390 



INDEX 



Home mixing of fertilizer, 210 



materials not to mix, 211 

 mixing rules, 210 



Hornblende, defined, 40 



Humid climate, denned, 4 



Humus, denned, 12 



Hydrated lime, 238, 244 



Hydrogen, defined, 30, 33 



Ice, a weathering agent, 6 



the Ice Age, 18 

 Igneous rocks, defined, 39 

 Illinois grain vs. stock farming test, 346, 347 

 Infertility, defined, 80 



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 



laboratory 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, 56 



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 



Lacustrine 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, agricultural, 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 in soil, 229 



to apply, 245 



often to apply, 247 



to determine good, 245 

 hydrated lime, 238, 244 

 kinds of agricultural, 238 

 laboratory exercises 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, 233 



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 



