Effect of olive-pomace based conditioners on soil aggregation stability: preliminary results from a micro-scale experiment

Abstract

The application of soil conditioners aims to reinforce aggregate stability (AS) and soil resistance to erosion. The wet olive pomace (OP), from olive oil production in two phases, can be used in composting and obtaining organic conditioners (OPC). The objective of this work is to present the results of an experiment carried out to evaluate the influence of OPC on AS. The experiment involved two soils of potentially different degrees of aggregation (1, silt loam; 2, clay loam), in which three OPC were applied, in three doses. Aggregate samples (1-2 mm) were mixed with conditioner (<0.75 mm), subjected to daily cycles of wetting and drying, and collected at 5 moments along the 30-day experimental period. AS was determined by shaking and wet sieving. The hypothesis that soil 2 has a significantly higher AS than soil 1 was confirmed. In this, the addition of conditioners significantly increased the proportion of stable aggregates as compared to the original soil, at all dosages, which was not observed in soil 2. The incorporation of OPC in soils cultivated with olive groves, contributing to the circular economy, improves soil protection by increasing stable aggregates.