460 



Journal of Agricultural Research 



Vol. XIII, No. 9 



Table X. — Analyses 0/ soil samples from Arlington Experimental Farm, ipi§ 



No effect which may be attributed to the boron is evident from the 

 results given in Table X. It is known that in cases of excessive applica- 

 tions of manure, as in the two 40- ton applications reported above, normal 

 bacterial metabolism does not take place. This may account for the 

 lack of evidence of the influence of the boron on the nitrogen constituents 

 of the soil. No soluble boric acid and only small amounts of total boric 

 acid were found in the soil. The absence of soluble boron is in agree- 

 ment with the first year's findings. 



It is evident that there is no accumulation of boron in the upper 6 

 inches of soil following two heavy applications of borax to the soil within 

 one year. 



EFFECTS OF THREE APPLICATIONS OF MANURE CONTAINING BORON 



ON CROPS AND SOIL 



Experiments to determine the effect of three applications of boron- 

 treated manure on crops and soil were carried out on the farm of the 

 Bureau of Animal Industry at Bethesda, Md., in 1914, 1915, and 1916. 

 A plot of ground 206 feet long and 60 feet wide was selected. The experi- 

 ments were similar to those at the Arlington Experimental Farm and 

 included three successive applications of horse manure containing added 

 borax and of manure containing added colemanite to the same soil and 

 their influence on the crops grown thereon. Nine plots were used, and 

 the treated and untreated manure was applied at the rate of 16, 24, and 

 40 tons per acre. The amount of boron added is given on page 451. 

 Guards 3 feet wide separated all the plots. The distribution of the boron 

 in different parts of the crops grown on the various plots and its effect on 

 the nitrogen distribution in the soil were also studied. 



EXPERIMENTS OF THE FIRST YEAR, 1914 



On October i, 1914, kale, lettuce, and spinach seeds and onion (Allium 

 cepa) sets were planted in all the plots. Notes taken at different times 

 following the planting showed that all plots looked equally well. In 

 April, 1 91 5, it was seen that the lettuce had not survived the winter but 

 the kale, spinach, and onions were growing. No injury and no variation 

 in the growth on any of the plots were seen. It was apparent that the 



