INDEX 



389 



Fertilizers, in general, 205 

 m maintaining fertility, 206 

 laboratory exei cises on, 223, 224 

 lasting effects of, 213 

 low grade vs, high, 210 

 most profitable, 371 

 need of, determined by chemical analy- 

 sis of soil, 355-358 

 examining soil conditions, 355, 



356 

 fertilizer tests in field, 67, 364- 



368 

 pot tests, 204, 298, 360 

 soil and crop needs, 204, 208 

 pot tests for, 204, 298, 360 

 how to make, 223 

 profits determine use of, 207, 369 



from, how to compute, 372 

 rules for use of, 210 

 soil and crop determine need of, 208 

 testing in the field, 360-3GS 



importance of, 67, 68 

 in pots, 204, 298, 360 

 how to do, 223 

 not fully rehable, 204, 360 

 units, defined, 207 

 use of, determined by profits, 207, 369 



by economic laws, 373 

 valueless without decay, 173 

 when fail, 205 



most profitable, 371, 375 

 Fertilizing elements, defined, 33 



account with, m farming, 347-353 

 balance sheet of, for a grain rota- 

 tion, 348 

 on dairy farms, 348, 353 

 conserved by crop rotation, 267 

 exchange of, in farming, 350-353 

 gained from purchased feeds, 350- 



in feeds, 383 



lose and gain of, m farming, 349, 



350 

 lost by soil erosion, 283 



in feeding transaction, 349, 350 

 regained in manure, 350 

 Field tests, 67, ISS, 189, 200, 201, 204, 206- 



208, 303, 360 

 Fine sandy loam, defined, 14 

 Fire-fanging of manure, 218 

 Flax, elements removed by, 62 



crop rotation for, 276 

 Floating bogs, 16 

 Flooding (irrigation), 129 

 Food manufactured in plants, 37, 50 

 production per acre, 343 



as grain vs. as meat, 343 

 Frost, effect of, on rocks, 6 



on marsh lands, 302-303 

 Fruit, elements removed by, 69 

 Fruition period, 56 

 Furrow irrigation, 130 



Garden crops and liming, 233 

 Gases as weathering agents, 6 

 Germination (period), 47 



contact with soil, a factor, 49 



critical, 47 



fertilizers affecting, 49 



laboratory exercises on, 56 



moisture in relation to, 49 



requirements and conditions for, 48 



salts in relation to, 49 



temperature in relation to, 49 



water in relation to, 49 



Glacial soU, defined, 15 



origin of, 18 



quality of, 21 

 Glaciers, effects of, 19-21 



story of the, 18 

 Good farming, 381 

 Grade lath, use of, 118 



line, illustrated, 119 

 Gradient, defined, 117 

 Grain drills, 156-158 



for sand farming, 315 

 farming, defined, 343 



for densely populated countries, 

 343 



has led to soil depletion, 344 



importance of, 343 



maintaining fertility in, 347 



revised, 344 



stock and, compared, 346 

 on potato land, 153 

 Grains, lodging of, 64 

 Granite, defined, 39 



soil from, 42 

 Grass on clay soils, 325 



on sands, 316 

 Green manuring, defined, 190 



an old practice, 191 



benefits of, 190, 191, 194 



best time for, 193 



crops for, 192 



cover crops for, 190 



cultivation important in, 194- 



feeding the crop vs , 195 



fertilizer relations, 209 



for clay soils, 324 



for cultivated crops, 194 



for depleted silt loams, 326 



for sands, 310 



for soil improvement, 194 



hints on, 195 



in relation to liming, 231 



importance of, in South, 193 



legumes best for, 190 



plowing under the crop, 193 



precautions in, 193 



to maintain organic matter, 191 



Varro on, 191, 192 



vs. fertilizers, 191 



weeds for, 194 

 Greensand, 243 

 Gridiron system of tiling, 122 

 Ground bone fertilizer, 197, 198 



water-table, defined, 113 

 Growing period of plants, 49 



activities in, 50 



conditions and requirements in, 

 50,51 

 Gully erosion, defined, 286 

 Gypsum, defined, 40 

 for alkali soils, 259 

 for conserving manure, 218 

 for liming, 244 



Hardpan, defined, 124 



Harmful agents in soil, 255-262, 356 



Harrows, 151-154 



Harrovv'ing, 151 



Heat and cold, effects of, 6 



Heavy soil, defined, 14 



Hematite, defined, 40 



Hemp, elements removed by, 62 



response to liming, 233 



soil for, 68 

 Herringbone system of tiling, 122 

 Hoe drill, 158 



