Selecting a site
Inland rice cultivators had to carefully observe topography and water flow to select a plantation site. While European planters would have directed this selection process, the insights of enslaved Africans working closely with the Lowcountry landscape may have influenced their decisions. Developing the water control system essential for flooding and minimizing weeds in inland rice cultivation required not only precise construction of earthen embankments, but also detailed understanding of the Lowcountry landscape. Cultivators also had to choose where reservoirs and fields would exist in relation to watercourses and terrain. To retain water in the reservoir and rice fields, the soil had to include a substantial clay foundation to prevent impounded water from seeping out. Subtle elevation change, in some cases just three or four feet from sandy highlands to alluvial swamps, allowed different types of vegetation to take root, depending upon the ground permeability. In this way, study of native plant growth provided mid-nineteenth century cultivators some insight into soil composition. For example, longleaf pine and oak trees grew in well-drained sandy soil, while cypress and tupelo gum trees grew in less permeable soil, which was more desirable for building reservoirs.
Clearing dense forests and swamps for inland rice cultivation required extensive and strenuous labor. The basic inland rice field consisted of two earthen dams enclosing a low-lying area bordered by ridges. "Swamps had to be diked to separate land from water," observes historian Theodore Rosengarten, and this work was done by enslaved people who “cleared and chiseled [the floodplain] with hoes until it was as level as a billiard table.” Enslaved Africans and to a lesser extent American Indians removed dense hardwoods, such as bald cypress, tupelo, and sweet gum, with axes and saws.
Rice planter John Norris noted in 1712 that stumps and roots took twelve to fifteen years to rot out of the fields, so that slaves had to plant rice around these obstacles. Slashing and burning the fields expedited the decomposition process, as fire “softened” the landscape. Once rice fields were in place, enslaved laborers continued to burn the underbrush and hoe out weed roots to prevent recurring growth of competing vegetation. Field hands also spent January and February, the least active months of the crop’s growth cycle, burning leftover stubble on existing rice fields or clearing new acreage.
Ditches and embankments
Once slaves removed vegetation in inland tracts for rice cultivation, they then leveled potential fields to accommodate planting and water drainage. After the fields could drain standing water, enslaved people dug precise quarter ditches to remove floodwaters more effectively. By the 1730s, these geometrically shaped fields dominated the Lowcountry interior, often replacing the natural landscape of water systems of streams, banks, and knolls.
Slaves built up the embankments with available soil fill from adjoining drainage trenches. The dams on higher elevation contained stream or spring fed water to form a reservoir, or reserve, that would provide a water supply to the lower rice fields. Water dispersed from rainstorms and springs flowed downhill into the reservoirs, while watersheds pulled from creeks and streams. Once cultivators released water from the reservoir, a second dam retained water to irrigate rice plants and kill off competing vegetation. Located between these two earthen structures was a series of smaller embankments and ditches to channel and drain water effectively during the cultivation process. Inland planters found that land in the coastal plain of the Lowcountry was both level enough for rice cultivation, while also maintaining a sufficient angle of a two to three percent grade to allow drainage.
Rice cultivators used gates, or “trunks,” to control water flow from reservoirs onto the rice fields. Originally made from hollowed out trees, trunks were traditional West African devices used to regulate water flow through a conduit by plugging the end of Brassus palms. Enslaved Africans substituted cypress for this device in Carolina. Field engineers placed trunks in sloughs, or stream channels, so water ran efficiently out of the holding pond from the embankment's lowest point. Sloughs were an important feature for draining wetlands, because they served as a natural “gutter.” After floodwaters nourished the soil and rice crop, and killed competing weeds, slaves drained the fields through trunks located at the second embankment. The water released from these fields flowed downhill toward nearby rivers.
After the end of the U.S. Revolutionary War (1775-1783) the inland rice cultivation schedule consisted of three flooding stages, separated by periods when enslaved field hands had to remove weeds by hand from the drained fields. During the first flooding, or ”sprout flow,” water eroded the trench banks causing soil to cover the grain. Trunk minders, a critical skilled position on rice plantations filled by enslaved Africans, would slowly let one and a half feet of water onto the fields, so flowing would not wash away seeds.
The seeds sat underwater for approximately twenty- one days until the seeds sprouted and germinated through the soil. After this stage, trunk minders gradually drew off the water to prevent damaging the delicate crop. Fields dried for fifteen days and enslaved workers removed any competing weeds and volunteer rice. As the seedlings grew to a height of two to three feet, the trunk minders let out a second flooding, or “stretch flow,” for twenty-one days. During this flow, floodwaters would lift up the “trash” of pulled weeds and stalks. A second and possibly third hoeing took place during the forty-day period after trunk minders let the water off the fields. Finally, the harvest flow took place until the rice crop reached maturation. The harvest flow required the most amount of water because the flooding needed to be as high as the plants, to support the heavy panicle that was sprouting from the stalk.
This cultivation schedule varied slightly from the tidal irrigation method. Tidal planters incorporated an additional flooding in between the stretch and the harvest flows, called a “point flow,” because they had greater access to consistent water sources compared to the inland planters and their reserves. By relying on reservoirs, inland rice planters were more limited in the amount of water they could use.