70 T. LyTTLETON LYON AND JAMES A. BizZELL 
Effect of plant growth on removal of potassium 
In spite of the fact that less potassium was removed by crops than by 
drainage water in these experiments, the total removal of potassium was 
greater from the planted than from the bare tanks. This is entirely 
contrary to the removal of calcium from the same tanks, as may be seen 
in table 23: 
TABLE 23. AvEeRAGE ANNUAL REMOVAL OF POTASSIUM FROM PLANTED AND FROM 
UNPLANTED TANKS 
(In pounds per acre) 
Potassium removed in 
Total 
Tanks Soil treatment =|—HHH-—________|_ potassium 
Drainage Grows removed 
water P 
IR ee aR erate aan hI ee eae tal Planted)... .. v2: 73.2 34.1 107.3 
VARGA Gpaian eS ener Siege Bi ees Barence eta tee 84 bu Sie 84.5 
Potassium conserved by not cropping. .... 0.0.52... 0c. c cece een eee eee 22.8 
While the growth of crops conserved the calcium in the soil, the same 
operation increased the loss of potassium. There was little difference 
in the concentration of potassium in the drainage water from the planted 
and from the bare tanks, as is shown in table 24: 
TABEE 24. Avrerace Porasstum Content oF DRAINAGE WATER FROM PLANTED AND FROM 
UNPLANTED TANKS 
Potassium in drainage water 
Soil treatment (oartelpeseallion) 
Tank 
: For Average 
Crop Lime each for crop 
tank treatment 
[Soke eto ee ae Planted. ....... Not limed...... 18.3 |% ice 
CARGO NORA NIG Planted........ imed =) eae 13.6 ee 
LA ie oe a he ull a BE NKeo gale eais-o or Not limed...... 15.5 14 0 
IU Cirroe Wea erent area cnn Ny. Barer Limed......... 1D) : 
