MIXING FERTILIZERS ON THE FARM 91 



of the needs of the particular soil to which they are to be applied, and the 

 requirements of the crop to be grown. The latter knowledge has been gained 

 once for all for most farm crops by a scientific study of these crops, but the 

 needs of the soil must in most cases be learned by the farmer himself, either 

 from systematic field experiments, or by observation and experience. If it 

 is necessary for a farmer to use commercial fertilizers, and he is working upon 

 a kind of soil that has not already been tested, we believe it will pay him to 

 learn its needs by carrying out systematic experiments with fertilizers. The 

 experiments made at this Station amply illustrate this. It would be very 

 unprofitable to buy phosphates for use on soil like that of the Station farm, 

 but potash salts could be profitably used there on most crops. This is because 

 the soil is already rich in phosphates. But if it were deficient in phosphates, 

 as is the case with many soils in this State, it would be unprofitable to use 

 potash salts alone, and one would have to supply phosphates. It is, therefore, 

 necessary in purchasing a commercial fertilizer to consider, first, what our 

 soil needs for the crop to be raised, and then to look for the fertilizer contain- 

 ing most of these substances, in an available form, as shown by its chemical 

 analysis and guaranteed by the manufacturer, at the least cost. It is well 

 to bear in mind, also, that nitrogen compounds are the most expensive con- 

 stituents of commercial fertilizers, and if we can keep up our nitrogen supply 

 by means of clover, cow peas, or other leguminous plants, or by barnyard 

 manure, and purchase only such phosphates and potash as may be needed, we 

 will have accomplished a great saving." Here, too, is a strong argument for 

 home mixing, since it will rarely happen that we can get a ready mixed fer- 

 tilizer exactly suited to our soil and crops without buying at the same time 

 something we do not need. Bulletin No. 80 of the Vermont Station shows 

 that in the past spring (1900) the average price of mixed fertilizers was 

 $28.73, and the average value, based on the retail price of the ingredients, 

 was $18.08, another evidence of the saving to be made in home mixing. 



But the most complete investigation of the value of home mixing of fer- 

 tilizers has been made at the Ohio Agricultural Experiment Station. It is 

 claimed by the factory mixers of fertilizers that in using tankage as a source 

 of nitrogen they have a great advantage in the fact that they treat their 

 tankage with sulphuric acid to render it more soluble, and hence far better 

 than the untreated tankage used in the simple mixtures. It was shown by 

 the experiment at the Ohio Station that this causes great loss of nitrogen 

 from fall application to the wheat crop and "it follows, therefore, that if the 

 treatment of tankage with sulphuric acid serves to make its nitrogen as solu- 

 ble as that in sulphate of ammonia and this is precisely what is claimed for 

 it then such treatment is injurious and not beneficial to him who would 



