Human activities, in particular agricultural production, interfere with natural cycles of nutrient elements, nitrogen (N) and phosphorus (P), leading to growing concerns about water quality degradation related to excessive nutrient loadings. Increases in agricultural production in response to population growth and wealth generation further increase risks associated with nutrient pollution. This paper presents results from projections of nutrient exports from global agricultural crop and pasture systems to the water environment generated using a process-based modeling approach.

Dryland regions in Sub-Saharan Africa are home to one-half of the region’s population and three-quarters of its poor. Poor both in natural resources and in assets and income, the inhabitants of drylands are highly vulnerable to droughts and other shocks.

Due to its arid to semi-arid climate, water is the single most constraining factor to Pakistani agriculture. Water resources are heavily appropriated for productive uses, and agriculture is the main user of water resources. Over eighty percent of crop value comes from irrigated agriculture.