SINCLAIR STAMMERS / Light photomicrograph of Blue green algae / Cyanobacteria (Nostoc sp) capable of nitrogen fixation, and used for soil enrichment especially with rice cultivation. The long filaments are composed of in...

Nigel Cattlin / Broad bean (Vicia faba) roots with root nodules formed by Bacteria (Rhizobium sp) for nitrogen fixation.

David Woodfall / Nitrogen fertilzer in bags, ready for application to machair, coastal grazing habitat. Outer Hebrides. Scotland, UK, June.

Willem Kolvoort / Norilsk, a large industrial town above the Arctic Circle, produces Nickle, Palladium, Copper, Cobalt etc and is the largest stationary source of air pollution in Russia. Gases including sulfur diox...

Willem Kolvoort / Norilsk, a large industrial town above the Arctic Circle produces Nickle, Palladium, Copper, Cobalt etc. and is the largest stationary source of air pollution in Russia. Gases including sulfur dioxide...

Willem Kolvoort / Polluted land with dead trees near Norilsk, a large industrial town above the Arctic Circle which produces Nickle, Palladium, Copper, Cobalt etc. and is the largest stationary source of air pollution...

Willem Kolvoort / Norilsk, a large industrial town above the Arctic Circle produces Nickle, Palladium, Copper, Cobalt etc. and is the largest stationary source of air pollution in Russia. Gases including sulfur dioxide...

Christophe Courteau / Aerial view of Saint-Michel-en-Grve beach. The green color of water is due to algae (Ulva armoricana) growth caused by nitrogen pollution from agriculture. Cotes d'Armor, Brittany, France, September 2...

Chien Lee / Rainforest Orchid (Bulbophyllum beccarii) with leaves designed to trap falling nitrogen-rich leaf litter, the flowers smell like rotting fish which attracts swarms of pollinator flies, Mulu National P...

Chien Lee / Mountain Tree Shrew (Tupaia montana) feeding on Pitcher Plant (Nepenthes rajah) nectar, inevitably leaving its scat in the pitcher which is a valuable nitrogen source in their impoverished mountain ha...

Chien Lee / Low's Pitcher Plant (Nepenthes lowii) derives nitrogen nutrients from droppings of Mountain Tree Shrew (Tupaia montana) which are attracted to the nectar secretions, inevitably leaving their scat in t...

Chien Lee / Low's Pitcher Plant (Nepenthes lowii) derives nitrogen nutrients from droppings of Mountain Tree Shrew (Tupaia montana) which are attracted to the nectar secretions, inevitably leaving their scat in t...

Adrian Davies / Nitrogen fixing nodules on roots of leguminous plant, caused by Bacterium {Rhizobium sp} UK

Nigel Cattlin / Common vetch (Vicia sativa) with magenta flowers flowering in rough grassland, Berkshire, May

Nigel Cattlin / Common vetch (Vicia sativa) with magenta flowers flowering in rough grassland, Berkshire, England, UK. May

Nigel Cattlin / Nitrogen fixation nodules on roots of Lupin (Lupinus sp.) plant, effective in the fixation of gaseous nitogen with symbiotic rhizobium bacteria, Berkshire, UK. July.

Will Watson / Alder (Alnus glutinosa) root nodule containing nitrogen-fixing bacterium, close up, Herefordshire, England, UK. Focus stacked.

Nigel Cattlin / Common vetch (Vicia sativa) flowering nitrogen fixing leguminous plant grown for fodder, Champagne, France

Nigel Cattlin / Experimental plots of Triticale (var. salvo) showing normal fertilizer application nitrogen (left) compared with no nitrogen which is shorter, weaker and yellower (right)

Nigel Cattlin / Flowering white clover, Trifolium repens, pasture and forage crop for nitrogen fixation in grassland, Berkshire, July

Nigel Cattlin / A crop of Field or Fava beans (Vicia faba) flowering. Used for animal food and as a break crop to replace soil nitrogen levels

Nigel Cattlin / Dark veins and yellow interveinal chlorosis, a symptoms of iron deficiency on ornamental garden rose leaves, Berkshire, England, UK, August

Nigel Cattlin / Red clover (Trifolium pratense) flower.

Nigel Cattlin / Red clover (Trifolium pratense) flower.