132 CALIFORNIA FRUITS I HOW TO GROW THEM 



How Exhaustion by Inter-Culture May Be Avoided. But all 



inter-cultures are a loan made by the trees to the orchardist. The term 

 may be very long and the rate of interest very small in some cases, but 

 sooner or later the trees will need restitution to the soil of the plant 

 food removed by inter-cropping. This may be accomplished by the 

 use of fertilizers. Still the rule that the trees or vines should have all 

 the ground is generally true. It is also true that on merely ordinary 

 soils, trusting to rainfall, or on shallow soils, trusting in part in irriga- 

 tion, the trees or vines should have the full strength of the land and all 

 the help which can be given them in the shape of thorough cultivation. 



METHODS OF TILLAGE 



In general terms the main objects of tillage of orchard and vine- 

 yard are two : Winter cultivation for moisture reception, and summer 

 cultivation for moisture retention. 



Wherever early winter plowing can be done without too great 

 danger of soil washing, it affords the best available means of admitting 

 water to the great reservoir in the lower levels a deep soil. Too fre- 

 quently large volumes of rain water, enriched by air-washing as it falls 

 and by fine soil-particles as it flows, are allowed to run off into the 

 country drainage, with the double loss of fertility and moisture to 

 the fruit grower. Deep penetration of winter rains should be, in all 

 safe ways, promoted. Cultivation for retention has already been 

 strongly urged and is quite generally recognized. 



To serve these main purposes there are two main divisions of prac- 

 tice in this State, each of which has variations of greater or less 

 importance. 



First : Winter plowing followed by frequent use of cultivator and 

 pulverizer in summer. 



Second : Use of cultivator at intervals both winter and summer, 

 following, if needed, with pulverizer in the summer. 



The main features of each division of practice, and some of the 

 claims by which each method is supported by its advocates, will be 

 noted. 



Plowing Orchard and Vineyard. There is considerable varia- 

 tion in the practice of plowing orchard and vineyard, in the kinds of 

 plows employed, and the times chosen for the work. Some plow but 

 once, toward spring, whenever the ground is in suitable condition; 

 and, if there is much growth of weeds and clovers, a looped chain is 

 run from the plow to the end of the evener to aid in drawing under 

 the tall growth. Sometimes, however, the growth gets so rank before 

 the soil is in condition to plow that the weeds are mown before 

 plowing. Where but one plowing is done, the soil is usually thrown 

 away from the trees and afterwards is leveled back by harrowing or 

 cultivating. If this practice is adopted, care should be taken that the 

 soil is properly returned about the tree roots, for injury is sometimes 

 done by bringing the roots too near the surface, which is soon after- 

 wards intensely heated by the sunshine. 



