FIGURE 2.-Atchafalaya River, lower Mississippi River drainage. Melville, La. (Taken by Engineering Division, United States Army Air Service) FIGURE 3.-Atchafalaya River, lower Mississippi River drainage, Melville, La. (Taken by Engineering Divi sion, United States Army Air Service) remain in timber. Many other fields, located mostly in the bluff region, have been wholly abandoned because the top soil has been allowed to wash away, thus rendering the land useless for further cultivation. In many places no adequate forest or other vegetative cover has become established on a great part of the abandoned land, and at the same time clear cutting, constant burning, and heavy grazing have reduced the protective vegetation on vast additional areas which have never been plowed. Hence there exists, in a locality of moderate to heavy rainfall, a series of catchment basins nicely calculated to discharge into the Mississippi, in the shortest possible time, the maximum amount of water burdened with the greatest possible amount of silt. The severely eroded condition of this section of the Coastal Plainthe Mississippi bluffs and silt-loam uplands-has resulted in large measure from the removal of the forest cover and the abandonment of cultivated fields. Before the advent of the white man, natural drainage apparently did not cause unduly rapid dissection of the fertile, surface soil-a yellow loam from 3 to 7 feet in depth; but after the hardwood forest cover was removed during the settlement of the country and following the abandonment of many large plantations during the Civil War, a considerable part of this region, unprotected by forest cover or agricultural crops, was subjected to severe erosion. Year after year the fields were invaded by gullies of everincreasing size and the fertile soil-of long geological growth-was carried away by the streams. In the portion of this drainage lying to the west of the Mississippi River approximately 41 per cent, or 2,500 square miles, of the forested land is in farm ownership, together with approximately 57 per cent, or 2,500 square miles, of the unimproved land. The remainder of this forest and unimproved land, which includes many swampy and overflow areas, is largely in the hands of lumber companies. To the east of the river, however, about 55 per cent (6,500 square miles) of the wooded and forest land, and about 23 per cent (2,300 square miles) of the unimproved land, is farm-owned; unfortunately this will tend to make Government purchase of land for forest purposes difficult in this region in which it is most needed. No State or National forests exist in any part of this watershed. As a whole, the region is still without stock laws, although Mississippi enacted such a law in 1927. Cattle range at large on any land not protected by fence; and such land includes practically all of the forested and cut-over land. Throughout the region it is customary to burn over annually, regardless of ownership, the woods and pasture land on which stock grazes; this custom arose from the belief that burning improves the range. Until recently these stockmen's fires, with other of various causes, were allowed to run absolutely unchecked, and they have lowered to a greater or less degree the protective value of lands not actually in cultivation. This is especially true of the upland portions to the east of the Mississippi River. Conditions of nonforested land.-Practically all the land within the lower Mississippi Basin was originally in either bottom-land hardwoods, upland hardwoods, or pine. Within the boundaries of the bottom land hardwoods type lay all that part of the drainage west of the Mississippi, except for a relatively small area of upland hardwood in eastern Missouri. To the east of the river was a narrow strip of bottom-land hardwoods with extensions running up the larger streams. North of the Big Black River in Mississippi the balance of the land was in upland hardwoods; south of the Big Black, pine predominated. To-day, as a result of clearing for agrirulture and lumbering, only a little over a third of the total area of all types remains in woodland and forest. Because of differences in crops raised, methods employed, and results produced by cultivation the improved land will be discussed with reference to the forest type within the boundaries of which it falls. The percentile and absolute areas in cultivation, by forest associations within drainages, are given in an accompanying table (I). Within the boundaries of the pine type, corn, cotton, and a little truck are the principal crops. All are open and intertilled, leaving the soil exposed to washing. Contour plowing, which affords some protection against soil wash, is fairly general throughout the type and almost universal on the steeper slopes and more erodible soils; terracing, which would be far more effective and is seriously needed in many places, is little used. Attempts have been made here and there to check erosion by means of brush. In general, even this precaution is evercised less than in the past, partly because of an increase in negro-tenant farming. Land is usually left without a cover crop during the heavy rains of winter. Plowing is shallow, and crop rotation is seldom practiced. In a country where cattle are left without shelter all or nearly all of the year, often on open range, little organic matter in the form of manure is available to add to the soil. Many eroded fields are abandoned and left to wash unchecked, while new fields, usually as steep and as unfitted for agriculture as the old, are cleared. As a whole, the cultivated lands in the pine type do more harm than good as far as flood control is concerned. Conditions on the improved land within the upland-hardwoods type are as bad as, if not worse, than those just described for the pine. Similar crops are raised, but contour plowing and terracing are in general less effectively employed; and the soils, especially those of the Mississippi bluff lands, are even more subject to erosion. Within the bottom-land hardwoods type the situation is vastly different. Drainage rather than contour plowing is generally needed and has been obtained on large areas in Louisiana, Mississippi, Arkansas, and Missouri. Cotton, corn, and sugar, with some truck and other minor produce, are the principal crops. Erosion is a minor factor on these lands and apparently tillage is beneficial rather than harmful in its effect on the absorptive power of the soil. Fields have continued to produce crops for over half a century instead of wearing out in half a decade as they often do on the upland slopes, and in some counties the amount of cultivated land actually increased between 1920 and 1925, a period during which the amount of cultivated land in the counties of the adjoining pine and upland hardwoods types decreased. This cultivated bottom land, however, lies where it can exert little or no influence in preventing floods, and is itself sometimes subject to inundation. The unimproved land not in forest varies greatly in character not only between forest types but also between different parts of the same drainage within a given type. The relative and absolute amounts within each type is given by drainages in an accompanying table (I). In the pine type much land was dropped from cultivation between 1920 and 1925, and a considerable area has also been dropped before and since that period. Much of this land is eroding so badly that there is little or no chance for natural revegetation to take place. Other unimproved lands, especially in the southeastern quarter of the pine region in the portion of the drainage in Mississippi, are cut-over longleaf pine land, grazed as open range, burned over annually or nearly annually, not reproducing to pine, and supporting but a relatively scanty cover of bunch grass and scrub oak. Still other portions are reproducing in whole or in part to shortleaf and loblolly pine and to hardwoods, or support a good grass cover, but as a whole the unimproved lands in the pine type exert a decidedly detrimental influence in flood control. The influence of the unimproved lands within the boundaries of the upland type is even more detrimental. In the upland hardwood type of the lower Mississippi as a whole a large aggregate acreage of formerly cultivated land was abandoned between 1920 and 1925; additional areas were abandoned before and after that period. As in the pine type, much of this abandoned land is eroding beyond any hope of natural revegetation. Some of the less badly eroded portions have been invaded by an effective cover of grass or of shortleaf or loblolly pine in the sections in which pine occurs; there are a few logged-off areas-never plowed-which are wholly or partially protected from |