FERTILIZERS. 



709 



Investigations on the foraging powers of some agricultural 

 plants for phosphoric acid, W. Balentine (Maine Sta. Rpt. 1893, 

 yp. 13-25, 2)ls. 21). — Tlie comparative capacity of wheat, barley, corn, 

 beans, peas, potatoes, and turnips to utilize the phosphoric acid of 

 insoluble phosphates (South Carolina rock) was tested as follows: For 

 each kind of plant 9 wooden boxes 15 in. square and 12 in. deep, con- 

 taining 120 lbs. of fine sand,^ were used in 3 sets of 3 boxes each, fertil- 

 ized as follows: Set I, 8.5 gm. nitrate of soda (1.3G gin. nitrogen), 2.6 

 gni, muriate of potash (1.30 gm. potash); Set 11,8.5 gm. nitrate of soda 

 (1.3G gm. nitrogen), 2.(\ gm. muriate of potash (1.3G gm. potash), 17 gm. 

 South Carolina rock (3.90 gm. insoluble phosphoric acid and 0.39 gm. 

 citrate soluble phosphoric acid); Set III, 8.5 gm. nitrate of soda (1.30 

 gm. nitrogen), 2.6 gm. niuriixte of potash (1.30 gm. potash), 28.5 gm. 

 acidulated South Carolina rock (3.31 gm. soluble phosphoric acid, 0.50 

 citrate soluble phosphoric acid, and 0.02 gm. insoluble phosphoric acid). 



The boxes were given proper care, and the crops were harvested at 

 maturity; photograplis, from which the plates in the article were made, 

 being taken just before harvesting. The yields obtained were as fol- 

 lows: 



Yields of dry matter hy different crops. 



Wheat., 

 iiarley. . 



Corn 



Beau 8 .. 



Peas 



Potatoes 

 Turuips 



Yield of dry matter. 



Set I.-lfo 

 phosphate. 



Grains. 



76.9 



201.5 



39.5 



15.7 



112.7 



113.3 



154.4 



Set II.— 

 Insoluble 

 phosphate. 



Grams. 

 148.6 

 294.9 

 103.3 

 17.4 

 190.7 

 114.6 

 304.1 



Set III.— 



Soluble 

 phosphate. 



Grams. 

 296.3 



508.1 

 291.0 

 69.8 

 22S. 6 

 223. 6 

 270.4 



"While it may not be desirable to draw-defiuite conclusions from so small an amount 

 of data as is furnished by the above-described e.Kperiments, there are some points 

 which under the conditions of these experiments the results appear to bring out 

 sharply. 



"(1) Different crops showed a decided difference in their powers of obtaining 

 phosphoric acid from crude, finely ground South Carolina rock. Wheat, barley, 

 corn, peas, and turnips apparently appropriated the insoluble phosphoric acid from 

 this source Avith greater or less ease, while beans and potatoes derived no benefit 

 from it. 



'•' (2) The greatest practical advantage derived from the use of finely ground South 

 Carolina rock was with the turuip.s. With this crop a larger weight of dry matter 

 and also a larger weight of fresh roots was obtained with insoluble x)hosi>horic acid 

 from the finely ground South Carolina rock than with an equal amount of soluble 

 phosphoric acid from acidulated South Carolina rock. 



" (3) The indications i)oint to a profitable use of finely ground South Carolina rock 

 as a manure for barley and peas as well as turnips." 



' Containing 0.096 per cent of potash and 0.012 per cent of phosphoric acid. 



