The Spanish city of Valencia will resort to sheep to contain the growth of weeds and brush in ravines, dry riverbeds and developed areas with excessive vegetation. Announced by city councilor Consol Castillo, the measure falls within a new kind of urban agriculture that’s being encouraged by the United Nations’ Food and Agriculture Organization (FAO).

The use of grazing animals as “biological lawnmowers” is not a new concept. Following a wave of wildfires in Portugal last year, the government of that country has decided to use goats to eliminate undesirable vegetation in unkempt fields. Sheep have been spotted performing a similar task near Charles de Gaulle airport in Paris. And two years ago, a goatherd was hired by the city of New York to bring in his animals and clear Prospect Park, which is twice the size of Madrid’s El Retiro. Weed grazing is widely considered an environmentally friendly and sustainable alternative to chemical pesticides and mechanical lawnmowers.

For cities and residential communities, livestock has an important role to play in biomass control

Valencia Councilor Consol Castillo

In Valencia, there are only two herds of sheep left of a species native to the area. The endangered Guirras have reddish skin and wool, and one of the herds is the property of the Polytechnic University of Valencia, where the animals live.

“The truth is, there is only one active herd left, since three other herds of sheep and goats have disappeared over the last decade, and everything suggests that it is due to excessive urban development pressure,” says Councilor Castillo, who heads the agricultural affairs department. Since 2015, the city has been run by a leftist coalition led by the regional party Compromís.

Now, city authorities and the agricultural organization Unió de Llauradors i Ramaders have reached a deal to encourage more livestock activity in Valencia. Castillo says that by fomenting the use of grazing animals, “we are observing our own regulations about organic production, which say that there can be no herd without land, and also that there shouldn’t be cultivated land without a herd, since they close the organic matter circle and are additionally very energy-efficient.”

Besides clearing forest land of undesired plant species, the grazing animals could also eat the organic matter that is left over after harvesting, thus avoiding the traditional but environmentally damaging system of burning waste that is widely practiced by farmers in the area. And farmers could also benefit from the manure produced by the herds.

Areas that are being targeted for weed grazing include the ravines located near small population centers and the new riverbed of the Turia, which is normally dry and filled with weeds.

“Without sheep, the land is soon overrun with shrubs and it loses biodiversity,” says Castillo. “It also increases the risk and intensity of wildfires,and reduces the availability of water in basins, especially in Mediterranean areas such as this one. That is why, for cities and residential communities, livestock has an important role to play in biomass control.”

Bringing back livestock production to Valencia, says Castillo, would also lead to “job creation in related occupations at slaughterhouses, butcher shops, distribution centers and cottage industries devoted to making wool, cheese-making and other milk products.”