materials such as blood or tankage, and if mixed with acid phosphate it may- 

 decrease the solubility of the phosphoric acid. It does not appear to be best 

 to use it in mixtures in excess of about 200 pounds to the ton, and if applied 

 in fairly liberal quantities by itself, it should if possible be incorporated with 

 the soil a few days before the seed is planted. 



Vegetable sources of nitrogen such as cottonseed meal and castor pomace 

 are exceptionally high in price, but it is well to remember that besides nitro- 

 gen they furnish some potash and phosphoric acid. 



Blood and tankage are good sources of nitrogen. 



For a single application to long-season crops, a combination made up of 

 about one-third each of nitrate of soda, either cyanamid or sulfate of 

 ammonia, and either cottonseed meal or tankage is likely to be satisfactory. 



2. Phosphoric Acid 



The use of fine ground rock phosphate is not recommended for general 

 application and certainly not for quick returns, and there appears to be no 

 conclusive evidence that mixing it with manure as is sometimes advised in- 

 creases its availability. 



The phosphoric acid of bone and tankage is much more available than 

 that of rock phosphates, but acid phosphate is the most quickly available 

 source of phosphoric acid and must be chiefly depended upon as a source of 

 that element for general crops. The high price at which it is now held sug- 

 gest the advisability of unusual care in its use. It should not be forgotten, 

 however, that a fairly liberal use of a fertilizer supplying soluble phosphoric 

 adid seems to promote early root development, rapid growth of the crop and 

 relatively early and perfect ripening. Because of its effect upon early root 

 development it may have an important influence on the extent to which the 

 plant is able to draw upon the soil itself for food. 



3. Potash 



It should be remembered that no complete substitute for potash is 

 known. Fine ground feldspar as a source of potash cannot be recommended 

 as the potash which it contains is not available and, so far as known, there is 

 at present no practicable method, economically speaking, of rendering potash 

 from this source accessible to the crop. 



Wood ashes in most localities seem likely to be the only material that 

 can be purchased to supply potash, but the' percentage of that element in 

 these, on account of the unusual demand, is likely to run low, and they 

 should be purchased only on guarantee. 



4. Mixed Fertilizers 



The mixed fertilizers offered in the market this year, according to the 

 announcements of a number of the more prominent manufacturers, will in- 

 clude brands showing the following variations in plant food: 



Ammonia from 1 to 6 per cent 



equivalent to 



Nitrogen " .8 " 4.95 " 



Available phosphoric acid " 8 "10 " 



Potash "0 "1 



SUGGESTIONS FOR DIFFERENT CROPS 

 1. Top-dressing Grasslands 



Where market hay relatively free from clover is desired, an application 

 furnishing nitrogen alone is probably advisable this year, since potash can- 



