United States Department of Agriculture
Natural Resources Conservation Service
Conquest of the Land
through 7,000 Years
AIB No. 99
PAGE 2
AGRICULTURE INFORMATION BULLETIN NO.99
Preface
“Conquest of the Land through 7,000 Years” is Dr. Walter Clay Lowdermilk’s
personal report of a study he made in 1938 and 1939. Despite changes in names
of countries, in political boundaries, and in conservation technology, the bul-
letin still has significance for all people concerned with maintaining and
improving farm production.
Lowdermilk studied the record of agriculture in countries where the land had
been under cultivation for hundreds, even thousands, of years. His immediate
mission was to find out if the experience of these older civilizations could help in
solving the serious soil erosion and land use problems in the United States, then
struggling with repair of the Dust Bowl and the gullied South.
He discovered that soil erosion, deforestation, overgrazing, neglect, and con-
flicts between cultivators and herders have helped topple empires and wipe out
entire civilizations. At the same time, he learned that careful stewardship of the
earth’s resources, through terracing, crop rotation, and other soil conservation
measures, has enabled other societies to flourish for centuries.
Much of what Lowdermilk learned and wrote about land use and soil pro-
ductivity began with his pioneering research work in China, where his wife was
a Methodist missionary. Following the communist Chinese uprising in 1927,
Lowdermilk and his wife returned to the United States. While he was earning
his Ph.D. at the University of California-Berkeley, he continued soil erosion and
watershed management research for the Forest Service. In 1933, he joined Hugh
Hammond Bennett at the just-created Soil Erosion Service as the assistant direc-
tor and later became the assistant chief of the Soil Conservation Service, prede-
cessor to the Natural Resources Conservation Service. As assistant chief,
Lowdermilk held primary responsibility for developing the r