ABSTRACT
Agriculture, including associated primary industry such as production of machinery, fertilizers, feed concentrates for livestock, agrochemicals, water and agroprocessing, is an energy intensive activity. To manage the escalating global food demand, agriculture is increasingly becoming energy intensive, and importantly, the agricultural frontiers are expanding into areas that are not ideally suited for farming. This further translates to an increase in demand for energy, which is not proportional to the food production increase achieved. In many cases, energy cost may represent up to 20-50% of the total agricultural production inputs cost, including the cost of manufacturing and transportating inputs such as fertilizers. Nutrient-poor soils not only require large quantities of fertilizers but may also require large volumes of irrigation water, which, in some instances, must be pumped from ever-greater depths. The last is caused by increasing limitations on the availability of surface water due to seasonal fluctuations and its continuous quality degradation as a result of anthropogenic contamination, which in many areas makes groundwater the principal source for irrigation and other agricultural purposes. The importance of groundwater for agriculture will undoubtedly further increase in the future with the need to sustain food supplies to an increasing world population. Thermal desalination of seawater or saline or brackish groundwater, which in many areas will be the only available option for regional or national food production, is even more energy demanding.
