46 



TEXAS AGRICULTURAL EXPERIMENT STATION. 



PERCOLATION OF POTASH. 



One gram sulphate of potash was added to pots Nos. 4. 10, 16, 22, 

 28, 34, 40 and 46 on Octoher 15, 1910, 1911, 1912 and 1913. In addi- 

 tion, two grams were added to pots Nos. 4, 10, 16 and 22 and four 

 grams to 28, 34, 40 and 46 on March 15, 1912. The object of these 

 extra additions was to see if they increased the loss of potash. The 

 sulphate of potash used contained 50.1 per cent, potash (K 2 0). One 

 gram of sulphate of potash is equal to an application of 122 pounds 

 per acre of sulphate of potash, or 61 pounds actual potash per acre. 



The parts per million of potash in the percolates is given in Table 

 No. 19. The addition of fertilizer potash increased the potash content 

 of the percolates in several instances. 



TABLE NO. 19. 

 Parts Per Million of Potash in Percolates. 



Table No. 20 shows the potash, in mgr., percolating from the un- 

 treated soils, and those which received potash. In considering the 

 potash applied, that introduced October 15, 1910, is excluded.' The 

 maximum loss in the three years on any one soil, is 303 mg. with the 

 Norfolk sand, which is 12 per cent, of the potash added. Next comes 

 the Miller fine sandy loam, 142 mg. or 4 per cent, of that added, and 

 the Lufkin fine sandy loam, 4.5 per cent. loss. The Crawford clay lost 

 a little less than 2 per cent., -the Orangeburg fine sandy loam 2.2 per 

 cent., the Yazoo clay 0.3 per cent, and the Houston loam and Houston 

 black clay, none. 



