138 



CALIFORNIA FRUITS: HOW TO GROW THEM 



tion 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 or- 

 ganic matter 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 to take up the plow dur- 

 ing late winter or early spring, to turn under a winter growth of a 

 legume sown for the purpose or 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 ra- 

 tional and satisfactory practice for most of our deciduous orchards, 

 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 pulver- 

 ization 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 foundation upon which to rest 

 the year's 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 surface 

 smooth and polished. It may reflect the sunheat even to tree- 

 burning, and is apt to form an evaporating surface, which is almost 

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

 light, fine-toothed harrow, and an attachment of this kind is provided 

 with various clod crushers and cultivators. The result is a surface 

 of loose earth, flat and fine, which approaches very closely an ideal 

 condition. 



There is less difference than formerly in the use of the harrow 

 or cultivator during the summer. Still some are content to use the 

 cultivator only as a weed-killer, and after the weeds cease to grow 

 and the spring showers are over, the cultivator is laid aside and the 



