Gentoo penguins, Pygoscelis papua, on the beach at Sea Lion Island in The Falkland Isles

Swallow-tailed seagull and Marine iguana perched on rocks, Galapagos Islands, Ecuador

Swallow-tailed gull perched rocks, Galapagos Islands, Ecuador

Phosphate works for processing guano bird droppings in Nauru in the South Pacific

Guano bird droppings in Nauru in the South Pacific

Zambia tephrosia, natural insecticide, nitrogen-fixer

Goat cheese snow: chevre noir turned into snow by liquid nitrogen, basil oil, eatable menu, Restaurant Moto, Chicago, Illinois, USA

Back River sewage treatment plant, Baltimore, MD

Agriculture

Research assistant working on nitrogen exchanges between bacteria and the roots of legumes in the tropical forest of the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old researcher and her team working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old researcher working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Research assistant working on nitrogen exchanges between bacteria and the roots of legumes in the tropical forest of the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Earth diluted with water in order to extract the PH from the soil as part of a study on nitrogen exchanges between bacteria and the roots of legumes in the tropical forest of the "La Selva" research station in Puerto Viejo from Sarapiqui, Costa Rica

27-year-old researcher working in a lab on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Earth diluted with water in order to extract the PH from the soil as part of a study on nitrogen exchanges between bacteria and the roots of legumes in the tropical forest of the "La Selva" research station in Puerto Viejo from Sarapiqui, Costa Rica

27-year-old researcher working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old researcher and her team working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old researcher working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old researcher working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old female researcher working on nitrogen exchange between bacteria and the roots of legumes showing an example of a nodule of bacteria attached to the roots in the rainforest of the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

27-year-old researcher working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

29-year-old assistant researcher working on nitrogen exchange between bacteria and the roots of legumes in the rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica