CHAPTER XIII 



CULTIVATION 



Statistics from the different parts of the country and surveys of 

 the orchards throughout all the apple-growing regions show clearly 

 that it is the clean-culture method of apple growing that predomi- 

 nates. Perhaps the reasons for this may be understood better after 

 a study of the objects of cultivation. 



Objects of cultivation. Cultivation conserves moisture. Un- 

 doubtedly the most important single function of cultivation is that 

 of conserving the moisture of the soil. Let rain fall and the sun 

 shine, and the soil forms a crust which allows the evaporation of 

 moisture, thereby robbing the soil storehouse of its great treasure. 

 It can be easily understood how this moisture is lost when the soil 

 is likened to a collection of very small tubes, all ending at the 

 surface of the soil, each tube containing water that is continually 

 being brought up to the surface to replace that which is taken away 

 by evaporation, either by the sun's rays or by the movement of the 

 air. As soon as some tool breaks up the ends of these tubes, the 

 movement of water almost ceases because of the soil blanket, which 

 has been effectively placed between the evaporating medium and 

 the tube ends. 



Moisture is lost not only from the crust formed on the soil after 

 a rain but also from the cracks or fissures which are often found 

 in the soil and which increase the exposed surface. An orchard 

 in such a condition is in need of serious attention. 



Since all the mineral elements are taken from the soil in a 

 liquid condition, lack of sufficient moisture in the soil prevents 

 the plants from securing food through their roots. Therefore, no 

 matter how rich the soil is in the necessary plant-food elements, 

 — potash, phosphorus, iron, etc., and even the evasive nitrogen, — 

 they are of no value to the plant unless sufficient moisture is at 

 the same time available in the soil. 



