390 



INDEX 



Home mixing of fertilizer, 210 



materials not to mix, 211 

 mixing rules, 210 



Hornblende, defined, 40 



Humid climate, defined, 4 



Humus, defined, 12 



Hydrated lime, 238, 244 



Hydrogen, defined, 30, 33 



Ice, a weathering agent, 6 



the Ice Age, 18 

 Igneous rocks, defined, 39 

 lUmois grain vs. stock farming test, 346, 347 

 Infertility, defined, SO 



causes of, 85 



diagnosing, 86 



toxin theory of, 261 

 Inoculation, defined, 182 



a fertility factor, 182, 356 



fails on acid soil, 232 



field studies on, 185 



for better crops, 182 



home projects on, 185 



how often, 184 



l0.boratory exercises on, 185 



methods of, 182 



when succeeds on acid soil, 184, 232 

 Intertillage, 135, 161, 163 

 Iron, defined, 30, 31 



function of, in plants, 50 



rust, defined, 30, 31 

 Irrigation, affected by soil erosion, 284 



an art of antiquity, 132 



defined, 126 



farming under, 131 



how water is applied, 128 

 secured, 128 



methods of, 129, 130 



much land needs, 131 



objects of, 127 



profits in irrigation farming, 131 



Jointers, 141 



adjustments of, 141 



Kafir corn, rotation for, 277, 280 



where grown, 277 

 Kainit, fertilizer, 202, 203 



Labor income, defined, 370 



Laboratory instructions, 4 



Lactistrine soil, defined, 15 



origin and value of, 21 



Land clearing, on marsh, 295 

 on steep slopes, 285 

 drainage. (See Drainage) 

 rental, defined, 370 



Land-plaster. (See Gypsum) 



Landslides, defined, 286 



Lateral (tile), defined, 121 



Law of diminishing returns, 374 

 the minimum, 373 



Leaching of manure, 350 



of nitrogen from soil, 349 



Legumes, compared with non-legumes, 178 

 for dry-land farming, 277 

 for green manuring, 191-193 

 for North Atlantic States, 278 

 for North Central States, 275 

 for Pacific States, 280 

 for South Atlantic States, 278 

 for South Central States, 279 

 how they improve soils, 180 

 nitrogen gathered by, 178, 180 

 nodules on, 176-183 

 to solve nitrogen problem, 197 



Light and crop growth, 77, 78 

 "Light" soil, defined, 15 

 Limate, defined, 244 

 Lime, agiicultural, defined, 229 



amount to apply, 245 



as toxin destroyer, 261 



carbonate of, defined, 41 



carbonates, forms of, 238 



comparative value of, 244 



conserved by cropping, 247 



defined, 30, 34 



for clay soils, 243, 245, 323 



for improving tilth, 323 



for marsh soils, 245, 291 



for pastures, 247 



for quick results, 245 



for root zone, 248 



for sandy soils, 245, 312 



from beet sugar factories, 243, 250 



how it acts m soil, 229 

 to apply, 245 

 often to apply, 247 

 to determine good, 245 



hydrated lime, 238, 244 



kinds of agricultural, 238 



laboratory exeicises on, 252 



lump or burnt, 243 



misuse of, 249 



mixing with manure, 219 

 fertilizers, 211 



soil toxins relations, 262 



spreader, 246 



testing soil for need of, 232, 358, 362, 

 364 



too much may prove harmful, 262 



use and misuse of, 249 



waste, 243 

 Liming, alfalfa response to, 232, 233 



beneficial in green manuring, 231 



benefits of, 229 



best material for, 244 



better than manure, 231 



clay soils, 243, 245, 323 



club root in relation to, 233 



crops benefited by, 232, 2S3 

 injured by, 233 



deep plowing no substitute for, 248 



defined, 229 



fertility regulated by, 250 



for all crops 233 



for quick results, 245 



for tilth improvement, 323 



frequency of, 247 



home projects on, 253 



improves acid soils, 229 » 



labor saved through, 231 



land-plaster for, 244 



marsh soils, 245, 301 



only one of fertility factors, 250 



pastures', 247 



peas respond to, 233 



peat soils, 245, 301 



poor soils, 245 



potato scab in relation to, 233 



problems solved by rotation, 267 



relation to soil toxins, 262 



remedy for club root, 233 



restoring worn-out soils, 250 



sandy soils, 245, 312 



to reduce total acidity, 249 



when most profitable, 231 

 Limestone, acid soil possible on, 242 



coarse, is slow acting, 240 



defined, 39 



dolomitic, 238 



