456 Journal of Agricultural Research voI.xiii.no. 



Table V. — Percentage of boron in soil samples front Benton Harbor, Mich., igi^ 



Boric acid added to upper 6 inches of soil. 



Soluble 

 boron as 

 boric acid 



found. 



Total 



boron as 



boric acid 



found. 



Per cent. 



0.00176 as borax 



0.00232 as colemanite 



Control 



Per cent. 



Per cent, 

 o. 00004 

 . 00012 

 . 00003 



As in the other samples of soils analyzed, no soluble boron was present. 

 More total boric acid was found in the sample from the colemanite than 

 in the sample from the borax plot. The amount of boric acid in the 

 control soil was practically the same as found in the control plot of the 

 barley experiments at Walnut Creek, Cal. 



EFFECT OF TWO APPLICATIONS OF BORON-TREATED MxlNURE ON 



VEGETABLES 



Nine plots, each 29.7 by 40.74 feet, with 3-foot guards were used for 

 these experiments at Arlington Experimental Farm. Three of the plots 

 received manure containing added borax; three of them received similar 

 applications of manure containing added colemanite ; while the remaining 

 three plots received untreated manure. The amounts of boron added 

 to the plots are given on page 451. 



EXPERIMENTS OF THE FIRST SEASON, 1914 



Six rows of spinach (Spinacia oleracea) and six rows of kale (Brassica 

 oleracea acephala) per plot were planted on October i, 191 4. On this 

 date young cabbage {Brassica oleracea capitata) and lettuce {Lachica 

 saliva) plants, two rows each per plot, were set out. On October 9 it 

 was evident that the boron had not prevented germination, as spinach 

 and kale plants appeared above the ground on all plots. The lettuce 

 and cabbage plants were normal. On November 10 it was evident that 

 the spinach and kale plants were not as numerous on all the 24- and 40- 

 ton plots as on the 16-ton plots. No signs of burning were observed on 

 any of the plots. No injurious action of the boron was evident in the 

 early spring of 191 5. The majority of the lettuce and cabbage plants 

 did not survive the v/inter, but the spinach and kale looked normal. 



ANALYSES OF VEGETABLES AND SOIL 



On June 26, 1915, lettuce, cabbage, spinach, and kale plants, also 

 samples of the soil 6 inches deep, were taken from the different plots. 

 The results of the analyses of the vegetables are given in Table VI, and 

 the soil results in Table VII. The methods used were those described 

 on page 452. The tops of all varieties of the plants contained more boron 

 when grown on the 40-ton plots than when grown on the 16- or 24-ton 

 plots. All the roots gave negative results for boron. More boron was 



