INDEX 



349 



Natrolite, 22 

 Natural manures, 202 



,, productiveness, 163 

 Nepheline, 22 

 Nitragin, 148 

 Nitrates, formation of, 103, 152 



,, in drainage, 101 

 Nitrate of lime, 269 



potash, 201, 269 

 ,, ,, soda, adulteration of, 



263 

 ,, ,, ,, application of, 



264 



,, ,, ,, compared with 

 sulph. of am., 

 265 



,, ,, ,, deposits of, 259 

 ,, ,, ,, extraction of, 



260 



,, ,, ,, exhaustive 



effects of, 266 



,, ,, ,, manurial value 



of, 263 



Nitric acid in air, 12 

 ,, ,, in rain, 16 

 ,, ,, in soil, 103, 156 

 ,, ferments, 156 

 Nitrification, 153 

 Nitrites, 159 

 Nitrogen, atmospheric, 12 



, , in animal excreta, 309 

 ,, ,, crops, 169, 193 

 ,, ,, humus, 110 

 ,, ,, manures, 180. See 

 also Various manures. 

 ,, ,, plants, 5 

 ,, ,, rain, 16 



,, soils, 14, 161 

 ,, fixation of, 144 *v^^j 



loss of, 101 



,, retained by animals, 

 167, 308 



Nitrogenous guanos, 295 



,, manures, 249 



Nitrolim, 271 

 Nitrous acid, 153, 161 

 Nitrous ferment, 156 

 Nodules on roots, 143 

 Number of particles in soil, 51 



OATS, composition of, 169 



,, manures for, 195 

 Oat straw, 312 

 Odour of soils, 84 

 Olivine, 21 



Onions, manure for, 199, 285 

 Oolitic limestone, 37 

 Optimum, amount of water, 62 

 Organic matter, destruction of, 



,, ,, estimation of , ttl 



,, ,, formation of, 40 



,, in air, 10" 



,, ,, in plants, "> 



,, ,, in soils, 108 



,, rocks, 28 



Organisms in soil, 137 



Origin of soils, 18 



Orthoclase, 21, 129, 277 



Osborne's method, 92 



Ossein, 239 



Oxidation, 11 



,, in soil, 131 



Oxygen, atmospheric, 11 



,, absorption of, by plants, 



5 



,, evolved by plants, 15 

 ,, in soil gases, 135 



PAN formation, 33, 113, 115 

 Parasitic fungi, 138, 139 

 Parsley, manure for, 199 



