Energy and Economics.

A common theme of agriculture has been continual change resulting from new technologies and economic conditions. Energy inputs have been an evolving process from human and animal energy to fossil fuel and other forms of energy. Current cropping systems in the Northern Great Plains of North America are reliant on energy inputs to maintain current crop yields. The main energy inputs are embodied in fertilizer, fuel (plus oil and lube), machinery, pesticides, and general farm overhead. Nitrogen fertilizer is the primary energy input, and with current profitability of crop production the use of nitrogen has increased in recent years. Crops grown will determine the fertilizer requirement, cereal and canola oilseed crops require high levels of nitrogen for profitable crop production but annual legumes such as pea, lentil and soybean require little of no nitrogen fertilizer. The higher energy input crops are grown because they are profitable. In recent years there has been increased pulse cropping, some due to rotation consideration and some due to profitability of pulse crops. The intensity of tillage will impact fuel and machinery energy inputs, and to a lesser extent pesticide energy inputs. The adoption of no-till has reduced fuel and machinery energy inputs, but increased pesticide energy. No-till systems dominate much of the northern Plains because it is profitable and equipment is better designed for no-till. Fossil fuel energy will continue to be an essential input for profitable cropping systems.