Smil,V.(2002): Phosphorus: Global transfers. Douglas,I. ed. Volume 3, Causes and consequences of global environmental changes, 536-542. Munn,T. Editor-in-Chief, Encyclopedia of Global Environmental Change, John Wiley & Sons, Ltd, Chichester.


 Although relatively rare in the biosphere, phosphorus (P) plays several key roles in the chemistry of life, above all due to its presence in nucleic acids (deoxyribonucleic acid, DNA and ribonucleic acid, RNA) and in adenosine triphosphate, the life's carrier of energy. Phosphorus - unlike carbon, C, nitrogen, N and sulfur, S - does not form any long-lived atmospheric compounds and hence its global cycle is just a part of the grand, and slow, process of denudation and geotectonic uplift. But on a small scale the element is rapidly recycled between organic and inorganic forms in soils and water bodies. Human activities now annually move more than four times as much phosphorus as did the natural processes during the preagricultural era.
 Together with nitrogen and potassium, phosphorus is one of the three macronutrients needed by all plants, and its applications in inorganic fertilizers have been essential for raising crop yields during the 20th century. The nutrient is also frequently the limiting factor of aquatic productivity, and even its relatively low concentrations present in the runoff from fertilized fields can cause eutrophication (excessive nutritional enrichment) of both fresh and ocean waters, an environmental change with numerous undesirable consequences. Fortunately, appropriate agronomic practices and wastewater treatment can moderate the environmental impact of anthropogenic phosphorus.』

Importance of the element
Natural sores and flows of phosphorus
Anthropogenic mobilization of phosphorus
Dependence on inorganic fertilizers
Phosphorus in agricultural soils
Phosphorus in waters
Moderating the human impact

Figure 1 Global phosphorus cycle

〔Smil,V.(2002)によるPhosphorus: Global transfersから〕

表1 リンの主要な生物圏のリザーバとフラックス
リンのリザーバ 全量(100万トンP)
海洋 93000
 表層 8000
 深層 85000
土壌 40-50
 無機リン 35-40
 有機リン 5-10
植物体 570-625
 陸上 500-550
 海洋 70-75
動物体 30-50
人間体 3
リンのフラックス 年間速度
大気沈着 3-4
浸食と流出 25-30
粒状リン 18-22
溶存リン 2-3
植物摂取 970-1300
 陸上 70-100
 海洋 900-1200
海洋堆積物中への埋没 20-35
構造的隆起 15-25

表2 世界的なリン循環の人為による増加分
フラックス 天然 産業化以前
浸食 >10 >15 >30
<2 <3 >3
>8 >12 >27
河川運搬 >7 >9 >22
粒子状リン >6 >8 >20
溶存リン >1 <2 >2
生物体燃焼 <0.1 <0.2 <0.3
農作物摂取 - 1 12
動物排泄物 - >1 >15
人間排泄物 - 0.5 3
有機リサイクリング - <0.5 >6
無機肥料 - - 15