The aim of the work is to establish the energy-efficiency of long-term experimental field "Sidrabini" at the Research Institute of Agriculture of Latvia University of Agriculture. The crop rotation of winter triticale, spring wheat, spring barley, spring oilseed rape and potato was tested on the influence of increasing fertilizer rates during 1994 - 2008. Four fertilizer doses were tested: NPK 0-0-0, NPK 45-30-45, NPK 90-60-90 and NPK 135-90-135. Energy-efficiency was calculated using methodology developed by the Moscow Timirjazev Russian State Agrarian University (MeTO..., 2007). Research results show that the spring rape used 32 GJ ha(-1), cereals consumed 30-35 GJ ha(-1) and potatoes- 66.5 GJ ha(-1) of energy, but the yields were obtained: 42 GJ ha(-1) from oilseed rape, 46-63 GJ ha(-1) by cereals and 119 GJ ha(-1) from potatoes. The energy efficiency ratio was 1.3 for spring rape, 1.5-1.8 for cereals and potatoes - 1.8. The highest energy efficiency was obtained by growing triticale and potato, but lowest- growing spring oilseed rape. Growing a crop without a fertilizer, energy expenditure was equal to the energy accumulated in the yield (energy efficiency ratio 1.0), but using fertilizers, regardless of the fertilizer rate, the energy efficiency ratio was 1.6.
