Energy management in agriculture will be of current interest in the near future. Modern agriculture is run by fossil energy and it is unclear how this energy input will be replaced with renewable energy. The year 2008 gave some foretaste how rapidly and how much energy price can rise. Energy saving and exploiting farm’s own energy resources are ways to reduce dependency on oil. Nitrogen fertilizer is the most significant energy input in plant production because ammonia manufacturing is very energy intensive. Crop rotations including legumes, green fertilization, and better manure management are measures to replace synthetic nitrogen. Traditional work chains can be replaced with more energy efficient operations. Direct drilling and grain preservation methods other than drying are good examples. Animal housing requirements for inside temperature and air quality define the demand for heating and ventilation. Along with milking and milk cooling, they are the most significant energy inputs in animal production. Animal welfare has to be respected always; however, by means of heat recovery and biogas production it is possible to save energy and exploit energy from manure. Energy should not be considered as a separate question; on the contrary, a farm has to be considered as a whole and as a part of the rest of the society. Better energy management and plant nutrient recycling are combined issues and require more comprehensive approach than it has been the case.