302 THE TURNIP CROP. 



ammonia is not considered to be so necessary to root as 

 it undoubtedly is to our cereal crops ; and, accordingly, 

 phosphate of lime in a partially soluble condition, as "super- 

 phosphate/' is generally used without the addition of either 

 of the other more expensive substances. This is unques- 

 tionably wrong, as although the plant from its nature and 

 habit of growth may obtain an unlimited amount of am- 

 monia from the air, it is quite certain its root powers are 

 limited in regard to potash, which only exists in the small- 

 est proportions in the soil, and yet is essential to the de- 

 velopment and healthy growth of the turnip (see analysis}, 

 and should in all cases be added, especially where no farm 

 dung (which in itself contains it) has been used. The 

 addition too of chloride of sodium (common salt), at the 

 rate of 2 to 5 cwts. per acre, would in most cases be fol- 

 lowed by increased returns, especially in the midland and 

 other districts, too distant from the sea to admit of any 

 sensible portion being carried over by the wind and the 

 rain. 1 A glance at the analysis of the turnip (p. 328) 

 will at once explain the policy of these additions to the 

 phosphate of lime. As a general rule, applicable to all 

 cases and to all artificial manures, it must be remembered 

 that efficiency is greatly influenced by their amount of 

 division and distribution through the mass of soil which 

 they are intended to benefit. The more concentrated de- 

 scriptions, as "guanos/' " superphosphates," &c., should be 

 well mixed with neutral substances, as sand, ashes, or even 

 dry soil, previous to being applied; and then the more 

 they are moved about and incorporated with the soil, the 

 greater the chances the plants have of meeting with them, 

 and the more immediate and beneficial are their effects. 

 After the sowing has been successfully accomplished, 



1 Salt has often been identified in the rain water during stormy weather at 

 distances of 40 to 50 miles from the nearest point of the shore. An immense 

 quantity, therefore, must fall on the surface of a country surrounded by sea, 

 as this is. 



