Much of the recent gains in global crop production have been underpinned by greater use of fertilizer, especially nitrogen and phosphorus, and continued improvements in plant nutrition will be needed to meet the increasing demands for food and fiber from a growing world population. Climate change presents many challenges to improvements in nutrient use efficiency by its direct effects on the growth and yield of plants, and hence on nutrient demand, and by its influence on soil nutrient cycling, nutrient availability, and uptake. However, the consequences of climate change on plant nutrition are difficult to predict because of the complexity of the soil-plant-atmosphere system. Empirical data suggests that enhanced as well as reduced nutrient availability and uptake may occur as a result of climate change, depending on the nutrient in question and the component of the climate that changes. Notwithstanding the uncertainty of the effects of climate change on soil nutrient availability and plant nutrient uptake, improvements in nutrient use efficiency will be required to sustain productivity into the future.Over significant areas of the world's arable land, high inputs of nutrients have increased soil nutrient reserves and fertilizer use efficiency is low, while in other