00729cam a22002291 4500 agr49000449 DLC 20260227111011.0 770513s1949 nyuab b 000 0 eng agr49000449 (OCoLC)2962014 DLC TNJ DLC premarc SB187.U6 M3 Martin, John H. (John Holmes), 1893- Principles of field crop production [by] John H. Martin [and] Warren H. Leonard. New York, Macmillan Co., 1949. ix, 1176 p. illus., maps. 22 cm. "References" at end of each chapter. Field crops United States. Leonard, Warren H., 1900- joint author. 11036 11036