Rice is an important crop in Arkansas, Louisiana, and Mississippi, and sugarcane is important in southern Louisiana. Controlling surface water and artificially draining the wet soils are major concerns of management. The area consists of level to gently sloping broad flood plains and low terraces. Most of the area is flat. The only noticeable slopes are sharp terrace scarps and natural levees that rise sharply to several meters above adjacent bottom lands or stream channels.
Swamps are significant in the extreme southern part in Louisiana.
Average annual precipitation -1,150 to 1,650 mm, increasing from north to south. In most of the area maximum precipitation is in winter and early in spring, decreasing gradually to a minimum in autumn. Along the Gulf Coast, maximum precipitation is in midsummer and early in autumn. Snowfall is negligible. The Mississippi River crosses the area from north to south, and many of its tributaries also cross the area.