302 EXPERIMENT STATION RECORD 



" Soil tests with fertilizers have sliowu that the soil of Kingston Plain can not be 

 profitably cultivated without luiiuediate resort to phosphatic fertilizers, though the 

 contrary would be inferred from the percentage of i)hosphoric acid and lime as shown 

 by the regular method of chemical analysis, provided the results are interpreted 

 upon Hilgard's basis for virgin soils. It appears, therefore, that soil tests with fer- 

 tilizers furnish, at ])resent, more reliable data for arriving at the actual needs of our 

 soils than does the ordinary method of chemical soil analysis. . . . 



"One important point has been l)rought out with great emphasis during our 

 examinations of the soil of Kingston Plain, viz, the importance of recognizing the 

 presence or absence of any considerable degree of soil acidity. At least among 

 American writers the opinion ai)parently prevails that an injurious degree of soil 

 acidity is practically never met with excei>t in bogs or wet, marshy lands, some- 

 times referred to as 'sour, wet lands.' . . . 



"The fact that a degree of soil acidity which is highly detrimental to certain 

 agricultural plants is liable to exLst even in the case of naturally well-drained 

 and upland soils has not, we believe, been heretofore sufficiently recognized, and 

 chemical tests for the same have been too frequently omitted in the course of soil 

 examinations. . . . 



"Some reports Avhich have come to us of inability to grow successfully ruta- 

 bagas, onions, and more especially beets, spinach, lettuce, etc., even when amply 

 fertilized, may find their explanation along the hue of too great soil acidity. . . . 



"In case of acid soils (i. c, soils which when moistened impart to blue litmus 

 paper a red color, which x»ersists aft(!r drying) an application of caustic or carbon- 

 ate of lime, not gypsum or ])la8ter, has always ])rov('d to be an efficient remedy." 



The use of lime in form of good marl, wood ashes, leached and 

 unleached, and air-slacked lime is believed to be more economical in 

 actual ])ractice than that of other alkaline carbonates, or of barnyard 

 manure in liberal doses, although these are believed to be effective 

 means of correcting acidity. 



Alkaline soils of Canada, F. T. Shutt {Canada Exptl. Farms Rpt. 

 1893, pp. 135-110, dgms. 3). — Analyses of 4 samples of alkaline soil 

 from Manitoba contirm the conclusions from ])revious examinations 

 (E. S. R., 4, p 433; G, \). 124) " that sul[)hate of magnesium, and not sul- 

 phate or carbonate of soduim (the usual form of alkali), was, in all 

 probabdity the cause of the barrenness of the soil.'" 



In order to determine an effective means of correcting this alkali a 

 series of pot experiments was commenced in 1892 and continued in 

 1893. The results, which are also shown in diagrams, were as follows: 



"In soils to which 5 per cent of magnesium sulphate (Epsom salts) had been 

 added the germination of the seeds was always greatly retarded. Many of the 

 seeds sown never produced plants that ai)peared above the surfiice of the ground, 

 while those which came \\\\ lacked robustness, made but little growth, and then 

 died. All the experiments i)roved that magnesium sulphate to the extent of 5 per 

 cent in the soil is most disastrous to plant life. 



"In another series suthcient carbonate of lime, iii the form of powdered chalk, 

 was mixed witli the soil to theoretically convert, after the la{)se of time, the 5 per 

 cent of magnesium sul])hate into an inert and insoluble compound. In these pots 

 gerrainatiou was also delayed, though not so long as in the former series, and a 

 greater percentage of plants gn-w, though their development was not equal in 

 vigor or luxuriance to those in tlie potting soil. To a certain extent carbonate of 

 lime had counteracted the deleterious etfects of the magnesium sulphate. 



" Further experiments were then commenced, in which lime was substituted for 



