302 CULTURE OF FARM CROPS. 



slowly into action. Thus perfectly consistent with sound 

 theory is that which we find most successful in practice, 

 viz., that some portion of the manure should be furnished 

 in the form of superphosphate, and some in the form of 

 plain phosphate, joined with a moderate amount of am- 

 monia, which is just what bone-dust supplies. We have 

 so frequently found this system successful, that we can with 

 confidence recommend the following mixtures as highly 

 suitable for a crop of swedes : 



Superphosphate of lime, ... 2 cwt. 



, Bone dust, .... 8 bushels. 



to be mixed and drilled with ashes ; or we might vary 

 it thus : 



Superphosphate of lime, ... 2 cwt. 



Bone dust, .... 4 bushels. 



Peruvian guano, .... 1 cwt. 



The latter might more advantageously be sown broad- 

 cast, and the two former drilled with ashes. By sowing the 

 grain broadcast we do not endanger the seed, and we supply 

 nutriment for the filaments given off laterally from the roots. 



104. There are many varietits of guano much richer in 

 the phosphates than Peruvian guano, but poorer. in ammonia, 

 and these suit admirably for turnips, particularly when 

 combined with superphosphate of lime. Such are the 

 Saldanha Bay, the Patagonian, the Chilian, and other 

 varieties, more particularly the Bolivian, which is the best. 

 Although the analysis of some of these guanos very much 

 resemble that of bones, both with reference to the pro- 

 portions of ammonia, and the phosphates likewise, yet their 

 action is greater and immediate, having been passed through 

 the bodies of birds and digested. Thus we have found 

 the following succeed admirably : Superphosphate of 

 lime, 2 cwt., South American guano, containing 50 to 60 

 per cent, of phosphate of lime, 2 cwt., and this can either 

 be drilled with ashes, or by means of the water drill." 



105. The land i$ prepared for the reception of the seed 

 in one- of two modes "drilling" or "on the flat." The 

 former method is almost universally used in the northern 



