Balanced and precise crop nutrient application - of organic as well as mineral fertilizers - is a prerequisite relevant tool for meeting the second Sustainable Development Goal to end hunger, achieve food security, improved nutrition and promote sustainable agriculture. It is also a crucial building block of climate-smart agriculture. Soil-and crop-specific plant nutrition increases agri cultural productivity with a view towards providing food security for an expected global population of about 10 billion people by 2050, but also ensures a maximum uptake of nutrients by plants and a concomitant de-crease of nutrient losses to the environment, including emissions of nitrous oxide. By sustainably increasing productivity on arable land, efficient and effective fertilization also safeguards the world’s forests and help maintain or increase soil organic matter, two enormous carbon sinks. Last but not least, as one of the effects of climate change in the long run will be an increase of temperature and water stress, proper crop nutrition will help build resilience in agricultural crops, a prerequisite for climate change adaptation.The world’s farmers are on the frontline of the tremendous challenges facing the agricultural sector. With the unfortunate decline in extension services seen in many parts of the world, greater efforts to transfer knowledge on best management practices in the area of plant nutrition are required. Towards this end, WFO, IFA and GACSA are delighted to release this handbook, which is intended to outline the key principles of precise and balanced crop nutrition, to assist farmers in their invaluable work of feeding the growing global population, while improving and safeguarding soil health in a changing climate. Building on the premises of climate-smart agriculture and the principles of integrated soil fertility management, which call for combining organic and mineral nutrient sources with appropriate soil management practices and crop variety selection, and on the “4Rs” of nutrient stewardship, namely the need to determine - based on crop-and soil-specific investigation - the 1) correct source of fertilizers (matching the fertilizer types with the crop needs); 2) the right rate (matching the amount of fertilizer with the crop requirements); 3) the right time (making nutrients available according to the crop production cycle); and 4) the right place (placing the nutrients where crops can best access them), this handbook provides useful and practical information intended to facilitate efficient and efective crop nutrition by agricultural practitioners. This Nutrient Management Handbook provides farmers and farmers’ organizations with useful and straightforward practical information on the combination of fertilizers and their effects on plant growth and on soils, including guidelines on efficient nutrient management techniques, which should be tailored to the specificities of particular crops, soils and climatic conditions.This joint effort by WFO, IFA and GACSA is a good example of a multi-stake-holder partnership to promote Sustainable Development Goal 2 and cli-mate-smart agriculture, and our three organizations are committed to disseminating its recommendations to farm groups around the world.