A composting plant in San Luis Potosí has created a plague of flies for villages within its 30-kilometer radius. 

To create organic compost, chicken manure is left outside for exposure to the air and sun, but the process has attracted flies in the semi-arid San Luis Potosí desert, where egg producer Proan installed three poultry farms in the towns of Vanegas and Catorce, about 250 kilometers north of San Luis Potosí city. 

Proan sells the manure of millions of hens to the company Nuevas Tecnologías Agropecuarias (NTA), which gathers some 200 tonnes from the farms every day, and spreads the manure on a 20-hectare surface a few kilometers away to transform it into compost for sustainable farming. Local people said that one farm alone has some 6 million hens and 25,000 pigs. 

NTA produces 80 tonnes of compost a day, which goes to farmers in Michoacán, México state, Querétaro, Hidalgo and San Luis Potosí. The compost is significantly cheaper than its competing alternatives. 

Rancher Agustín Villanueva said the flies were making life miserable. “Instead of eating food, you are eating flies … you go out and you are batting away so many insects. Not to mention the smell,” he said.  

Villanueva’s daughter, Elpidia, said the affliction was affecting humans and animals alike. “It has been very ugly, very sad because there are many insects and it has been like three years that we have had the flies, battling and fighting them. It affects the animals … they are bitten, and they bleed where they are bitten,” she said. 

Local people are using a diluted toxic powder as a spray to deter the flies, but that is causing nausea, vomiting and headaches. 

However, one resident, who remained anonymous, said local people were not enemies of the companies involved. “We are not against the production, what we ask for is that they properly handle all the excrement,” he said.

NTA’s legal representative, René López Ruelas, said the company took responsibility. “It is clear to us that the people come first. That’s why we are here to offer an apology, and if it is necessary to leave, we will leave, but we have the municipal license that was granted to us, we have the lease,” he said.

He added that the lower price of its product was good for the market. “We are receiving about 200 tonnes of manure a day. We need the organic fertilizer … because chemical fertilizers, in addition to degrading the soils, … are too expensive.”

Proan promised to fumigate the affected communities and to improve its composting process. If they do not reach an agreement with those affected, they will abandon the project, the newspaper Milenio reported.

With reports from Milenio