11 March. 1918.] Apple Culture in Victoria. 



135 



cropping, and the orchardist is obliged to use artificial fertilizers, 

 superphosphate especially, the lime gradually disapi^ears. 



An occasional dressing of lime produces a mechanical or physical 

 change in the texture of heavy clay soils, by which they are rendered 

 more friable and less tenacious, while the cohesive properties of light 

 sandy soils are enhanced by similar treatment. Lime may be used in 

 any of four forms — quicklime, slaked lime, ground limestone, and 

 gypsum. Quicklime is the most alkaline, and, when incorporated in 

 sour soil, soon destroys its acidity by uniting with the acids, and 

 changing them into harmless substances, which are neither alkaline nor 

 acid. 



The map on page 134 shows the localities in which limestone deposits 

 are situated in Victoria. 



Most practical fruitgrowers are able to determine by the general 

 appearance of the soil when it has developed acidity. The less experi- 



Plate 156. — Steer's Limestone Quarry, Warrnambool, showing accumulation of 

 limestone sand in the foreground. 



enced orchardist, hoAvever, may ascertain the condition of his soil in this 

 regard by using blue litmus paper. To make the test cut a slit with a 

 knife in the moist earth, place a strip of the paper in the slit and close 

 the earth in against it. If, after a few minutes, when the paper becomes 

 moistened, it turns pink or red the soil is acid, and the redder tlie colour 

 of the paper the more acid the soil. 



Sourness is often caused by stagnant water in orchards with retentive 

 clay subsoils, and in cases of this kind subdrainage should receive first 

 consideration, then an application of lime hastens the sweetening of such 

 soils. 



