(e) Nitrate of Soda 



Nitrate of soda, as is well understood, is one of the most valuable nitrogen 

 fertilizers. Some authorities assert that where this material is used as a 

 source of nitrogen the use of potash as a fertilizer is rendered either entirely 

 or in part unnecessary. The authority for this statement is so good that it 

 does not seem possible to doubt that nitrate of soda is useful in the direc- 

 tion indicated, but that the employment of this material will render potash 

 fertilization unnecessary is not supported by the experimental work of this 

 station. 



(f) Acid Phosphate 



Good authorities assert that acid phosphate favors the activity of bene- 

 ficial soil organisms, that it indirectly favors the assimilation of atmos- 

 pheric nitrogen, and that as a result of its use the availability of soil potash 

 is increased. The latter effect is supposed to be due to the calcium sulfate 

 (land plaster) which acid phosphate contains. Experimental work at this 

 station shows clearly that on our medium soils the effect of acid phosphate 

 upon potash availability is by no means great. 



In conclusion upon this topic, it is urged that while it is not believed 

 that the use of the materials under consideration can be made to entirely 

 take the place of potash fertilization, it is nevertheless worthy of considera- 

 tion. The cheaper of these materials should undoubtedly be more freely 

 used than under ordinary conditions. 



3. More Careful Conservation and Utilization of All Home Resources. 



Animal Manures. These, of course, should be carefully saved and 

 used at all times. They should be so handled as to prevent undue heating 

 in loose piles for this means loss of ammonia. Especially at this time when 

 potash from other sources cannot be obtained at reasonable cost, all loss of 

 urine should be prevented, for this contains about four- fifths of the total 

 potash of the excrements as well as a large amount of nitrogen. Exposure 

 to rains in piles or small heaps means the washing out of soluble consti- 

 tuents — chiefly nitrogen and potash. The use of acid phosphate scattered 

 over the manure at the rate of about a pound per day for each horse or cow 

 may sometimes be advisable as a means of preventing loss of ammonia. 



Attention is called to the fact that the earth beneath leaky stable floors 

 absorbs and retains most of the potash from the urine which passes through, 

 and if the stable has been long used, this earth may be richly worth re- 

 moval. The same may be true of the surface earth of open yards or pens in 

 which manure has accumulated for some time. It may be worth while to 

 remove a few inches, or at least to scrape them much closer than usual. 

 The same may be true of the earth below manure heaps and composts. 



Well-saved manure carries per ton about the following amounts of the 

 chief plant-food constituents: 



Nitrogen 10 pounds 



Phosphoric acid 7 " 



Potash 10 " 



The weight of a cord varies from about two to three tons. An ordinary 

 two-horse cartload of cow manure weighs about a ton. Since manure must 

 apparently in most cases be the chief source of potash for next season, it is 

 apparent that when possible some manure should be applied to all land 

 which is to be planted to hoed crops unless it is known that the soil -is 

 already well supplied with that element. Moderate manuring and some 



