Essay by leminhnhatUniversity, Bachelor'sA, June 2004

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Question: Phosphorus cycles extremely slowly through ecosystems due to the afct that the major reserviors of this nutrient are contained largely in rock and other substrates. As a consequence, this nutrient often limits primary production

Discuss this statement in term sof the global phosphorus cycle, and outline the general patterns of the cycle. What human activities are considered to impact upon the phosphorus cycle?



In the ecosystems, nutrients continuously cycle through living-organisms and non-living environments in such a way that all organisms can access nutrients to maintain their growth. Phosphorus is one of the most essential nutrients to organisms. Phosphorus has an extremely slow cycle due to the fact that large quantity of this nutrient is stored in sedimentary rocks for considerable period. As a result, this nutrient often limits the primary production. In order to improve crop production, humans have tried to increase the phosphorus concentration in soils by adding phosphorus-based fertilisers and manures to agricultural lands.

However, the excessive use of such fertilisers in agricultural lands and improper waste discharge into aquatic ecosystem lead to nutrient pollution in the

Importance of Phosphorus

Phosphorus is the essential element to fauna and flora in any ecosystem. Like nitrogen, it enhances major processes in plants such as photosynthesis, flowering, maturation, fruiting and seed production. In addition, phosphorus also stimulates root growth, strengthens structural tissues in straw or stalks and improves crop quality, especially in forages and vegetables (Brad& Weil 1999). Phosphorus is also the common element in structure of living organisms. According to Enger and Smith (1998), this element is present in many important biological molecules such as DNA and in membrane structure of cells. The bone and teeth of animals also contain significant quantities of phosphorus. Therefore, animals including human beings need to consume the phosphorus-contained food...