

754 



INDEX 



Disk plow, 666. 



Disking to hold moisture, 714. 



Ditching machines, 649. 



Dolomite, 6, 9. 



Drag as soil pulverizer, 680. 



Drain till, quality, 640. 



Drainage and absorption, 368. 



Drainage and denitrification, 456. 



coefficient, 651. 



effects on soil, 630. 



effect on soil ventilation, 477, 488. 

 ' effect on soil bacteria, 484. 



extent of need, 628. 



efficiency of fertilizer, 568. 



formation of humus, 152. 



history of development 



of irrigated and alkali land, 659. 



of land, indications of need, 627. 



methods, 634. 



muck and peat soil, 658. 



promoted by soil organisms, 422. 



reclamation of alkali land, 400. 



relation to green manure practice, 

 624. 



relation to colloids, 166. 



run-off checked, 269. 



systems, arrangement, 643. 



toxic materials eliminated, 137. 



use of explosives, 661. 



tile drains, 639. 



vertical, 660. 

 Drainage water at Bromberg, 370. 

 Drainage water, composition, 369, 351. 

 Drainage water, relation of phosphates 



and carbon dioxide, 482. 

 Drains, protection of joints, 642. 

 Dried blood, 507. 

 Drift defined, 52. 

 Drought-resistant crops, 715. 

 Dry-farming practices, 713. 



principles, 712. 



drought-resistant crops, 715. 



soils best suited for, 716. 



extent, 717. 

 Drying and wetting, effect on granula- 

 tion, 187. 

 Dust mulch, 272. 



Dust mulch under irrigation, 705, 710. 

 Duty of water in irrigation, 708. 

 Dynamite, drainage by means of, 661. 



Earthworms, action on soil, 19. 

 Earthworms and productiveness, 422. 

 Effective diameter of soil particles, 122. 

 Effective surface of soil, 125. 

 Effects of organic matter on soil, 150. 



Electrical production of nitrogen f.r 



tUtor, 

 Elements of plant-food, 3. 

 Enzymotic action of bacteria, 129. 

 Enzymes, effect on plant-food, 438. 

 Enzymes in roots, 407 

 Epidote, 9. 

 Kn.sion, agencies causing, 14. 



ctTcct of dramas 



in ditches, limits of Krade, 636. 



ice as agen< 



in irrigation canals, 694. 



rateot. in U.B., 14. 



wind action, l~>. 

 Eskers, 50. 

 Evaporation and alkali, 282. 



and temperature. 314. 



and wind movement, 285. 



at Kotham.-ted. 871. 



from plants, 27<>. 



prevented by, 272. 



rainfall lost by, 271. 

 •i from animals, 577. 

 Exhaustion of soil, 410. 

 Expansion of minerals by heat, 16. 

 Explosives, drainage by means of, 661. 



Factors for plant growth, 3. 



Factory-mixed fertilizer, 563. 



Fall plowing, relation to dry-farming, 



713. 

 Fall and spring plowing, 283. 

 Farm manures, 577. 

 Farm manure, waste, 597. 

 Fats in soil. 127. 

 Fats, effect on capillarity, 211. 

 Feeding power of plants, 414. 

 Feldspar, as potash fertilizer, 524. 

 Feldspar in soil separates, 101. 

 F erm e nt ation, effect on phosphates, 520. 

 Fermentation of manure, 591. 

 Ferrie phosphate availability, 337. 

 Fertilizers, 489. 

 Fertilizers and acidity, 381. 



amounts to use, 572. 



application of, 570. 



brands, 555. 



catalytic, 530. 



commercial value, 560. 



commercial, extent of use, 492. 



effect on toxic material, 137. 



factors in efficiency, 568. 



for special crops, 571. 



grades of, 562. 



home mixing, 563. 



incompatible material, 565. 



