70 YEARBOOK OF AGRICULTURE 19 4 8 Loss of organic matter^ on the other tricts that were being assisted by the hand, means a reduction of the pore Soil Conservation Service, 536,000 ac- space, greater density, and reduced soil tive conservation plans had been com- capacity for proper drainage and mois- pleted on January 1, 1948. These indi- ture circulation. Some of the clay soils vidual farm and ranch plans covered oh the very flat clay lands in the lake- about 148 million acres, of which 36 laid area of northern Ohio have lost percent (53 million acres) were used granularity as the result of continuous for cultivated crops at the time of row cropping to such a degree that planning. The plans revealed that only farmers are now putting in additional 31 percent, or 46 million acres, were tile drains in that locality between the suitable for cultivation. old tile drains that formerly were ade- Because of the steepness of slope, quate for high production. As an indi- droughtiness, susceptibility to erosion, cation of increased density of the soil low content of plant nutrients, shallow resulting from depletion of organic soil, stoniness, or other unfavorable soil matter, by constant oxidation through condition, more than 7 million acres continuous cultivation, mostly to corn have been found to be much more suit- and oats, it has been found possible able for close-growing , like to put 81.7 pounds of soil into a cubic- grass and legumes, than for row crops foot measure of the same type of soil or small grain. that formerly was filled with 65.5 I believe that such a shifting from pounds of the same soil type just across water- and soil-wasting practices, ex- the road. The altered pore space was tended to all farms and ranches of the a reduction from 60.3 percent in the country, will in itself be a substantial virgin soil to 50.5 percent in the culti- contribution toward control. vated soil, and the organic matter con- tent reduction for the corresponding THE AUTHOR«<- Hugh H. Ben- conditions was from 66 to 44.7 tons per nett has been Chief of the Soil Con- acre. The remaining pores w^^re small servation Service since April 1935. He and less effective as water channels. was Director of the Soil Erosion Service In the 1,839 soil conservation dis- from 1933 to 1935,

GRASSES THAT FIX

CHARLES J. WHITFIELD, ROBERT L. BROWN

SAND DUNES have been a problem Great Lakes, and in practically all of for centuries. The earliest modern ref- the inland States. erence to control was in 1316 in Permanent control of active sand Germany. Laws limiting the use of dunes can be accomplished only by dune lands have been enacted in establishing on them a vegetative nearly every country. The best esti- cover, either by natural succession or mate as to the area of the earth cov- by seeding. Mechanical structures stop ered by sand dunes is 3,200,000,000 sand movement only temporarily. acres—nearly twice the total area and Grasses have a major role in the fix- seven times the agricultural land area ation of sand dunes, but only a few of the United States. grasses arc widespread and important Sand dunes in the United States, on these sandy areas. For example, on not including those in , occupy the Pacific and Atlantic and on an area one-tenth as large as the area the shores of the Great Lakes, beach- of agricultural land. These dunes are grasses grow either as native or natu- found along the coasts, bordering the ralized plants. Dune-control work dur- GRASSES THAT FIX SAND DUNES 71 ing the past 200 years in this country cool temperate regions is illustrated has established the value of both by the Warrenton Dune Control Proj- American beachgrass and European ect at the mouth of the Columbia beachgrass on these coastal areas and in Oregon. Encroaching dunes for inland dunes. were menacing agricultural lands, Purple beachpea^ a legume native forts, military reservations, highways, on the Pacific and Atlantic coasts and towns, and resort homes valued in all along the Great Lakes, has been used at many millions of dollars. The dunes successfully in mixtures that give per- w^ere also threatening to impede an- manent cover on the dunes. nually the movement of nearly $300,- In the Middle West and the Great 000,000 worth of -going com- Plains States, switchgrass, big blue- merce m^oving at the mouth of the stem, sand bluestem, Indiangrass, and Columbia directly in the path of the giant sandrecd grass are outstanding. encroaching dunes. Sand grass, sandreed grass, Dune-control work was started in and yellow lyme grass were among July 1935. The men in charge first those listed as important dune-control studied the factors they believed con- plants in the 1894 and 1898 Yearbooks tributed to the continuance of active of Agriculture. These are found to be dunes by destroying vegetative cover: less effective, however, than switch- Fire, grazing by livestock, construc- grass, big bluestem, giant sandreed tion of roads and buildings, cultivation grass, and Indiangrass for permanent of sandy soils, and so on. They also in- fixation. vestigated the at the mouth of Among grasses that assume consid- the river that alter the ocean currents, erable local importance are side-oats because they cause scouring of the grama, sea-oats, sand lovegrass, weep- ocean bottom and wash sand shore- ing lovegrass, iceplant, and a strain of ward to cause dunes faster than vege- mammoth wild-rye. tation can stabilize them. The causes Indian ricegrass and sand dropseed determined, work was started to es- are well adapted to sand-dune condi- tablish a permanent plant cover ac- tions. They arc primary invaders into cording to the needs of the land. temporarily controlled dunes but tend In most cases permanent cover was to disappear when competition be- obtained in only two stages after the comes great, so that areas of sand often source of incoming sand had been con- are left unprotected. trolled by mechanical devices or by Most of the active sand dunes in the vegetation. The first stage required United States are caused by man's sand-stilling plants. The final stage abuse of the protective vegetative was the seeding or planting of perma- cover. The goal in dune control is the nent vegetation—grasses and legumes reestablishment of a dense, permanent or woody plants. cover of vegetation. The cover may be American beachgrass, European herbaceous (grasses and legumes) or beachgrass, and American dunegrass woody ( and trees). These types were used effectively for the first stage are not easily or quickly established of control. The first has been outstand- on infertile eroding subject to ing because it spreads by vigorous high-velocity winds. Provisions must be rhizomes and can persist longer than made for stilling the sand and for the the other species. orderly building up of the fertility and The first year, fertilizer applications organic matter in the surface until that provided 40 pounds of nitrogen vegetation of permanent types can be an acre insured a better sand-stilling planted. Permanent fixation of dunes cover and made possible early seeding has been efficiently accomplished in re- of the permanent cover. Seedings of cent years in a number of localities. permanent species were usually made Coastal sand-dune control in the at the end of the first growing season 72 YEARBOOK OF AGRICULTURE 19 48 where bcachgrass plantings had been Dalhart to determine ways and means {(utilized. Such sccdings could not be of stabilizing and utilizing sand-dune made before the end of the second or areas in the Southern Great Plains. third year without this fertilization. The method developed for dune fixa- Native species were good for use in tion included five steps: Gontrolling the permanent stage of control, but the critical or contributing area; deep they were expensive and scarce. On the listing between and around the dunes basis of several trials^ the following to catch the dune sand ; breaking down combination of native and commer- crests and lowering the dunes to a cially available species was selected point where they could be planted; and used for final control : Tall fescue, establishing temporary control on the Glatsop red fescue (a strain developed loose drifting sands by planting cover on the job from native stands), com- crops, mulching, and aiding the devel- mon ryegrass, purple beachpea, and opment of a weed cover; finally, - hairy vetch. The vetch was the key to ing the area for permanent control. successful establishment of grasses; the The principal method of temporary beachpea provided the long-lived leg- control was planting sorghum as a ume in the mixture. cover crop for grass establishment. As in the first-stage plantings, a fer- Three types were outstanding—Sudan- tilizer application at seeding time as- grass, broomcorn, and Black Amber sured success with permanent seedings cane. Western wheatgrass drilled wdth if the vetch was included. An applica- a 12-inch, spaced-row grass drill on tion of 300 pounds an acre of ammo- 20-inch spaced rows of broomcorn nium phosphate (16-20-0) gave best made a perfect stand. Seedings of a results. Seedings without vetch failed. mixture of blue grama, side-oats The vetch provided protection against grama, sand dropseed, and sand blue- wind and intense light, protected the stem on 20-inch spaced rows of cane more slowly developing species, and (which volunteered heavily) produced supplied organic matter. Seedings were a good stand. made in the early fall in the mild The first work at Dalhart to estab- climatic conditions that exist on the lish grass for dune fixation was wdth west . Stabilization progressed mulch. Hay of giant sandreed grass rapidly, and the shifting dunes were wdth viable seed in the heads was tied down with vegetation. spread over a dune. A good stand was The plantings are being maintained obtained. to assure permanent dune fixation and Sand bluestem, Indiangrass, switch- give protection to farm, military, and grass. Ganada wild-rye, and western other properties to the leeward. wheatgrass w^ere found to be most ef- Similar work has been done on the fective in reducing wind velocity at the dune areas of Michigan, New York^ surface and binding the soil wdth root and Massachusetts, and at other points growth. Weeping lovc^grass, w^hich pro- along the Pacific and Atlantic coasts; duced heavy forage when planted slight variations in planting and man- alone, did not hold up well in mixtures. agement from those at Warrenton In southeastern Golorado, near were due to differences in proposed Gaddoa, permanent sand-dune stabi- uses of the land, type of sand, climate, lization eliminated the need of re- and plants used. routing a transcontinental railroad Sand-dune control in the Great across the Arkansas River. The prob- Plains area is typified by the Dalhart lem was one of controlling hundreds of Sand Dune Stabilization Project in the acres of loose, sandy material in a re- Panhandle of Texas, and the Gaddoa gion of low rainfall. The dunes wxre Sand Dune Stabilization Project in leveled and shaped with a bulldozer to southeastern Golorado. conform as nearly as possible to the un- In 1936 studies were started near dulating topography of the surround- GRASSES THAT FIX SAND DUNES 73 ing terrain. The dune areas were then could not be established without pro- seeded to mixtures of grasses with a tection, a crop of cereal rye at the rate double coulter disk-type drill. Switch- of 30 pounds an acre was drilled to es- grass, sand bluestem, big bluestem, tablish a covering in which perennial sand dropseed, side-oats grama, little vegetation could be seeded. On the blucstcm, sand blow-out grass, giant most severe sites on active dune areas a sandreed grass, sandreed grass, Can- mulch of straw and manure w^as disked ada wdld-rye, blue grama, and w^estern into the land before seeding. The same wheatgrass were among the grasses mixture that was used on the more pro- seeded on these dunes. tected areas was then used for perma- Following the seeding, a 2-inch nent stabilization on the Oregon site, straw mulch was applied and rolled where annual precipitation is only 10 W'ith a w^cightcd subsurface packer to inches. At Tooele, where the annual hold the straw in place. The mulch precipitation is 13 inches, a mixture of tended to reduce the evaporation of sand dropsecd, Indian ricegrass, crest- surface moisture, lower the soil tem- ed w^heatgrass, and western wheatgrass perature, and protect the young grass w^as used. plants from the sweeping action of the The control of coastal sand dunes in surface sand. warm temperate regions having sum- The tall grasses—big bluestem, sand mer rainfall is illustrated by the bluestem, giant sandreed grass, sand Gulf coast dunes in Kenedy County, dropsecd, and side-oats grama—were Tex. Active dunes are found in many the best for stabilizing these sandy parts of the Gulf coast; the most exten- soils. They were more effective than sive are in Kenedy County, where it is the short grasses because their height estimated there are more than 100,000 cut down wind action and produced acres of dunes. Some of the important more mulch for the protection of the factors that prevent natural vegetative soil. Giant sandreed grass was further stabilization of these dunes arc over- effective because of its ability to spread grazing, failure to control small blow- ]3y rhizomes. outs, erratic precipitation and periods As a result of construction activities of drought, and large rodent and insect on the Tooele Ordnance Depot area in populations. Natural vegetative succes- Utah and on the Umatilla Ordnance sion w^hen allow'cd to develop has effec- I^epot area in Oregon, sand dunes of tively stabilized dunes in this locality. small size, but hazardous to efficient In the early stages of succession, operation of these depots, were de- such plants as dune paspalum, cam- veloping. A large part of a 21,000-acre phorweed, and sandbur are found. area was affected. With the destruc- These are followed by perennials such tion of the native vegetation, the loose, as witchgrass and purple lovegrass, sandy soils began to shift so severely both rhizomatous plants; signalgrass; that it was impossibles to stabilize them and others. Stabilization is assured by natural reseeding alone. A survey w^hen subclimax species, such as sea- was made, and control by vegetation, coast bluestem, crinkle-awn, finger- rather than mechanical methods, w^as grass, and false-gam a replace the in- initiated at great savings of public itial invaders. Grasses such as swatch- funds. grass, big bluestem, and Indiangrass, On the more favorable areas, where w^hich are of the climax vegetation on there was some protection, the blow-- these and similar soils throughout much outs W'Cre seeded to a mixture of sand of the Great Plains and Middle West, dropsecd, Indian ricegrass, and crested may eventually become established if wheatgrass in Utah and bulbous blue- the area is well managed and is lightly grass and crested w^heatgrass in Ore- grazed. gon. Where the dunes to be controlled Artificial stabilization of these dunes were unprotected and small seedlings has been by mulching with straw or 74 YEARBOOK OF AGRICULTURE 19 4 8 other organic material and either en- Chicago, Since 1926 he has carried on couraging native vegetation or seed- ecological studies, including investiga- ing to subcHmax grasses. tions of grasses and other vegetation in The principles of dune fixation are relation to the control of sand dunes. the same throughout the country, but Since 1937 Dr. Whitfield has been with the materials used to attain the goal the Soil Conservation Service as project will vary in different sections. First, in- supervisor of the Amarillo Conserva- coming sand on any area must be tion Experiment Station in Texas. His stopped at or near its source by vegeta- primary interest has been wind erosion tion or mechanical operations. Second, investigatiojis. the dune area must be returned to its Robert L. Brown is a native of Mon- original topography or to the topog- tana and a graduate of Oregon State raphy of surrounding areas, either in College. He joined the Soil Conserva- the preparation for planting or in tion Service in 1934 and has worked planting by selection of plants that will on the control of eroding sand dunes conform to topographic surroundings. and as a technical consultant on dune- Third, initial sand-stilling cover must control problems. He has visited all be placed on the active dune area. This major sand dune areas in the United may be done by planting sand-stilling States to study their causes and meth- species such as European or American ods of control. Mr. Brown is assistant beachgrass, or mammoth wild-rye, or chief of the Regional Nursery Division, by mulches. Fourth, perennial vege- Soil Conservation Service, Portland, tation such as sand bluestem, pur- Oreg. ple beachpea, crested wheatgrass, Simon E. Wolff, Clifton Etter, Glenn giant sandreed grass, red fescue, and W. Eaton, Jr., Albert F, Dodge, Dr. switchgrass must be seeded to insure A. L. Patrick, A. D. Slavin, and Vic- rapid development of permanent dune tor A. Surface of the Soil Conservation control. Fifth, extreme care is always Service supplied some of the details necessary in the management of the given in this article.

[See also: The Meek that Inherit THEAUTHORS^^ Charles J.Whit- the Earth, by Agnes Chase, page 8; field has degrees from Iowa State Data on the Seed a7id Culture of Com- Teachers College^ the University of mon Grasses and Legumes, in the sec- Nebraska, and the University of tion. Grass in Charts and Tables^]