EFFECT OF LIME UPON AVAILABILITY OF SOIL CONSTITUENTS. 61 



NOTE ON the EFFECT OF LIME UPON the AVAIL 



ABILITY OF the SOIL CONSTITUENTS. 



By F. B. Guthrie, f.i.c., f.c.s., and L. Cohen. 



[Read before the Royal Society of N.8. Wales, August 7, 1907.'] 



The experiment here described was undertaken with the 

 object of determining to what extent the availability of 

 the soil constituents is affected by the addition of lime. 

 Three kinds of soil were used in the experiment, a light 

 sandy soil, a garden loam fairly rich in humus, and a very 

 stiff clay soil. The soils were well mixed, passed through 

 a sieve with 1 millimetre mesh, and about 10 lbs. of each 

 placed in an ordinary 11 inch terra-cotta unglazed pot, 

 closed at the bottom with a cork. Duplicate portions 

 sifted as above were thoroughly mixed with 1°/° freshly 

 slacked lime and potted in duplicate. 



The pots were placed for a month in a position exposed to 

 sun, rain and wind, and kept moist the whole of the time. 

 On three occasions they were saturated with heavy showers 

 but did not overflow. The clay soil which had been treated 

 with lime had undergone considerable physical changes, 

 having become quite friable and easily broken up by the 

 fingers at the end of a fortnight. 



At the time of filling the pots, samples of the original 

 soils in an air-dried condition were taken for the deter- 

 mination of the plant-food soluble in hydrochloric acid, 

 citric acid, and water. The analyses are as follow : — 



Analyses of Original Soil. 



Clay. Loam. Sand, 



(CaO... '742 ... .827 ... '109 

 Soluble in HC1 S.G. 1*1 1 K.O '241 ... '103 ... '031 



(P 2 O s *184 ... -348 ... -074 



