Organic biofertilization protocols for coffee agroecosystems using native mycorrhizal fungi and organic amendments

Overview

This research program develops and evaluates organic fertilization protocols for coffee agroecosystems, combining native arbuscular mycorrhizal fungi (biofertilizer inoculum) with organic amendments such as compost, liquid earthworm humus, and biol. The work addresses the need for sustainable soil management by leveraging beneficial soil microorganisms and recycling organic residues from agricultural and livestock activities. The goal is to identify which fertilization protocol best enhances soil microbiological activity, richness, and abundance, while also improving coffee plant growth and development.

The approach offers an environmentally responsible alternative to conventional fertilization, delivering benefits to soil health, worker safety, and local economies. It is particularly relevant for organic coffee production systems in Venezuela and similar tropical regions.

Technical specifications

Biofertilizer (mycorrhizal inoculum):

• Prepared from native arbuscular mycorrhizal fungi isolated from coffee rhizospheres
• Six Glomeromycota fungi morphotypes identified from the La Cabellera sector
• Tested on coffee plants with positive preliminary results

Organic fertilizers developed:

• Compost based on coffee husks and horse manure
• Liquid earthworm humus based on coffee husks and horse manure
• Biol based on cattle manure, milk, and phosphate rock

Soil microbiological indicators evaluated:

• Number of spores and adult nematodes
• Mycorrhizal colonization values
• Biodiversity indices of indicator microorganisms

Physical and chemical soil analyses:

• Texture and apparent density
• Macronutrients, pH, and electrical conductivity

Technology readiness level

The research is at an early-to-mid stage of development. Initial laboratory and nursery work (2020–2021) has confirmed significant differences in spore counts and nematode populations across studied coffee lots, and the mycorrhizal inoculum has been successfully tested on coffee plants. Organic fertilizers have been prepared and characterized. Ongoing fieldwork (2020–2022) involves nursery planting, field transplanting, and comprehensive laboratory analyses of soil and plant responses. The program is expected to produce five scientific publications covering inoculum preparation, fertilizer characterization, and the effects of fertilizers on soil and coffee plants. The protocols are ready for further field-scale validation and potential adaptation to commercial organic coffee production systems.