SOILS AND FERTILIZERS 475 



good a mechanical condition as those made by the leading manu- 

 facturers. 



This method of purchasing also possesses the further advantage 

 of enabling the farmer to apply just the kind and form of ingredient 

 that he has found by experience or experiment to be best adapted to 

 his soil and crop. Besides, he knows positively, particularly in case 

 of the element nitrogen, whether it is in the form of nitrate, am- 

 monia, or organic matter, and whether the organic nitrogen is con- 

 tained in substances that are likely to decay quickly, as blood, cotton- 

 seed meal, etc., or in such insoluble and slowly acting substances as 

 ground leather, horn, etc. In mixtures the kind of organic nitrog- 

 enous substances used can not be definitely shown by a chemical 

 analysis. 



Whether or not it is profitable to prepare home mixtures of 

 fertilizers depends upon conditions. The question can be answered 

 by any one who desires by calculating the cost of the unmixed ma- 

 terials and after allowing for the cost of mixing, compare the results 

 with the price at which the mixed fertilizers could be purchased. 

 The quantity of each ingredient to be used in making the mixture 

 must, of course, be known, and the cost of the ingredients, including 

 freight charges, must also be ascertained. It may be said further in 

 favor of home mixtures that the grade of material used is known. 

 It is also easy to vary the mixture for the purpose of testing the effect 

 of different combinations upon the soil. 



The probable reason that more farmers do not buy the chemi- 

 cals and mix their fertilizer according to the needs of their farms 

 and the crops to be grown is that they do not know how to combine 

 the chemicals in order to produce the required mixture. This need 

 not give one any difficulty if a little study be given the subject. If it 

 has been found that good results have been secured with a certain 

 mixed fertilizer, then those chemicals should be purchased and 

 mixed which will give a similar proportion of plant-food. 



The mixing of fertilizers on the farm can be done very satis- 

 factorily by emptying the raw materials on a tight floor of wood or 

 concrete ; or if more convenient it may be done on a hard dirt floor 

 under a shed or outhouse. It is better not to empty over 400 to 600 

 pounds at one time, as it can be more readily and thoroughly mixed 

 in small quantities. The mixing can be done with hoes and shovels 

 by turning over two or three times and continuing this process until 

 the desired quantity is ready for use. This method of home mixing 

 is very desirable wnere the farmer wishes to leave out any element 

 or in any way change the proportion to better suit special conditions. 



The only tools necessary for home-mixing are a square-pointed 

 shovel, a broom, an ordinary 2x6 sand screen with three meshes 

 to the inch, a wooden tamper and a pair of platform scales, the 

 latter are not absolutely necessary when mixing large quantities be- 

 cause the materials come in bags of a known and fixed weight. Put 

 the materials together in a pile on a clean barn floor, placing the 

 most bulky ingredient on the bottom and the least bulky on top. 

 Turn over with the shovel into cone-shaped piles about three times, 



