438 
in, 132; fertility of dry-farms, 284; 
wheats in, 240; present status 
of dry-farming in, 384, 386. 
Oregon Station, dry-farming in, 370. 
Organic matter, see Humus. 
Osmosis, process of, 168. 
Oxygen, in air and carbon dioxid, 
172; in soil formation, 55; in 
germination, 207. 
Pacific, type of rainfall, 39. 
Packer, subsurface, 316. 
Pagnoul, 185. 
Palestine, present status of dry- 
farming in, 397. 
Palouse Blue Stem wheat, 240. 
Palouse country, 385. 
Parsons, 252. 
Payne, 358, 367. 
Peach, dry-farm peach orchard in 
Utah, 251. 
Peas, pounds water for one pound, 
14, 15, 16; water absorbed by 
seeds of, 209; repeated drying 
in germination, 218; for nitrogen, 
297; variations in composition, 
268; field, 249. 
Pearl potatoes, 254. 
Phosphoric acid, in soils, 69. 
Physical agencies, of soil formation, 
52. 
Pine, on dry-farms, 253. 
Pinion pine, on dry-farm lands, 
305. 
Plant, see also Crops; in soil for- 
mation, 55; carbon in plants, 171; 
proportions of plant parts, 258; 
movement of water through 
plant, 170; vigor of plant and 
transpiration, 179; effect of age 
transpiration, 177. 
Plant-foods, enumeration of, 169; 
total and available, 282; in arid 
and humid soils, 67, 68; how 
they enter plant, 168; move- 
ment through plant, 170; effect 
on transpiration, 177, 180. 
INDEX 
Planting, thick planting and evap- 
oration, 151. 
Plow, for dry-farming, 305-309; 
moldboard type, 306; disk type, 
307; subsoiler, 309; need of better 
knowledge for dry-farming, 309. 
Plowing, the dry-farm, 413; effect 
on transpiration, 186; diminishes 
evaporation, 138; as practiced in 
various states, 195; deep and fall 
plowing in all dry-farm districts, 
194; depth of plowing in arid and 
humid soils, 126; deep plowing 
in arid soils, 62; deep plowing 
defined, 126; deep plowing for 
water storage, 125-126; reasons 
for fall plowing, 127; fall plowing 
for water storage, 126, 127; fall 
plowing prevents evaporation, 
127; fertility effects of fall plow- 
ing, 127; time for fall plowing, 
128; disking after fall plowing, 
129; time for spring plowing, 
128; in spring prevents evapo- 
ration, 159; in spring of fall- 
plowed land, 159; in spring after 
fall plowing, 129; disking fall- 
plowed land in spring, 159; and 
fallowing, 193; rough land 
eatches moisture, 128; to in- 
crease pore-space, 102; to reduce 
run-off, 98; wet soils, 101, 128; 
disadvantages of steam plowing, 
323. 
Plums, on dry-farm, 252, 253. 
Pod-bearing crops, 249. * 
Poltava Station, 299, 370. 
Pore-space, of soils, 101; of gypsum 
soils, 102. 
Potash, in soils, 69. 
Potatoes, 254; depth of roots of, 
88; mechanical planters, 320; 
pounds water for one pound, 15; 
variations in composition, 268; 
water and yield, 346. 
Powell, Major J. W., on early dry- 
farming, 355. 
