592 



Journal of Agricultural Research 



Vol. X. No. 12 



Colemanite, a borate of lime, is found in the deposits of Ventura County, 



Cal. Its formula is CajBeOn-sHgO. On heating, the water is driven oflf, 



and it is reduced to a grayish white powder. The calcined colemanite is 



largely, but not entirely, insoluble in cold water. It is also likely that 



part of the calcium of the colemanite when added to the soil is precipitated 



as carbonate, and the boron in the compound thus acted upon is rendered 



soluble. 



EFFECT OF THE BORON ON THE WHEAT 



The wheat was planted each year in October a few days after the 

 manure had been applied to the plots, and the growth was observed 

 throughout the year. The crops were harvested the next June. Soil, 

 straw, and grain samples were taken at the time of harvest for chemical 

 analyses. The first year there was considerable yellowing of the young 

 wheat plants in the borax plot, commencing in November and extending 

 to the growing period the next spring, when it disappeared. This 

 yellowing was not noticed the last two years when the amounts of boron 

 added to the manure were reduced to amounts sufficient to act as a 

 larvicide. There were no differences in the stand or appearance of the 

 wheat on either the borax, colemanite, or manured control plots in 191 5 

 or 1916. Each year the unmanured control showed the poorest stand. 

 The yields of straw and grain from all the plots are given in Table I. 



Table I. — Yield of wheat at Arlington, Va.,for three years, i gi 4-1 gi6, from same plots 

 {^^ acre) , fertilized annually with m,anure treated with borax and colemanite 



Treatment. 



Manure and borax 



Manure and colemanite . 



Manured control 



Unmanured control 



Yield (pounds). 



Straw. Grain 



204 



234 

 174 



104 



116 

 100 



Straw. Grain. 



159 



152 

 173 

 158 



99 

 103 



78 



1916 



Straw. Grain 



2»4 

 240 

 204 

 192 



79 

 a 68 



72 

 77 



a These shocks were badly eaten by rats. 

 YIELDS OF STRAW AND GRAIN 



The results in Table I show that the largest yield of grain was from 

 the manured control plot, with the exception of 191 6, when the borax 

 plot shov^red the largest yield. The straw >neld for 191 6 was also highest 

 on the borax plot, while the 1914 and 191 5 straw yields were highest on 

 the manured control. There was some loss from the colemanite plot 

 in 1 916 as rats ate part of the grain while it was standing in the field 

 after cutting. A gradual reduction in the yield of grain each year from 

 all plots is noticed. During 191 6 there was a marked tendency toward 

 the production of straw at the expense of grain, the ratios of straw to 

 grain being 2 to i or under for 1914 and 1915, while it was 2.5 to 3 to i 



