ABSTRACT
Table 3 gives the content of water, carbohydrates, fat, and protein [6] for several important foodstuffs, as well as their yields in tons per hectare and year.
The average harvest yields in 1999 are taken from the FAO yearbook [7]. However, it must be considered that these values have an enormous range both with regard to the year for these harvests and also the climate where the harvests were yielded. In Austria, the wheat productivity [9] between 1950 and 1999 grew from 2 to nearly 5 tons ha1 year1. But in 1999 in Europe, the differences [7] were still between 2.1 (Spain) and 7.3 tons ha1 year1 (Netherlands). However, more important is that high harvest results are only obtained by intensive fertilization and the use of herbicides. Through these methods, agricultural land and groundwater can be severely contaminated so that new agricultural policies in many parts of the world are required.
