Index. 235 



Trifolium, procumbeus, 221 



repens, 138, 183, 221 

 Tufted hair grass (see Aira) 

 Turnips, 114 



UMBELLIFER^E, 220 



Unexhausted manures, 30, 32, 45, 60, 106, 179, 190, 206, 208 



source of fertility in, 34 

 United States, yield of wheat in, 37 



soils of, 41 



Unmamired produce, 9, 14, 24, 36, 96, 112, 116, 122, 136, 144, 204, 

 207, 211, 219 



VARIATIONS in chemical composition of barley crop, 128 

 Vernal sedge (see Carex) 

 Veronica, 220 



chamsedrys, 138 



Vetchling, meadow (see Lathyrus) 

 Vicia, 221 



WEATHER, factors of, 209 



Weeds, 35, 36, 38 



Wheat, composition of, 142. 188 



crop, cause of lessened area, 62 



nitrogen removed by, 197, 200 



crops, remarkable, 63 

 White clover (see Trifolium repeus) 

 Woodrush, field (see Luzula) 



YARROW (see Achillea) 



Yellow bed straw (see Galium) 



Yellow oat grass (see Avena flavescens 



Yield of wheat, 75, 79 



Yorkshire fog (see Holcus lanatus) 



