4 BULLETIN- 441, U. S, DEPARTMENT OF AGETCULTUEE. 



Table I shows that whe^t w^^' reduced m yield each year by the 

 manganese, the decrease varymg from 480 to 1,440 pounds per acre. 

 With rye, the yield was increased in 1909, 1911, and 1912, and was 

 decreased in 1908 and 1910. With com, there was a decrease each 

 year except 1907, when the yield of stover was larger. The gTowth 

 of cowpeas was also decreased, this decrease varying from 160 pounds 

 per acre in 1912 to 2,240 poimds in 1908. Potatoes were hkewise 

 aifected, there being a smaller yield m the manganese plat each year 

 except in 1909, when there was an increase over the check plat of 

 40 bushels per acre. 



Acidity tests of the various plats were made in 1912. The results 

 of these determmations show that the manganese tests were made 

 under acid conditions. 



The lime-requirement determinations were made by means of the 

 Veitch method.^ Table II shows the amiount of lime required 

 according to this method for each plat to produce a neutral condition 

 in the soil. The soil in each plat required approximately a ton of 

 lime per acre. Where wheat was grown, the manganese and the 

 untreated plats had the same hme requirement. Where rye, com, 

 and cowpeas were grown, the manganese plats had a higher lime re- 

 qairement than the untreated plats. With rye, the manganese plat 

 required 2,492 pounds and the untreated plat 2,136 pounds of lune 

 per acre. With com, the manganese plat required 2,492 pounds and 

 the untreated plat 1,780 pounds per acre. With cowpeas, the man- 

 ganese plat required 2,492 pounds and the untreated plat 2,136 

 pounds per acre. Where potatoes were grown, the untreated plat 

 had a greater lime requirement than the manganese plat, the man- 

 ganese plat requirmg 2,451 pounds of lime per acre and the untreated 

 plat 2,743 pounds. 



Table II. — ■Liine{CaCO^) requirement per acre of the various plats, to a depth of 6 inches. 



Plats. 



Wheat. 



Rye. 



Corn. 



Cowpeas. 



Potatoes. 



TrRatPfi with Tnn.Tip-aTiPSft 



Pounds. 

 1,780 

 1,780 



Pounds. 

 2,492 

 2,136 



Pounds. 

 2,492 



1,780 



Pounds. 

 2,492 

 2,136 



Pounds. 

 2,451 



Untreated 



2,743 







1 Veitch, r. P. The estimation of soil acidity and the lime requirements of soils. In Jour. Amer. Chem. 

 Soc, V. 24, no. 11, p. 1120-1128. 1902. 



Comparison of methods for the estimation of soil acidity. In Jour. Amer. Chem. Soc, v. 26, 



no. 6, p. 637-662. 1904. 



