Cotton in Benin: microalgae, a green option to restore soils and improve yields

Benin could leverage microalgal biotechnology to make its cotton production more sustainable. This perspective was presented on July 14, 2026, during a webinar with Beninese journalists and researchers from Mohammed VI Polytechnic University in Morocco.

Professor Hicham El Harroussi discussed the agricultural applications developed from these microscopic organisms, which can transform carbon dioxide into biomass using light. The research conducted by UM6P has led to the development of biostimulants, biofertilizers, and biocontrol products aimed at improving crop growth and resilience.

These solutions are particularly relevant for the Beninese cotton sector, which is facing gradual soil depletion, variable rainfall, water stress, and input costs. Products derived from microalgae could be used alongside conventional fertilizers to improve their effectiveness and gradually restore the biological activity of cultivated lands.

Yield Gains Observed in Morocco

Biostimulants do not directly provide the main nutrients to plants. Instead, they activate their natural mechanisms, improve nutrient absorption, and enhance their ability to withstand drought, salinity, and certain diseases.

Biofertilizers, on the other hand, are made from species of microalgae that are rich in nitrogen, phosphorus, potassium, and other beneficial elements for crops. They can help improve soil fertility, while biocontrol products aim to reduce the use of chemical pesticides.

According to the results presented by UM6P, experiments conducted in Morocco achieved yield increases ranging from 15% to 30%, depending on the crops and production conditions. Researchers also report favorable effects on the recovery of degraded lands.

However, these performances cannot be automatically applied to Beninese cotton. The cultivated varieties, soil composition, rainfall patterns, and agricultural practices vary from one region to another. Local agronomic trials would therefore be necessary to measure the effectiveness of the formulations, determine appropriate doses, and assess the costs for producers.

The interest in this technology arises as Benin seeks to revitalise its cotton production. For the 2026-2027 agricultural campaign, authorities have set a target of at least 700,000 tonnes of cottonseed, representing an expected 20% increase. This ambition relies on access to inputs, high-performing seeds, mechanization, water management, and strengthening agricultural advice.

Additionally, the government continues to provide financial support for inputs. For the current campaign, the state has maintained subsidized prices for fertilizers, herbicides, and insecticides, while setting a higher purchase price for organic cotton than for conventional cotton.

Microalgae-based solutions could fit into this strategy without an immediate phasing out of mineral fertilizers. Their role would primarily be to gradually reduce the necessary quantities, improve nutrient assimilation, and limit land degradation caused by certain intensive practices.

Microalgae also have the advantage of being cultivated in ponds or photobioreactors, sometimes using saline water and on non-agricultural land. Their production would therefore not necessarily compete with food crops for land use or freshwater resources.

Implementing this in Benin would still require cooperation between researchers at UM6P, Beninese agricultural research institutions, cotton sector structures, and producers. It would also necessitate product approval, safety evaluations, and the establishment of local manufacturing or supply capabilities.

Beyond cotton, researchers believe that biostimulants and biofertilizers derived from microalgae could be tested on maize, rice, soybeans, vegetable crops, and fruit trees.