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Land clearing and increased use of agrochemicals make agriculture one of the largest drivers of global climate change. The doubling of cereal production during the past 50 years has reduced hunger and malnutrition worldwide, but much of this increase was attained by the use of new crop varieties and greater inputs of fertilizer, water, and pesticides. Over the next 50 years, the global population may reach 9 billion, and require a further doubling of food production. Increasing agricultural production while maintaining environmental quality is one of humanity's grand challenges. I present two case studies from the tropics (Latin America and East Africa) where sustainable agricultural strategies can optimize tradeoffs between intensifying crop production and environmental impacts. In Costa Rica, I investigated the balance between nitrogen losses, carbon storage, and yields in shade coffee farms. I found that (1) agroforests capture a similar proportion of added nitrogen regardless of whether it comes from a mineral or organic source, and (2) nitrogen losses decrease significantly with increasing tree biomass with minimal consequences for yield. In sub-Saharan Africa, a region poised to increase fertilizer application 6-fold in the coming years, I investigated the tradeoffs between maize yields and nitrogen losses in response to increasing fertilizer levels. I found that the current “one-size-fits-all” approach to fertilizer management will have considerable environmental and human health consequences and recommendations must be tailored to a region’s climate and soil type.