NUTRIENT SOLUTIONS AND WATER CULTURES. 

 TABLK 2. Dry weight of //// ( rop of jilants. 



The following tabulation shows the increase in weight of one 

 hundred roots in each case when lime was added : 



These figures indicate that the least increase was found in the 

 sodium nitrate solution. This is explained by Table 1, which shows 

 that even when sodium nitrate was used alone the solution was 

 alkaline at the end of the experiment, and therefore the further use 

 of calcium carbonate simply acted as a stimulant to a very slight 

 extent. 



The weight of the tops, or rather of the stems grown in solutions 

 with and without lime, show no such marked difference, indicating 

 that the appearance of the stems of young wheat seedlings is not 

 always a criterion of the vigor of the plant and therefore of the 

 probable yield of the mature crop. In other words, the root system 

 may be a better indicator as to the probable success of a crop than 

 the appearance of the portion above ground. 



The effects on the root development, due to the acidity, are always 

 easily noticeable in water-culture experiments such as these, but in 

 field tests the results of applications of single fertilizers, for example, 

 potassium chlorid, potassium sulphate, ammonium chlorid, or am- 

 monium sulphate, are not necessarily apparent in so short a time, 

 due to the fact that there may be many substances in soils which 

 neutralize the acid thus formed. 



Relative effects of potassium sulphate and sulphuric acid. In 

 Plate II, figure , are shown in a similar way the comparative effects 

 of potassium sulphate and sulphuric acid. With the potassium sul- 

 phate the plants removed all of the potash, but left 57 out of a total 

 18110 Bull. 14912 2 



