36 BULLETIN 1173, U. S. DEPARTMENT OF AGRICULTURE. 
Lind on the two dates of spring plowing. These data are¥not 
contradictory, but merely emphasize the fact that differences in 
soil type, soil-moisture content, and subsequent precipitation may 
cause entirely different results from the same operation. {The 
heavier soil at Moro, with heavier rainfall, when given any (sub- 
sequent tillage whatever, tends to settle into a condition more nearly 
pi IWF SIWISE 1/H16 1917 1918 49/9 1920 192/ 
O 
MOPO, OPEG. | 
me ae 
HYNES 
avennees Ifo =a | NSS ee 
ey 
GS 
GO 
25 
NO FACKING = =——_-————_—— 
DOE FOTLAGE: ( FACH LD), ear ere 
SUPFIACE FACHED — eer 
Fa. 19. Annual and average acre yields, in bushels, of winter wheat in varying numbers of years at. Moro, 
Oreg., and Lind, Wash., when grown after summer fallow for which the land had been plowed in early 
summer and either not packed or packed with a subsurface or surface packer after plowing. 
resembling that treated with the packer than does the lighter soil at 
Lind under the lighter rainfall. As a result the packer had little 
effect at Moro, while it had some effect at Lind. 
There was no benefit in using the packer at Lind on the June (sum- 
mer) date, because the soil was less moist and packing did not affect 
the results. 
