共 14 条
[1]
CARLSON C. W., 1959, SOIL SCI SOC AMER PROC, V23, P242
[3]
HUME AN, 1956, 455 S DAK AGR EXP ST
[5]
PUMPHREY FV, 1959, 449 NEBR AGR EXP STA
[7]
ROUNDS W. T., 1951, MICHIGAN STATE COLL AGRIC EXPT STA QUART BULL, V33, P372
[8]
SHAW R. H., 1956, AGRON JOUR, V48, P313
[9]
SHAW RH, 1958, 457 IOW AGR EXP STA
[10]
SHUBECK FE, 1955, 213 MINN AGR EXP STA