Researchers develop project to improve the use of olive groves as a source of natural fertilizer

The University of Granada (UGR) is currently developing the AL-COMPOST project, an initiative that aims to optimize alperujo waste through composting, thereby obtaining a natural fertilizer while at the same time reducing operating times and improving the technical and economic viability of the process.

Within the context of conservation agriculture (CA), the composting of alperujo is a driver of decarbonization. For this reason, within the Andalusian olive sector, it is considered to play a strategic role in the circular economy recycling process involved in the production of top-quality organic fertilizer.

According to the researchers involved in the project, "One of the main problems in the olive sector is the challenge of developing sustainable systems to manage alperujo waste. For small and medium-sized olive mills, composting is a highly attractive option that facilitates the management of alperujo by-products and the production of compost, an organic soil conditioner that can contribute to conservation and decarbonized agriculture, with the ultimate aim of improving the quality and nutrient content of soils."

However, the alperujo composting process currently faces certain limitations. It takes a long time to complete, as this by-product contains recalcitrant compounds such as phenols and a high content of lignocellulosic fibers, which hinder its biological degradation.

To overcome these problems, the project proposes the use of two strategies. The first is the use of a treatment for phenol recovery, as phenolic compounds have strong antioxidant and antimicrobial properties, and their removal improves composting and enables the capture of phenolic compounds that have economic value.

The second is a bioaugmentation process through the addition of ligninolytic fungi. In order to meet these objectives and facilitate the transfer of the developed technology to the industrial sector, a demonstration-scale operation is currently being carried out as part of the project.

AL-COMPOST has several goals: to improve the competitiveness of traditional agriculture; to promote the sustainable management of natural resources and climate action; to achieve the balanced territorial development of rural economies and communities; to improve water and soil management in agriculture; to move towards a low-carbon economy; and to increase carbon sequestration in the agricultural and forestry sectors.

Provided by University of Granada