THE WHEAT CROP. 43 



during the fallow, Mr. Smith tells us, amount to 12s. to 

 18s. per acre. This cost would be diminished to one-half 

 or one-third, now that we have successfully harnessed 

 steam to our ploughs and cultivators. The increased 

 vigour of the plants, owing to the deep tillage and open 

 growth, shows itself in the stoutness of the straw, which 

 frequently exceeds 2 tons to the half acre, and is very 

 rarely laid. A practice of earthing up the plants with a 

 light mouldboard, which Mr. S/s system of wide cultiva- 

 tion has enabled him to apply to his wheat, no doubt as- 

 sists in maintaining the stoutness and strength of the 

 plant, as we know it does in Indian-corn and other plants 

 of the same family. 



Let us now follow the growth of the plant, whose exist- 

 ence we have traced from the parent seed up to the period 

 when, having passed through the earliest stages of its life, 

 and consumed all the food stored up for its use, it enters 

 upon an independent career, and relies upon its own 

 powers for its future support. During the growth of the 

 plant many circumstances have influence over it: the 

 principal of these are in connection with the soil in which 

 it is placed, or the atmosphere which surrounds it. Fa- 

 vourable conditions are readily recognized in the more 

 or less vigorous appearance of the plant ; in some cases, 

 however for instance, where the soil contains a large 

 proportion of available organic matter the plant starts off 

 with an appearance of growth which it is not able to sus- 

 tain in its after stages. In others, again, owing probably 

 to a deficiency of soluble silicates in the soil, 1 the straw, 

 though stout and tall, is of too herbaceous a nature, and 

 lacks the rigidity necessary to carry a full head to matu- 

 rity; and again, the produce is unsatisfactory. In both 

 these cases, the application of common salt as a top-dress- 



1 Probably the varieties of wheat requiring smaller supplies of silica might 

 be introduced with advantage on such soils. See page 88. 



