20 agriculture: Africa On the Fringes of the Sahara: Northern and Western Africa The agricultural history of northern and western Africa does not follow the same chronology as that of the equatorial forest or eastern and southern Africa The spread of iron technology, for example, did not occur in conjunction with the development of new farming practices but was adopted into early cultivation practices as an extension of an existing agricultural system Furthermore, nomadic pastoralism flourished along the dry fringes of the Sahara; interactions between savanna farmers and nomadic pastoralists of the desert fringes characterized social life and political organization for millennia On the northern coasts farming shared the characteristics and history of other Mediterranean agricultural systems in which farmers grew wheat, grapes, olives, and sometimes barley Like farmers in eastern and southern Africa, those in northern and western Africa grew sorghums, millets, and other grains in the savannas to the south and north of the desert, often using a system of shifting cultivation However, Africans living in the western region could also cultivate an indigenous rice, Oryza glaberrima, using one of three systems: In Guinea, for example, farmers planted rice on hillsides so that rainfall would irrigate the plants; along the Atlantic coast, farmers planted rice in mangrove swamps to ensure adequate moisture; rice planted in floodplains of the Senegal and Niger rivers was watered by floods and the moisture retained in the clay soils The hundreds of varieties of rice developed by West African farmers was an important factor in the development of early permanent farming settlements and in adaptation to the particular threats associated with each of the three rice cultivation systems Changes in relations between sedentary farmers and nomadic pastoralists characterize the period corresponding to the European Middle Ages By the fourth century c.e several important technologies had spread into northern and western Africa and transformed the mobility of nomadic pastoralists: cavalry, camels, and chariots With these new technologies, nomadic pastoralists were able to reconfigure earlier economic transactions in which farmers traded surplus grains, cloth, tools, and other products of sedentary life for pastoralists’ surplus meat and milk In earlier times farmers had controlled relations because pastoralists, as specialist producers had more need of farmers’ products than vice versa With the advent of technologies improving the mobility of pastoralists, relations became more balanced and developed into a pattern of alternating pastoralist and sedentary dominance over marginal lands between the steppe and the cultivated savanna As early as the 14th century the famous Tunisian historian Ibn Khaldun (1332–1406) interpreted the history of the ninth through the 14th centuries as the alternation of power between sedentary farmers and nomadic pastoralists, with the latter often raiding and conquering the former Nomadic dynasties ruling over sedentary farmers were, of course, prey to raiding and conquest by other nomadic pastoralists on the savanna fringes This pattern continued long past the 14th century and is a common theme tying western and northern African history to historical patterns in Eurasia and beyond Among the most important historical themes in precolonial West African history is the development of a series of states on the southern edge of the Sahara The first of these states appeared at the turn of the first millennium c.e., and they continued to emerge, one succeeding the next, into the middle of the second millennium c.e Generally, the development of the West African states of Ghana, Mali, Kanem, Borno, and the Songhai Empire was tied to control of transSaharan trade, particularly the supply of gold from the south to the trade networks spanning the desert However, the agricultural productivity of these trade empires was central to their survival Although loss of trade monopolies meant loss of regional predominance, droughts and other agricultural catastrophes could mean the collapse of the state This was the case with the state of Ghana, which was located between the middle Senegal River and Niger River bend At the height of its power in the early 11th century, Ghana dominated the trans-Saharan gold trade By the middle of the 11th century, however, traders had found ways to access gold outside Ghana’s networks This shift marked the end of Ghana’s trade power but not its demise as a state It was only in the 13th and 14th centuries, when major climatic shifts threatened the farming lifestyle of its citizens and forced the dispersal of Soninke farmers from their homeland throughout western Africa, that the state of Ghana collapsed completely A similar pattern unfolded with the fall of the Axum state in Ethiopia, where trade was the heart of power but the breakdown of agriculture contributed to state disintegration in the eighth century These examples, coupled with those described for eastern and southern Africa, demonstrate the central role of agricultural activities in the history of state building in Africa and illustrate parallels with similar processes in Europe, the Middle East, and Asia Looking Forward Agricultural history in the period spanning the mid-first millennium c.e to the mid-second millennium c.e was characterized by elaborations on farming technologies that had spread during the ancient periods of African history Agricultural history in both the ancient and medieval periods in Africa reveals a slow series of developments in cultivation