Early nineteenth-century British traveler Charles J. Cruttenden, like many who preceded and followed him, was amazed by the size and scale of Yemen’s agricultural terraces:
on leaving El hudein we ascended gradually for about two hours, when we reached the ridge of the mountains; and from the summit a most magnificent view burst upon us.
The hills formed an immense circle, like the crater of a huge
38 | Slavery, Agriculture, and Malaria in the Arabian Peninsula
volcano, and the sizes of which, from the top to the bottom, were cut regularly into terraces. We counted upwards of 150 in uninterrupted succession; and the tout-ensemble was most extraordinary.35
Yemen’s terraces had hardly changed one hundred years later, when Philby penned an even more appreciative description of Yemen’s magnifi-cent terraced landscape:
here nature and man have certainly combined to create a scene of astonishing beauty, and it seemed to me that man had actually outdone nature in their friendly rivalry. Imagine a great table-land thrust up to a height of 9000–9500 feet. . . . The surface of the plateau, plunging steeply down on one side in a series of splendid buttresses, slopes gently on the other in the curves of graceful valleys, forming huge theatres, for which man has provided the seats in terrace after terrace of cornfields.
In the middle of June the corn was ripe, and I shall never forget that scene of golden ears soughing and bowing under the gentle breeze, terrace after terrace, down the mighty flanks of those mountains, whose steeper slopes nature had reserved for her own planting a dense forest of junipers and other trees extending down to the 7500-foot level.36
The agricultural terraces of Yemen and elsewhere in the Arabian Pen-insula owe their origin to two contradictory characteristics of the Arabian landscape. Rainfall sufficient for dry farming falls, almost without excep-tion, only in the mountainous regions of the Arabian Peninsula. At the same time, the mountains themselves, which have thin soils and steep terrain, are in their natural state almost impossible to farm. Arabian agri-culturalists solved this problem through the construction of agricultural terraces, which captured and retained soil, trapped water, and provided a level surface for farming.
Building a terrace is extremely labor intensive. Farmers begin by dig-ging deep into the soil of a hill slope, in part to flatten out the slope of the land but also to excavate enough stone to build the necessary retaining walls. The next step is to build the retaining walls themselves, which follow along the contour of the hill, and which must be set deep enough into the soil to provide sufficient stability to the completed terrace. If the farmers
are able to save enough soil from the excavations, the bed of the terraces will be built using that soil; otherwise, soil might have to be brought in by the basketful from elsewhere, usually from alluvial deposits in the valleys below.37 In most cases, terraces were filled to slightly below the level of the retaining wall, since it was useful to retain a raised lip capable of impound-ing water and thus allowimpound-ing it to infiltrate the terrace soil. At the same time, the retaining wall could not be built too high, trapping an excess of water in one terrace, as this would both deny that water to lower terraces and create the danger of a collapse of the overfull terrace under the weight of the impounded water. to avoid both problems, some terraces were fit with overflows, reinforced by earth banks, to release excess water.38 Broad terraces on gently sloping land were generally planted with grains, and in Yemen, the soil was prepared for planting by the ard. narrow terraces on steeper land were generally planted with trees instead, which provided greater stability to these more fragile terraces.
Water for these agricultural terraces was provided by various sources.
some water was provided directly through rain falling on the terrace itself.
supplemental water was provided by run-off from uphill slopes, which might have been prepared and cleared for rainfall collection. Runoff water was important because it brought upstream nutrients to the soils of the ter-race, reducing or eliminating the need for fertilization of the fields.39 ghayl, or springwater, was also used if available, and because of the more reliable nature of this water, terraces fed by ghayl tended to be the most produc-tive.40 In addition, in more complex terrace systems, water from higher up the hillside might be delivered to lower-lying terraces though subterranean conduits built of masonry. The same conduits also allowed excess water to be drained off safely in extreme rainfall events.41
Figures 1.2 and 1.3 illustrate the variety of ways in which terracing was used within the traditional Arabian Peninsula. The first photograph, taken in Yemen, shows mountaintop terraces that clearly depend mainly on direct rainfall, though runoff from the higher slopes to the west might contribute to field moisture as well. In this case, the terraces clearly serve to retain soil from being lost downslope to erosion. In contrast, the second photograph depicts the use of terracing in a mountain village in oman.
Water in this example was provided by a combination of slope run-off and ghayl. The terraces in these cases were created to benefit from upstream erosion, capturing and maintaining moisture and soil washed from higher elevations, and to provide a flat surface for farming in a naturally rugged landscape. unlike the Yemeni case, some of the terraces in oman were
cultivated as bustan gardens, with a variety of different plants fed by irriga-tion channels under the canopy of the palms. Bustan farming, it should be noted, is more crucial to agriculture in oman than in Yemen; in Yemen, the summertime heat is moderated by monsoon cloud cover and moisture, allowing crops to be grown in open fields.