442 
Soluble silica, in soils, 70. 
Sonora wheat, 240. 
Sorauer, 12, 178, 183. 
Sorghums, 244. 
South Dakota, area, 26; deep and 
fall plowing in, 195. 
South Dakota Station, dry-farming 
in, 370; present status of dry- 
farming, 389. 
Sowing, see also Germination, 205- 
228, 415; and seed-bed, 212; 
failures due to, 205; implements 
for sowing, 317; method of, 225; 
time of, 212; in fall, 212; in fall, 
disadvantages of, 214; in fall, 
when preferable, 215; in fall and 
fallowing, 218; in fall and root 
system, 216; in fall, right time 
of, 216; in spring, when prefer- 
able, 215; depth of, 220; quantity 
for, 222; in various sections, 215. 
Spalding, 178. 
Spring, cultivation in early, 159; 
if wet, causes loss of soil-water, 
160. 
Springs, source of water, 334. 
Spruce, on dry-farms, 253. 
State aid, for dry-farm studies, 368. 
Steam, machinery in dry-farming, 
321. 
Stems, proportion of, 260, 261. 
Stewart, 284. 
Stewart and Greaves, 190, 263, 271. 
“St. John’s Bread,” on dry-farms, 
252. 
Stockbridge, 154. 
Stomata, description, number, and 
function, 172-174. 
Stooling, 223. 
Storing water, in soil, 94; depend- 
ent on pore-space, 102; by fall 
plowing, 126; by deep plowing, 
125; in Great Plains soils, 122. 
Straw, from dry-farms very nutri- 
tious, 275; header straw to 
retard evaporation, 150; header 
stubble conserves soil-water, 155; 
INDEX 
not to be burned, 156; ratio 
straw to kernels, 18; ratio to 
grain and climate, 261; relation 
of roots to, 216. 
Strawbridge, 393. 
Stubble, see also, Header, Straw; 
decay of header, 191, 230; for 
header and fertility, 290; header 
stubble and fertility, 228; header 
stubble and humus, 198; value 
of header stubble in transpira- 
tion, 191. 
Sub-humid area, and dry-farming, 
29; defined, 24. 
Sub-Pacific, type of rainfall, 39. 
Subsoil, characteristics of arid, 60; 
distinction between soil and, 61; 
importance of moist, 116; may 
be turned up in arid countries, 
126; meaning in arid countries, 
59. 
Subsoiling, and dry-farming, 126; 
an advantage of, 141; how 
accomplished, 308. 
Subsurface packer, 316; invented, 
362. 
Subsurface packing, disadvantages 
of, 364. 
Subterranean, water, quantity of, 
338. 
Sugar beets, on dry-farms, 254; on 
irrigated farms, 236; variation 
in composition, 268; water and 
yield, 346. 
Summer rains, cause loss of soil- 
water, 160; sometimes detri- 
mental, 130. 
Summer tillage, see Cultivation and 
Fallowing. 
Sunflowers, pounds water for one 
pound, 14. 
Sunlight, ‘effect on transpiration, 
177. 
Sunshine, over dry-farm territory, 
46. 
Swedish Select oats, 241. 
Sycamore fig, on dry-farms, 252. 
