. The capacity of the soil to fix phosphorus was thus rapidly “filled” with an excess of P in the overburden. However, increased P fixation in the second 4-month period was attributed to the inherently high levels of Ca²⁺ in the ground. Therefore, amelioration based on quarterly applications promises a long-term corrective for P-fixing in stored bauxite overburdens.

Keywords: Bauxite overburdens; Phosphate fixation; Phosphorus; Shrimp shell waste』

Introduction
　Source of added phosphorus
Materials and methods
　Neutralization of the shrimp silage
　Test plant
　Study area: a former mine-site
　Measurements
　Land preparation
Results
　Plant heights
Discussion
Conclusion
Recommendations
References