Introduction
The history of agriculture starts at least 22,000 years ago when mankind learned to collect wild grains as food. Various crops have been cultivated as earlier as 9500 BC in Levant according to archaeological discoveries (Hillman, 1996; Walsh, 2009). Over tens of thousands of years since then, significant innovations have been made from time to time to increase the agricultural yield and reduce the heavy human labor needed. However, the demand for more foods from the increasing population will never get satisfied. It is predicted that the world’s population will reach 9.7 billion by 2050, which is about 33% more than today (un.org, 2015). Consequently, to keep pace with such population growth, the global production of food has to increase at least 70% to feed the world. Meanwhile, only a small portion of earth’s surface is available for agriculture uses, due to various limitations, including temperature, climate, topography, soil quality, and technologies. Agricultural land use is also shaped by political and economic factors, such as land tenure patterns, environmental regulations, and population density (learner.org, 2016). In fact, the total agricultural land used to produce food has been decreasing for the last few decades. In 2013, total agricultural land used to produce food was around 18.6 million square miles, which covers 37.73% of the world’s land area. In comparison, in 1991, these numbers were 19.5 million and 39.47%. So, humanity is facing a daunting challenge of how to feed more people with less land, as shown in Figures 18.1 and 18.2 (WorldBank, 2016).
