920 



eac!i cyliiul;»r. Sulphate of iron in aqueous solution was added to 8 

 of the cylinders in amounts ranging from 1 to 200 grams. The two 

 others received no iron. Oats was the only crop which responded 

 favorably to the addition of iron sulphate, the other plants being more 

 or less injured. The relative sensitiveness of the cereals to iron sul- 

 phate was in the following order : Wheat, rye, barley, oats. Where 

 the iron was injurious its effect was greater on the fruit than on the 

 plant itself. No kernels were formed where 200 grams of sulphate 

 were used, except in the case of oats, where a few were formed. 

 The practical api)lication of the result is in the use of manurial refuse 

 containing sulphate of iron, and in the selection of crops for land which 

 contains iron salts. The results are in the same line as the observations 

 of practice, that oats are better fitted for iron soils than any other 

 cereals or grasses. 

 The experiments are to be continued another year with other plants. 



A new method for determining the fertilizer requirements of 

 soils, A. Helmkauipf { HdKnon'rsvhc Landu. Forsdr. Ztij.. J>!il, ji. 

 683; abs. in Ctntralhl. f. (U/r. Chem., 20, pp. 82ii-fi28). — Tlie author gives 

 a i)reliminary report of the experiments made at the suggestion of Pro- 

 fessor liiebsiher at the Gottingen Agricultural Institute. The object 

 of these \vastod<'t»'rmiii«' indirectly l)y means of plant analysis, in a way 

 similar to that atti-nipteil by other investigators, a method for estimat- 

 ing the requirements of the soil, which should give more reliable indi 

 cations of the sn|)i)ly of a\ ailable itlant food in the soil than is given 

 by the i)resent methods ors«)il analysis. 



Seven plats were selected, each of which contained 8 subdivisions. 

 Since 1874 the 8 snbjdats of each series had received the following fer- 

 tilizers each year: (1) Potash, (2) jiitrogen, (^) phosphoric acid, (4) 

 potash, nitrogen, and i)hosi)horic acid, (5) unfertilized, (0) potash and 

 nitrogen, (7) potash and i)lios]dioiic acid, and (-S^ phosphoric acid and 

 nitrogen. Fonr of the^c 7 ]>lats had receiveil the same crops each year 

 (peas, oats, rye, and potatoes, respectively); on the others rotation had 

 been practiced. The yields for several years had left no doubt that the 

 soil was delicient in potash and nitrogen, but contained sufficient phos- 

 ])liori(' acid. It" it is]iossible to determine the reqnirenn'iits of a soil by 

 means of plant analysis the examination of the crops grown on the plats 

 mentioned shonld answer this (pu'stion. 'Die analysis of the rye grown 

 on plat ."» in ISitO, which on account of being hulged had to be mown 

 while still green, showed that the percentage of phosphoiic acid was 

 the sann- in the crop from all the subplats, but that the percentages of 

 ])Otash and nitrogen varied widely. To furtlier follow this matter, 

 snninier wheat was sown on ])Iat 5 and on 2 adjoining plats. The 

 crop was harvested when in bloom, since, according to earlier investi- 

 gations on the course of assimilation of plant food from the soil, assinn- 

 lation is practically at an end at this stage. The analyses show, 

 as in the i)i-evious year, that the percentage of phosjdioric a<it] 



