Agriculture in the North Western Sahara Aquifer System: A miracle in the making?

Abstract

T he Sahara Desert, a vast, seemingly empty land mass covered with sand or sand dunes with sparse, if any, scrub vegetation, covers an area of 9.4 × 106 km2 (3.63 × 106 mi2) (Abotalib et al. 2016). Sahara is a feminine name based on an Arabic word sahrā or “desert.” It extends from Atlantic Ocean in the west to the Red Sea Hills in the east, and from Mediterranean Sea in the north to the Sahel Zone in the south. Because of the arid climate, average annual precipitation of less than 5 mm (0.2 in) (New et al. 2000), and harsh environments, agriculture traditionally has been confined to specific areas called oases (small patches of vegetation fed by a spring and surrounded by desert). Thus, the African continent, where the Sahara Desert is located, is characterized by the familiar bleak statistics, such as 300 million people without access to safe drinking water and only 5% of arable land being irrigated (Tornhill 2012). Furthermore, prevalence of undernourishment in Africa (the percentage of the total population prone to lack of access to safe and healthy food) has been on the rise and was 44.4% in 2014, 49.7% in 2016, 51.3% in 2018, 52.4% in 2019, and 56.0% in 2020. Of this, prevalence of severe undernourishment (percentage of total population) was 16.7% in 2014, 19.2% in 2016, 19.3% in 2018, 31.9% in 2019, 32.2% in 2020, and 34.4% in 2021 (FAO et al. 2022).The problem of food insecurity is presumably aggravated by the current and projected increase in population, especially that of sub-Saharan Africa. The populations of Europe and North America combined (1.18 billion) and that of sub-Saharan Africa (1.2 billion) were similar in 2022. However, the rate of increase in population has been less than 1% in Europe and North America since the 1960s and is reaching the level of zero growth in 2020 and Rattan Lal is a distinguished university professor of soil science and is director of the CFAES Rattan Lal Center for Carbon Management and Sequestration, The Ohio State University, Columbus, Ohio. Received January 6, 2023. 2021 (UN 2022). In comparison, the annual rate of population growth in subSaharan Africa peaked at 3% in 1978 and remained above 2.8% in the 1980s; it is now the region with the fastest growing population, which is projected to double by 2040 (UN 2022). Similar to the historic concerns about South Asia and China, there are many discouraging questions: Who will feed Africa? Can Africa feed itself? Are there enough natural resources to feed the growing population?” In the final analysis, it is Africa that will feed its population, and it has natural resources to do so (Muang and Andrews 2014). Instead, it is a question of when its policy makers will create environments (pro-nature, pro-farmers, pro-agriculture, and pro-innovations) that translate known science into action (World Bank 2012). It is precisely in this context that recent agricultural progress in the Sahara is an important indication that Africa has an abundance of water (even under the Sahara), and indeed, can be the future breadbasket of the world. The objective of this article is to describe some recent advances in promoting intensive agriculture in the Sahara Desert based on water conservation and management (drip fertigation) from the shallow aquifer beneath the sand.