The global nitrogen cycle in the twenty-first century.

The global nitrogen cycle in the twenty-first century: introduction.

Nitrogen use efficiency and life cycle of nodules in alfalfa after different mineral fertilization and soil cultivation

Nitrogen use efficiency and life cycle of root nodules in alfalfa after different mineral fertilization and soil cultivation practices were studied. Field trial was conducted in the Institute of Forage Crops, Pleven, Bulgaria on leached chernozem subsoil type and no irrigation. The next treatments were tested: i) for fertilization as follows: N0P0K0 (control); N60P100K80 (an accepted technology...

A chronology of human understanding of the nitrogen cycle.

Nitrogen over the ages! It was discovered in the eighteenth century. The following century, its importance in agriculture was documented and the basic components of its cycle were elucidated. In the twentieth century, a process to provide an inexhaustible supply of reactive N (Nr; all N species except N2) for agricultural, industrial and military uses was invented. This discovery and the extens...

N2O emissions from the global agricultural nitrogen cycle – current state and future scenarios

Reactive nitrogen (Nr) is not only an important nutrient for plant growth, thereby safeguarding human alimentation, but it also heavily disturbs natural systems. To mitigate air, land, aquatic, and atmospheric pollution caused by the excessive availability of Nr, it is crucial to understand the long-term development of the global agricultural Nr cycle. For our analysis, we combine a material fl...

Investigation on life cycle assessment of lead and zinc production

Lead and zinc production is one of the main predisposing factors of excessive greenhouse gases emissions, air pollution and water consumption. In this paper, the environmental problems of lead and zinc production in Calcimin plant are expressed and life cycle assessment of this plant is assessed. The data regarding the amount of induced global warming and pollution, acidification, and depletion...

Globalization Discourse, Justice, and Development Programs in the Islamic Republic of Iran

Globalization is one of the most important developments of the late twentieth century, which is continued intensively in the twenty first century. Due to the complexity and multifaceted terms of the subject matter and level of analysis, there has been multiple and even contradictory definition for it. One of the most significant debates in the field of globalization is whether globalization lea...