468 



Journal of Agricultural Research 



Vol. XII r. No. 9 



Table XIV. — Percentage of total and soluble boron, nitrogen, and nitrates found in 

 samples of soil frovi Orlando, Fla.; Dallas, Tex.; and New Orleans, La. 



Soils analyzed. 



Orlando, Fla.: 



Borax plot ^ 



Control plot 



Dallas, Tex. : 



Borax plot (light)^. . 



Borax plot (heavy)^ 



Control plot 



New Orleans, La. : 



Borax plot ^ 



Control plot 



Soluble 

 boron as 

 boric acid. 



Per cent. 

 O 

 O 



Total 



boron as 



boric acid. 



Per cent. 



O. 00003 



. 00002 



. 0000 1 

 . 0000 1 



000040 

 000024 



Total 

 nitrogen. 



Per cent. 



0.056 



.056 



.208' 

 .295 

 •253 



.084 

 . 070 



Nitrogen 

 as nitrates. 



Per cent. 

 o. 00572 

 .00777 



. 00667 

 . 00805 

 . 00800 



. 00084 

 . 00090 



' 0.7S pound of borax added per S bushels of manure; manure applied at 16-ton jate. 

 2 1.25 pounds of borax added per 3 bushels of manure; manure applied at 16-ton rale. 



SUMMARY 



The influence of single applications of horse manure containing borax 

 or colemanite added at the respective rates of 0.08 and 0.095 pound to 

 the bushel and applied to the soil at the rate of 16 tons per acre was 

 tested on peach trees at Acampo, Cal., on barley at Walnut Creek, Cal., 

 and on wheat at Benton Harbor, Mich. The upper 6 inches of soil on 

 the borax-treated plots were calculated to have contained 0.00176 per 

 cent of boric acid and that on the colemanite plots 0.00232 per cent. 



No influence on the growth or yield of wheat or barley was observed, 

 yet the boron seemed to have a beneficial effect on peach trees. There 

 was no soluble boron and but little total boron in any of the soil samples 

 from the three different localities. 



Experiments were conducted at Arlington, Va., and Bethesda, Md., in 

 which the horse manure treated with borax and colemanite was applied 

 as noted above, but at three different rates per acre — that is, 16, 24, and 

 40 tons. The tests at the Arlington Experimental Farm extended over 

 two seasons and at Bethesda over three seasons. The soil was calculated 

 to have contained in the upper 6 inches when borax-manure was applied 

 at the 16, 24, and 40 ton rates, 0.00176, 0.00264, and 0.0044 per cent of 

 boric acid, respectively, and 0.00232, 0.00348, and 0.0058 per cent 

 respectively, when colemanite was applied. 



The first season at Bethesda 0.0044 P^^ cent of boric acid as borax and 

 0.0058 per cent as colemanite caused no injury to lettuce, spinach, kale, 

 or onions. These percentages of boric acid the first season at the Arling- 

 ton farm caused a reduction in crop vvdth lettuce, spinach, kale, and 

 cabbage. 



At Arlington 0.00264 per cent of boric acid as borax and 0.00348 per 

 cent as colemanite reduced the yield of spinach and kale by preventing 

 germination. The difference in the action of the same percentages of 



