104 



For the potatoes, as a minimum application 650 pounds per acre oi 

 the following mixture may be used : 



Fertilizer for potatoes. 



Pounds. 



Nitriate of soda 50 



Cotton-seed meal 150 



Ground bone 100 



Acid phosphate 200 



Muriate or sulphate of potash 150 



This mixture contains — nitrogen 3 per cent, phosphoric acid 8 per 

 cent, and potash 12 per cent. In this application we are guided by 

 certain other well-defined principles, chief of which are : This is usually 

 the money crop of the rotation ; we can therefore afford a more expen- 

 sive manuring. Since it grows and matures in a comparatively short 

 time, we need to furnish a reasonable excess of plant food in order that 

 the crop may be abundantly supplied even though unfavourable condi- 

 tions occur. It is a crop which is particularly benefited by potash, and 

 we must therefore provide that element in largest proportion ; and as 

 it is not an exhaustive crop, we may expect considerable increase in soil 

 fertility due to the unused residue. 



After the potatoes are removed the land, on account of the frequent 

 cultivation of the potato crop, is in fine mechanical condition essential 

 for the rapid germination and early growth of wheat. It is also well 

 supplied with plant food because of the manure applied to the previous 

 crops in excess of their needs. 



For the wheat, therefore, such home supplies of manure as are avail- 

 able may be applied after ploughing and well worked into the surface 

 soil with the addition at time of seeding of 200 pounds per acre of dis- 

 solved bone, or a mixture of 100 pounds each of ground bone and acid 

 phosphate. In spring, if the crop does not show a vigorous condition, 

 sow broadcast 100 pounds per acre of nitrate of soda. 



By this method the manuring is accomplished at a minimum expense, 

 and the phosphates which are so essential for the proper development 

 of the grain are provided, partly in an immediately available form 

 partly in a form that will gradually decay and feed the crop at later 

 stages of growth. The nitrogen is applied when the plant has greatest 

 need for it and in a form immediately available, while for potash the 

 plant depends entirely upon the accumulated soil supplies. The hay 

 crop which follows, if it consists of clover, will be able to make normal 

 growth with added supplies of phosphoric acid and potash only, which 

 may consist of a mixture of equal parts of acid phosphate and muriate 

 of potash at the minimum rate of 300 pounds per acre. 



This method of fertilizing should not be changed from year to year' 

 but followed in the succeeding rotation courses, and it will enable the 

 farmer to secure an increased yield and improvement in soil at a mini- 

 mum expense. 



The principles involved may also be applied in other lines of farming > 

 modified by character of soil, climate, and kind of crop. In market 

 gardening the amounts applied should be proportionately increased;. 



