May 27, 1918 



Boron 



467 



samples taken on September 3, 191 5, tvvO months after the second addi- 

 tion of boron-manure to the soil, it is evident that the boron gradually 

 disappeared from the upper 6 inches of soil, and no cumulative action of 

 boron resulted from the three successive additions of boron-treated 

 manure to the same soil when 0.08 pound of borax or 0.095 pound of 

 colemanite was added to the bushel and the manure applied to the soil 

 at a rate of 40 tons per acre. 



Table XIII. — Nitrogen distribution and boron as boric acid in ike soil, Beikesda, Md. 

 [Sampies of soil were taken from same plots following each of the three additions of manure and boron] 



' Samples taken on June i, 1915. Manure applied in October, 1914. 



^ Samples taken on September 3, 1915. Manure last applied in June. 1915. 



3 Samples taken on June i, 1916. Manure last applied on November i, 1915. 



SECOND ANALYSES OF BORON-TREATED SOILS FROM THE SOUTH 



In order to obtain information as to the length of time that boron 

 remained in the soil, a second series of samples of soil from Orlando, 

 Fla. ; Dallas, Tex.; and New Orleans, La., were analyzed in June, 1916. 

 These soils had received applications of manure plus borax and plus 

 colemanite the year previous, and analyses of the soils for soluble boron 

 have been reported (2). The results of the analyses are given in 

 Table XIV. 



In 1 91 5 soluble boron was found in all of the Orlando and New 

 Orleans samples and in two of the Dallas soil samples. In 191 6 no 

 soluble boron was found in the samples from any of the boron-manure 

 or control plots. Only relatively small amounts of total boron were 

 found in these soils in 191 6. The samples from the boron-treated plots 

 showed the presence of only a little more boron than the controls. The 

 disappearance of the boron and the holding of the small amount present 

 in an insoluble form is a remarkable demonstration of the power of the 

 soil to absorb toxic substances and to hold them in an inactive form. 



