152 



CALIFORNIA FRUITS: HOW TO GROW THEM 



grow. This practice is, however, becoming less prevalent, and for 

 certain soils the question is practically settled in the minds of nearly 

 all orchardists, while for other soils there is still doubt. For 

 the heavier soils, which continuous shallow cultivation is apt to 

 render too compact, it is necessary to have recourse to the plow to 

 open the land for proper aeration and penetration of moisture 

 which otherwise would be largely lost by surface run-off. The 

 lighter soils do not require this and they seem to do well with 

 continuous use of the cultivator. It is beginning to be clearly 

 seen, however, that this treatment tends toward the decrease of 

 the humus and the consequent impoverishment of the soil. Its 

 water-holding capacity is also lessened. These facts have induced 

 some growers to change their practice and take up the plow during 

 late winter or early spring to cover in the growth of green stuff 

 which they allow to grow instead of frequently destroying it with 

 the winter use of the cultivator. Either the fall and spring plowing, 

 or both, followed by the summer use of the cultivator, is the most 

 rational and satisfactory practice for most of our deciduous orch- 

 ards, though there are local conditions and circumstances under 

 which different procedure is preferable. 



SUMMER CULTIVATION 



Whatever the winter policy may be, the essential point in sum- 

 mer cultivation is to preserve the surface layer of pulverized 

 earth. It will not do to have a few inches of clods, from the size 

 of a pea to that of a goose egg, resting on. a hard surface. The 

 finer the pulverization the shallower can be the surface layer, and 

 vice -versa, and this is probably one reason why in practice the 

 work of the plow is, in so many situations, found the best founda- 

 tion upon which to rest the years' cultivation. 



In order to secure this finely-pulverized layer, it is sometimes 

 necessary to use what is called a "rubber," where there are many 

 clods which are merely displaced by the harrow or cultivator. 

 There are different styles, and they are generally home-made. 

 The most common form is made of two-inch plank in lengths of 

 three or four feet, bolted or spiked to pieces of four-by-four-inch 

 scantling running crosswise, the edges of the planks lapped like 

 the clapboards which are used for weather boarding. As these 

 edges are drawn over the surface, the clods are rubbed into tilth 

 if they are not too hard and dry. 



But this rubbing may be very undesirable if it leaves the sur- 

 face smooth and polished. It may reflect the sunheat even to 

 tree-burning, and is apt to form an evaporating surface, which is 

 most to be avoided. The best finish for the land is that produced 

 by a light, fine-tooth harrow, and an attachment of this kind is 

 provided with various clod crushers and cultivators. The result 



