Fertilizers and nitrate pollution of surface and ground water: an increasingly pervasive global problem

TLDR

We have content for each. Let's aggregate. Something like: "Nitrate pollution of surface and groundwater worldwide is linked to rising global fertilizer nitrogen use, especially in developing countries, making it an increasingly pervasive problem." That covers both. Purpose: The sentence labeled [Purpose, Mechanism] says: "In this review it has been attempted to review the research information generated during the last two decades from all over the world on different aspects of nitrate pollution of natural water bodies." So purpose: "This review surveys global research from the past two decades on various aspects of nitrate pollution in natural water bodies." That is concise. Mechanism: There are multiple mechanism sentences: the one with [Purpose, Mechanism] also counts as mechanism?

Abstract

Abstract Nitrate pollution of ground and surface water bodies all over the world is generally linked with continually increasing global fertilizer nitrogen (N) use. But after 1990, with more fertilizer N consumption in developing countries especially in East and South Asia than in the industrialized nations in North America and Europe, nitrate pollution of freshwaters is now increasingly becoming a pervasive global problem. In this review it has been attempted to review the research information generated during the last two decades from all over the world on different aspects of nitrate pollution of natural water bodies. It is now evident that not more than 50% of the fertilizer N is directly used by the crops to which it is applied. While a small portion may directly leach down and may reach ground and surface water bodies, a large proportion ends up in the soil organic N pool from where N is mineralized and is taken up by plants and/or lost via leaching during several decades. Present trends of nitrate pollution of freshwaters, therefore, reflect legacies of current and past applications of fertilizers and manures. Tools such as simulation models and the natural variation in the stable isotopes of N and oxygen are now being extensively used to study the contribution of fertilizers and other sources to nitrate enrichment of freshwaters. Impacts of agricultural stewardship measures are being assessed and nitrate enrichment of water bodies is being managed using modern digital models and frameworks. Improved water and fertilizer management in agroecosystems can reduce the contribution of fertilizers to nitrate pollution of water bodies but a host of factors determine the magnitude. Future research needs are also considered.