524 



INDEX 





PAGE 



Mulching, grain fields 208 



Plow land 209 



Muriate of potash 341 



Nature, method of tillage 18 



Nematodes in the soil 391 



Nitrogen, as plant food element. . . 3 



Fixation by symbiosis 423 



Fixation without symbiosis. . . .429 



Fixing organisms 429 



Per cent in humus 123 



Transfer from nodules to plant. 425 



Nit rogen lime 330 



Free, loss from manures 377 



Nitrification 412 



Nitrification, depth to which it 



extends 41S 



Effect of aeration on 416 



Effect of organic matter on. . . .413 



Effect of sod on 417 



Nitrates in soil, affected by drain- 

 age 244 



Loss from soil 418 



Of soda, effect on structure. ... 118 



Reduction to ammonia 420 



Reduction to nitrites 420 



Nitragin 428 



Nitrites, reduction to free nitrogen420 



Nitro-bacteria 412 



Nitrobacter 413 



Nitrosococcus 412 



Nitrosomonas 412 



Nitrous ferments 413 



Nobbe, on germination and tem- 

 perature 449 



Nodules 423 



Nodules, transfer of nitrogen to 



plant 425 



Number of bacteria in soil 397 



Particles, calculation 81 



Particles in soil 81 



Nutrient salts, absorption of 286 



Selective absorption 286 



Occlusion, relation to soil absorpt'n301 

 Oily substances on soil particles 



affects capillarity 183 



Open drains, advantages and dis- 

 advantages of 250 



Construction of 250 



Conditions permitting 248 



Organic acids, use for soil analysis . 273 

 Organic constituent of soil 119 



PAGE 



Organic matter, amount in soil. . .124 



Absorptive properties 128 



Affects water capacity 153, 361 



And raw phosphates 361 



As coloring material 101 



Composition 121 



Derivation of 120 



Effect of decay on temperature 



452,464 



, Effects of on soil 129 



Effect on nitrification 413 



Effect on structure 113,361 



In relation to bacteria 361, 401 



In relation to carbon dioxide . . .361 



In relation to fertilizers 361 



In relation to soil air 433 



Loss by leaching 127 



Maintenance of in soil 131 



Nitrogenous, decomposition by 



bacteria 407 



Non-nitrogenous, decomposition 



by bacteria 404 



Properties of 126 



Sources of 120 



Used to prevent erosion 497 



Volume change 128 



Organic nitrogen in fertilizers. . . .332 



Organic soils 43 



Organisms in the soil 3S8 



In soil, effect of drainage on ... . 244 



Macro-, in the soil 388 



Micro-, in the soil 391 



Of soil, importance of tempera- 

 ture for 450 



Osmotic equilibrium in plants. . . .287 

 Outlet of underdrains, importance 



of 261 



Oxygen, as plant food element. ... 3 



Relation to soil bacteria 399 



Oxidation, a function of soil air. . .437 



Packers and crushers 4S6 



Packing of subsoil, benefits of . . . .212 

 Parkes, effect of drainage on soil 



temperature 243 



Particles of soil, constitution of . . . 69 



Number of in soil 80 



Number of calculation 81 



Of soil, mineral character 70 



Of soil, shapes 70 



Surface area of 82 



Peat, defined 121 



Formation of 41 



