Walter Lowdermilk's Journey: Forester to Land Conservationist
NRCS History Articles
by Douglas Helms
Reprinted from Environmental Review 8(1984): 132-145. This paper was given at "History of Sustained-Yield Forestry: A Symposium," at the Western Forestry Center in Portland, Oregon, on October 18-19, 1983, coordinated by the Forest History Society for the International Union of Forestry Research Organizations (IUFRO) Forest Group (S6.07). The proceedings, edited by Harold K. Steen under the same title, were published by the Forest History Society, 109 Coral Street, Santa Cruz, CA 95060 in 1984.
Walter Clay Lowdermilk often described his profession as reading "the records which farmers, nations, and civilizations have written in the land." Few others have belonged to this profession. Certainly few had the inclination, ability, and opportunity to indulge in it as did Lowdermilk. The profession required expertise in many fields of study, but as practiced by Lowdermilk it was not a purely academic exercise. Rather he sought an ambitious objective--a permanent agriculture for the world. Through an understanding of human activities in the past and the earth's response, he hoped to "find the basis for a lasting adjustment of human populations to the Earth."1
Lowdermilk became a member of the early twentieth century conservation movement in the United States, a movement with a strong scientific bent.2 The scientists held that treatment of natural resources should be in accordance with scientific principles, not propelled by emotionalism or untested theories. Lowdermilk's inquisitiveness, intellect, and foreign travel took him on an unusual professional journey. Veering from forestry, he circled the field of land conservation--a field encompassing several sciences and disciplines. In foreign travels Lowdermilk found situations where people's relationship with the land had reached a precarious balance, or an imbalance resulting in famines. Coping with these situations required an integration of knowledge from science, technology, and engineering. Other scientists in the movement had not embraced a multidisciplinary approach. The abundance of natural resources in the United States, and the low population density, had allowed scientists of his era to view solutions to resource problems as a set of discrete alternatives--a view which further entrenched their fealty to their chosen disciplines.
Walter Lowdermilk was born on July 1, 1888, in North Carolina, but spent his childhood at numerous points westward during the family's extended migration to Arizona. As a college student at the University of Arizona, he realized his dream of earning a Rhodes scholarship. The curriculum at Oxford permitted him time to study forestry in Germany. Herbert Hoover's Commission for Relief in Belgium called Lowdermilk and other young Americans in Europe to interrupt their studies. After the scholarship years, he served as a ranger in the Southwest for the Forest Service. Returning from World War I, he became the Forest Service's regional research officer in Montana.3
A man who enjoyed research work, he had found a position that offered satisfaction. Given his ability, there was opportunity for advancement. But he was not to remain on that career ladder. Soon he would be in China, where, he later recalled, the "full and fateful significance of soil erosion was burned into my consciousness."4
Through the years in England and afterward, the young forester had corresponded with Miss Inez Marks, a friend from Arizona. On leave from her missionary work with the Methodist Church in China, she agreed to meet him at the Rose Bowl, New Year's Day, 1922. Marriage plans quickly followed. Her entreaties that China desperately needed talented scientists led to his applying for a position with the University of Nanking's school of agriculture and forestry. The couple married in August and departed for China in September 1922. Lowdermilk's charge, for a small salary, was to assist in solving the flooding problems and resulting famines. Exactly how a forester was to help with food production remained a mystery as he attended university classes to learn Mandarin during the first year.5
An expedition to the Yellow River solved the mystery. There he stood atop a section of the 400-mile-long dike that held the river 40 to 50 feet above the flood plain. This marvel was a result of Chinese labor necessitated by silting of the river's channel--aggradation in the terms of earth scientists.
Lowdermilk set out to find the source of the silt.6 In spring 1924, O.J. Todd, engineer of the International Famine Relief Commission, accompanied Lowdermilk on a two-thousand-mile trip on the watersheds of the Yellow and Wei rivers. Todd's mission was to study the Wei-Peh irrigation project. Few foreigners had visited the area of northwest China where the pair completed a third of the journey afoot or on mulecart or muleback. In Shensi province, they found a plateau consisting of deep, undulated deposits of loessial soils. Depth, fertility, and erodibility made these fine, wind-deposited soils prime locations for man-induced erosion. In the deforesting activities of the people Lowdermilk found the reason for the gigantic six-hundred-foot-deep gullies, "So great is the demand for fuel and wood that the mountainsides are annually shaved clean of all herbaceous shrub and tree growth."7 Paradoxes abounded on the trip. Temple forests, reproduced naturally and protected by Buddhist priests, provided evidence of the denuded hills' capability for sustaining vegetation. Bench terraces festooned some slopes. Yet some of the best agricultural land on the level, alluvial plains was used for timber production under irrigation. Surrounding hills were little used for timber.
The pair visited Sianfu, the capital city of China during its Golden Age, where Todd wanted to inspect the irrigation works. The area retained little of its former prosperity, which Lowdermilk conjectured had flowed from a great irrigation project which was now "silted up and out of use." The forester returned to his post at the University of Nanking with an impression of "colossal erosion" contrasted with "evidences of former grandeur." Already he had decided to expand his study of the sciences involved with natural resources to include the actions of people as well. The trip had provided "abundant material for an entrancing study of man's relationship to nature."8
Historical research revealed that the Yellow River had changed course eight times since A.D. 11. Several times the river had been restrained by dikes only to break free. Once it emerged four hundred miles from its former outlet. Dikes, therefore, were essential to using the plain for agriculture. But building higher dikes, Lowdermilk concluded, was not a lasting solution unless the aggradation of the river was reduced by checking the supply of silt.9 Lowdermilk's supposition that erosion caused frequent and severe flooding had been recognized in the United States, but only on the small water courses, not on the lower reaches of major rivers. The China experience--siltation of a major river channel as a cause of flooding and channel relocation--was on a scale unknown in the United States.
Lowdermilk's recommendation for flood control gave some indication of the breadth of his training in sciences, especially geology, and his ability to assimilate the findings into a solution. The Yellow River and her tributaries had excavated a deep channel into the plateau created by the wind-deposited soils. Recognizing that removal of vegetation allowed runoff to carve gullies in the loessial plain and that gully wash accounted for most of the silt, he proposed attacking erosion by planting trees on the talus slopes at the foot of the gullies. The forested gullies would be guarded and managed by villages as community forests to provide wood. Undissected portions of the loessial plateau could be used for agriculture. Where and when possible, check dams should be used to raise the base level of streams and prevent incision by the gullies farther into the plateau.10 Treatment of the watershed was directly tied to famine prevention. He concluded that soil and water conservation were urgently necessary to increase the productivity of this region of China.11
Lowdermilk was not content to base his recommendations exclusively on empirical evidence. Certainly the scientific forestry school, whence he came, demanded another explanation. Using the runoff and erosion plot study method devised by F.L. Duley and M.F. Miller at the University of Missouri, he and his Chinese associates set up plots on twenty temple forests and on denuded areas for comparison. After three years of study, he presented the findings. Runoff from denuded areas greatly exceeded that of temple forests or areas reclaimed through reforestation. The main reason for the excess runoff, he believed, was that particles of soil on the denuded areas clogged the pores of the soil surface. Forest litter arrested this action.12
Further study convinced Lowdermilk that forty to sixty percent of the uplands in northern China had little cover to retain runoff. So great had been the rapid runoff that it had reduced evaporation and brought on a period of decreased precipitation in the area. With this argument, Lowdermilk projected a hypothesis that he would later apply to other lands. Scholars had long been presented with anomalies of twentieth century poverty contrasted with evidences of former civilizations which possessed a high degree of culture and prosperity. Some scholars, notably Ellsworth Huntington and Baron Von Richthofen, found the answer in climatic change. In the case of north China, Lowdermilk not only saw soil erosion and flooding as the reason for decline, but also claimed their effects as the reason for a climatic change.13
The communist uprising of March 24, 1927, in Nanking ended the Lowdermilks' stay in China. Leaving behind all possessions, they barely escaped. At the University of California, he combined study for a Ph.D. from the School of Forestry (minors in soil science and geology) with research at the California Forest Experiment Station. Here he reentered the fray over the effects of vegetative cover on runoff, erosion, and flooding. On one of his treks in China, Lowdermilk had heard the proverb, "Mountains empty--rivers gorged." He judged the application of timber management in that locale to be superior to any system he had observed in Germany.14 The Chinese and other civilizations had recognized the value of forest cover and acted upon their observations. Scientists in the conservation movement demanded more than proverbs for proof, and the influence of forest cover on soil erosion and streamflow had been warmly debated by hydrologists, engineers, and foresters.
In the United States, the advocates of scientific forestry on public lands, who emphasized a sustained supply of forest products as the major benefit of public ownership, received support from irrigation farmers who needed an assured supply of water--water that was free of ditch-clogging silt. In their support of watershed protection they relied on observation, and were undeterred by the absence of scientific proof. Lines of inquiry into watershed treatment resulted not only from the inquisitiveness of the scientist's mind but also from these public policy questions. Legislation for forest reserves, upstream reservoirs for flood control, and comprehensive water development programs touched off research by the government agencies affected. The research results could seriously alter their project plans and budgets.15
Lowdermilk believed that builders of large engineering works downstream should provide for soil erosion control in the catchment areas, as a portion of the project's benefits was attributable to watershed management. The value of watershed management, however, had not been satisfactorily measured and described. A review of the literature convinced Lowdermilk that most watershed studies which tried to measure the influence of one factor on runflow were flawed. In an open setting there were too many variables which were observed, not measured. He must create a laboratory type experiment which would isolate the factors, measure them, and explain the processes.16
In his study of the influence of forest litter on runoff and erosion, he used rainmaking machines, soil profiles transferred to tanks, and measuring instruments of his design. In 1929, he presented the confirmation for what he and others had observed. On bared soil the raindrops splashed up muddy. As muddy water percolated into the soil profiles, "fine suspended particles were filtered out at the soil surface."17 The thin layer thus formed reduced percolation and increased runoff. The water-absorbing capacity of forest litter had little influence on runoff. However, by keeping the water clean, the litter maintained the soil profile open to percolation. The experiments confirmed a hypothesis that Lowdermilk had first presented at the Third Pan-Pacific Science Congress in 1926 at Tokyo.
Lowdermilk did not elaborate on the implications of his research. Perhaps this omission was in keeping with the accepted method of presenting the results, but the value to soil conservation was obvious. If forest litter served not as an absorber of water, but as a buffer between the rain-drop and the ground, then any vegetative land cover could be valuable for soil erosion control. Pastures, hay crops, any close growing crop, or crop residues could serve as barriers to the erosion process.
As Lowdermilk pioneered in the field of reading records written in the land and applied scientific explanations, he needed new terminology. At the Stockholm meeting he seized the occasion to introduce two terms for the conservationist's lexicon. "Accelerated erosion" arose from the "artificial disturbance of factors which controlled the development of soil profiles." In the absence of such disturbances, one could view any erosion as the "geologic norm of erosion."18
Back in California, Lowdermilk set about measuring the other factors in runoff and erosion that would provide a "basis for enlightened management of watershed areas."19 Experiments focused on elements of the hydrologic cycle: precipitation, temperature, evaporation, runoff, infiltration, percolation, and transpiration. The Agricultural Appropriations Act of 1929 provided funds to U.S. Department of Agriculture agencies for erosion and runoff experiments. The research program made it possible to establish experiments on a large, isolated watershed. The San Dimas watershed of southern California provided an excellent opportunity to test the effects of watershed management on water yield. Expanding towns and citrus orchardists at the foot of the watershed had to dig increasingly deeper wells to reach underground aquifers. Whether the vegetative mantle should be burned to reduce transpiration or protected from fire for maximum ground water supplies was a matter of controversy. To demonstrate and measure the relationship of percolation to aquifer levels Lowdermilk had Civilian Conservation Corps enrollees build water spreading structures which led to a gravelly basin where the silt settled out and water percolated to the aquifers.20
Though Lowdermilk had devised the research plan for San Dimas and supervised the early work, he was not destined to see it to completion. Events and foreign travel again intervened to set Lowdermilk back on the path to land conservationist. When the Soil Erosion Service was established in 1933, Assistant Secretary of Agriculture Rexford Tugwell, who had toured the California experiments, insisted that Lowdermilk serve as Assistant Chief to Hugh Hammond Bennett.21 Their personalities differed greatly, but on the matter of conserving farmland there were points of agreement. Bennett, like Lowdermilk, emphasized that conservation was not exclusively a matter of maintaining fertility on hillside soils. Lowdermilk had seen the effects on the Yellow River flood plain. Bennett, as an inspector of soil surveys in the South, had seen the same effects on a smaller scale in flood plains of the South where sand, and eventually gravel, piled up on flood plains. Looking at the situation in strictly agricultural terms, the use of erosion-inducing farming practices on some of the least valuable lands was preempting the most valuable from food production.22 Thus, they held the belief that conservation should be applied not just to the individual farm, but to an entire watershed.
Both men also viewed the coordinated use of vegetal and engineering measures on the individual farm as necessary for soil conservation. Lowdermilk, the forester, realized that erosion control in a country such as China with famine problems could not be achieved strictly by vegetal control. Bennett had obtained his conservation experience in the South, where the broad-based channel terrace had been invented to contend with erosion problems. He saw the limitations of engineering measures as well as their values. In Central America, he had seen coffee interplanted with bananas, plantains, and other fruit-bearing trees on steep land, where they nonetheless provided excellent erosion control.23 As an institutional goal, the young Service would attempt to assimilate and coordinate many disciplines into its conservation program. Individually, the Service's field men working on farms should be what Lowdermilk called "land doctors," general practitioners of the conservation sciences.24
In addition to working with farmers on watershed-based demonstration projects in critical erosion areas, the Service had a considerable research program which Lowdermilk directed. The experiment stations established under the 1929 Agricultural Appropriations Act were already engaged in research on terracing, crop rotations, stripcropping, tillage methods, and their value to soil conservation. Lowdermilk added runoff and erosion studies that included the collection of hydrologic, climatic, physiographic, erosion history, and sedimentation data. While these fifty-year long watershed studies were to be comprehensive, particular aspects were related to debates among scientists and government agencies. The bedload studies involved the degree of sediment sorting by stream action and the amounts deposited in stream channels. In a practical way, the studies countered the accepted method of measuring erosion from a watershed by simply measuring the silt emerging at the watershed's lower end.25
In 1938 chance again intervened in Lowdermilk's life. As usual, he seized the opportunity. Representative Clarence Cannon suggested that a survey of the Old World could be useful in the United States' efforts toward a permanent agriculture. The trip, August 1938 to November 1939, involved more than twenty-five thousand miles of automobile travel in Europe, the Mediterranean area, and the Middle East. Here he perfected his art of reading the land for evidence of past use and misuse. Before undertaking surveys in each country, Lowdermilk consulted agriculturalists, scientists, and officials. Geologists and archaeologists were especially interested, and valuable to Lowdermilk in explaining the cultural and physical factors involved in land use. In addition to searching for soil conservation and flood prevention measures that might be imported to the United States, Lowdermilk was engaged in what he called "agricultural archaeology." Ruins of some pre-industrial civilizations indicated a prosperous agriculture, although these areas now had serious resource problems. What events brought about such conditions? What were the lessons for contemporary civilizations?26
Lowdermilk's land-read records of past civilizations appeared in numerous articles. Indeed, there were "Lessons From the Old World to the Americas in Land Use," as Lowdermilk titled an article in the annual report of the Smithsonian Institution. He gladly noted the cases of wise land use through centuries, but was usually obliged to find a story of deterioration.27 The Soil Conservation Service published a summary, Conquest of the Land Through 7,000 Years, in 1953 and followed it with several reprintings until more than one million copies were distributed. Readers who know Lowdermilk only through this publication have perhaps a truncated view--that of the globe-trotting chronicler of calamities awaiting civilizations that abuse their resources. He realized that a civilization's decline could not be interpreted solely on the basis of soil erosion. However, in writing the pamphlet, he embarked on a didactic mission aimed at all Americans, not just farmers. Soil fertility was a matter of concern for the farmer. Maintaining the medium for fertility--the physical body of soil resources--concerned the nation. Without it, "liberty of choice and action" was gone.28
World War II terminated the trip in Europe but it opened a new opportunity, a return to China. At the behest of the Chinese government, Lowdermilk undertook the dangerous journey to advise the Chinese about increasing their food supply. During the intervening years in the United States, he had continued to study the agricultural archaeology of China. While in China he bought gazetteers, local histories, which Dean R. Wickes, a Chinese language specialist, then researched for evidences of erosion problems. This research showed that in northern China, an area with a small percentage of level land, the population had increased threefold since the mid-eighteenth century. This rapid population increase sent people to the hills for firewood and arable land, without any orderly installation of engineering measures for soil conservation. Unlike areas of central and southern China, they had no elaborate bench terraces to protect farmland. The gazetteers provided accounts of clearing the slopes, removing farmland from the tax rolls as wasteland, and abandoning homes along streams due to frequent flooding.
The forester turned historian found an impressive case for the effects of erosion on agricultural productivity in the Wei-Peh irrigation system along the Wei River. Begun at least as early as 246 B.C., the system had irrigated 400,000 acres. According to Lowdermilk's research, the area became prosperous and dominated the surrounding territories. A Chinese chronicler believed the reason for prominence lay in the assured food supply: "Thereupon Kuanchung became fertile territory without bad years; whereupon Ch'in became rich and powerful and finally conquered the feudal princes." The Chinese remade the irrigation system eleven times during twenty centuries in their never-ceasing battle with silt. Piles of excavated silt thirty-five feet high lay on the canal banks in the fourteenth century. Usually they preferred digging new canals to clearing out sediment. During the eighteenth century, while the Chinese labored ceaselessly at keeping the canals open, the irrigated acreage was only one-tenth its original size. American engineers, under the direction of Lowdermilk's old traveling companion O.J. Todd, used modern equipment and reinforced concrete to rebuild the project. Even with modern equipment the problems remained, because water entering canals following heavy rains in 1931-32 measured 46 percent silt by weight. The irrigation farmer in China, like his counterpart in the Western United States, had to look to watershed protection as a source of silt-free water.29
Controlling erosion on the upper reaches of watersheds became a passion for Lowdermilk's generation of conservationists. They favored land cover for increased absorption and engineering works for the controlled disposal of water without erosion. The upstream reservoir on the small watersheds was an integral part of the river development--an assertion that was often contested. Proponents of the control and use of headwaters had stated their case in the publications Little Waters and Headwaters: Control and Use.30 In the later 1940s they had another opportunity when Morris Cooke, a force behind Little Waters, became chairman of the President's Water Resources Policy Commission. Lowdermilk assumed chairmanship of the Committee on Standards for Basic Data. The Cooke and Lowdermilk views held sway in the committee report that emphasized a comprehensive, interdisciplinary approach. The interdependence of land and water called for watershed management which had been neglected due to "our natural endowment and relatively low population density." Furthermore, the small watershed, the unit of watershed management preferred by the authors, was a cultural unit. The watershed unit had to be small enough so that residents understood its influence on their lives. Then they would devote the time and money needed to bring it to fruition as a community watershed. Lowdermilk's experience in semi-arid climates came through in the committee's attitude toward flood control. Where feasible, reservoirs should not be used solely to control floods, but also to store storm waters for later use.31
The attitude toward reservoirs and engineering works illustrated, as did other beliefs, the length of Lowdermilk's professional journey from forestry. He had come to believe that the earth had to be prepared to accept the benefits of rain. In his system of "physiographic engineering," reservoirs could be designed to perform functions other than storing water and controlling floods. For example, reservoirs could create intermediate base levels of stream cutting which reduced head cutting of tributaries. Downstream, the clear water flowing from a reservoir could excavate alluvial fill in a channel and reduce the frequency of flooding.32
As a man of many sciences, Lowdermilk also became a man of many reputations. Most Americans knew him from his call to heed the lessons of the Old World in conserving soil resources. Archaeologists and historians searched the physical and documentary remains of civilizations for refutation or confirmation of his land reading expertise. In the international scientific community his reputation rested on the hydrologic studies. The Chinese and Israelis recalled his humanitarian activities to increase food production.
Lowdermilk's experience in Israel illustrated that facility in physical sciences which allowed him to interpret past land use patterns also made him a master at proposing measures for increased food production. During the trip to the Middle East in 1938-1939, Lowdermilk became inspired by the efforts of urban-born European Jews to reclaim land. Upon returning to the United States, he wrote Palestine: Land of Promise, which proclaimed that the land could once again support a large population. After retirement from the Soil Conservation Service he worked with the Israelis to implement some of the measures outlined in the book. Many Israelis favored technical assistance for agricultural development over direct food assistance. That sentiment was concisely conveyed when Minister of Development Mordecai Bentov coined the saying, "We don't need powdered milk; we need Lowdermilk."33 While there, Lowdermilk helped establish at Haifa a school to train conservationists, a school which later bore his name. The Lowdermilk School of Agricultural Engineering emphasized the basic sciences as preparatory to agricultural studies. Students took two years of mathematics, chemistry, physics, geology, and biology before moving on to the agricultural sciences. A job-related project in the fifth year was necessary to earn the degree.34
The fifth year requirement of field experience reflected the Lowdermilk experience. He believed that field work was a necessary component of research. In the Soil Conservation Service, field personnel were to be encouraged to suggest alternative ways of accomplishing conservation objectives. Field work, especially in an area such as China, where farming had been practiced for centuries, could uncover useful information. There was always the possibility that "some unheralded genius may have already found the solution to our problem, a solution in whole or in part if we know what we are looking for."35 After all, it was in the field, on the Yellow River, that Lowdermilk's career as a land conservationist began.
1 Lowdermilk, Walter C., "Down to Earth," in Transactions: American Geophysical Union (Washington, D.C.: National Research Council, 1944), p. 195.
2 For a discussion of conservation as a scientific movement see Hays, Samuel P., Conservation and the Gospel of Efficiency (1959; reprint New York: Atheneum, 1979), p. 2.
3 Brink, Wellington, "Walter C, Lowdermilk," Holland's 61 (December 1942): 8.
4 Lowdermilk, Walter C., Conquest of the Land Through 7,000 Years, Agriculture Information Bulletin No. 99 (1953; reprint Washington, D.C.: Government Printing Office, 1975), p. 13.
5 Walter Clay Lowdermilk Interview, p. 61, Bancroft Library, University of California, Berkeley.
6 Lowdermilk, Walter C., "A Forester's Search for Forests in China," American Forests and Forest Life 31 (July 1925): 427.
7 Lowdermilk, Conquest of the Land, p. 14.
8 Lowdermilk, "A Forester's Search," p. 4-46.
9 Lowdermilk, Walter C., "Erosion and Floods in the Yellow River Watershed," Journal of Forestry 22 (October 1924): 15.
10 Ibid., pp. 11-18.
11 Lowdermilk, Walter C., "Factors Influencing the Surface Run-off of Rain Water," in Proceedings: Third Pan Pacific Science Congress (Tokyo, 1926), p. 2147.
12 Ibid., pp. 2122-2147.
13 Lowdermilk, Walter C., "The Changing Evaporation-Precipitation Cycle of North China," Engineering Society of China 25 (1925-1926): 97-147.
14 Lowdermilk, "Forestry in Denuded China," Annals of the American Academy of Political and Social Science 152 (November 1930): 130.
15 For a discussion of some of the debates see Hays, Conservation and the Gospel of Efficiency.
16 Lowdermilk, Walter C., "Studies of the Role of Forest Vegetation in Surficial Run-Off and Soil Erosion," Agricultural Engineering 12 (April 1931): 108.
17 Lowdermilk, "Further Studies of Factors Affecting Surficial Run-Off and Erosion," in Proceedings of the International Congress of Forestry Experiment Stations, 1929 (Stockholm, 1929), p. 625.
19 Lowdermilk, Walter C., "The Role of Vegetation in Erosion Control and Water Conservation," Journal of Forestry 32 (May 1934): 531.
20 Lowdermilk Interview, pp. 121-129.
21 Ibid., pp. 133-134.
22 Bennett, Hugh Hammond, The Soils and Agriculture of the Southern States (New York: Macmillan Company, 1921), p. 283.
23 Bennett, Hugh H., "Agriculture in Central America," Journal of the American Society of Agronomy 17 (June 1923): 318-326.
24 Lowdermilk Interview, p. 160.
25 Ibid., p. 202.
26 Lowdermilk, Walter C., "Terracing Land Use Across Ancient Boundaries," mimeographed (Washington, D.C.: Soil Conservation Service, 1940), pp. 1-133.
27 Lowdermilk, "Lessons From the Old World to the Americas in Land Use," Annual Report of the Board of Regents of the Smithsonian Institution, 1943 (Washington, D.C.: Government Printing Office, 1944), pp. 413-427.
28 Lowdermilk, Conquest of the Land, p. 30.
29 Lowdermilk, "Forestry in Denuded China," pp. 127-141; Lowdermilk, Walter C. and Wickes, Dean R., "Ancient Irrigation Brought Up to Date," Scientific Monthly, 55 (September 1942): 209-225; "China and America Against Soil Erosion," Scientific Monthly, 56 Part I (May 1943): 393-413; Part II (June 1943): 505-520; History of Soil Use in the Wu T'ai Shan Area (North China Branch of the Royal Asiatic Society, 1938), pp. 1-31.
30 Person, H.S., Little Waters: A Study of Headwater Streams & Other Waters, Their Use and Relations to the Land (Washington, D.C.: Soil Conservation Service, Resettlement Administration, Rural Electrification Administration, 1936), pp. 1-82; Headwaters: Control and Use, Papers Presented at the Upstream Engineering Conference Held in Washington, D.C. September 22 and 23, 1936 (Washington, D.C.: Soil Conservation Service, Forest Service, Rural Electrification Administration, 1937), pp. 1-261.
31 A Water Policy for the American People: The Report of the President's Water Resources Commission (Washington, D.C.: Government Printing Office, 1950), pp. 123-125.
32 Lowdermilk, Walter C., "Physiographic Engineering: Land-Erosion Controls," in Transactions: American Geophysical Union (Washington, D.C.: National Research Council, 1941), pp. 316-320.
33 Conversation with Abraham Avidor, Foreign Agricultural Service, U.S. Department of Agriculture, December 2, 1983. Richard D. Siegel, Deputy Assistant Secretary, U.S. Department of Agriculture, brought this saying to my attention and Mr. Avidor, who grew up on a kibbutz and who knew Mr. Bentov supplied the details. Bentov was seeking to promote the development of agriculture and viewed the direct food assistance as an inhibiting factor. Avidor reports that the saying was quite prevalent in Israel in the 1950s.
34 Lowdermilk Interview, pp. 610-611.
35 Lowdermilk, Walter C., "Preliminary Report to the Executive Yuan, Government of China, on Findings of a Survey of a Portion of the Northwest for a Program of Soil, Water and Forest Conservation, 1943," typescript, p. 37, Soil Conservation Service History Office, Washington, D.C.