• publisher: Govt. Print. Off.
  • creator: James William Nelson , United States Bureau of Soils
  • contributor: unknown library
  • mediatype: texts
  • years: 1918
  • pages: 173
  • language: English
  • notes: At head of title: U.S. Department of Agriculture Bureau of Soils in cooperation with the University of California Agricultural Experiment Station.
  • download: pdf file