OPTIMIZATION OF NEUTRALIZING POWER OF Mytilus chilensis SEASHELLS IN ACID ALLUVIAL SOIL OF ÑUBLE COAST

Abstract

Seashells, residues from mussel (Mytilus chilensis), Hupé 1854 processing, are an environmental load on the coasts of southern Chile. The main component of this waste is calcium carbonate, which is commonly used to neutralize soil acidity. Its application in meadows is limited due to the large quantities (tons) required. The objectives of this work were to determine the most appropriate type of mussel seashells (M. chilensis) as a source of calcium carbonate (CaCO3) for pH neutralization of an alluvial acidic soil collected from Ñuble Coast, and to identify its optimal dose. The seashell doses were optimized using response surface methodology (RSM) to achieve a soil pH close to neutral and a relatively high neutralizing power, which was defined in comparison to the pH increase achieved with commercial CaCO3. Seashells with organic matter was the most suitable formulation for increasing soil pH with a high relative neutralizing power (94%), requiring a dose of 23% (w/w) to achieve soil pH values close to neutral. The fitted quadratic model explains 98.9% of variation inexperimental data. This work lays the foundations for future studies aimed to find new agricultural and/or livestock applications of wastes from the shellfish industry.

Liming Effect of Mussel Shell (<em>Mytilus galloprovincialis</em>) Waste on High Acidic Soil

“…According to the response surface analysis, at the end of the experiment (180 days) 64.6 g of Fine powder and 76.6 g Coarse powder mussel shells needed to neutralize pH on the acidic soil, respectively. In contrast, Leiva-Vega et al [26], who carried out an experiment using as liming material the mussel seashell Mytilus chilensis, succeeded to raise soil pH close to 7.0 using 190 g kg -1 , amount 84% and 68% higher compared to our results. Various studies have mentioned the positive impacts of seashells in soil pH increase [27][28][29].…”