DIFFERENT KINDS OF CULTIVATION 139 



land left unstirred until the following winter. This, of course, refers 

 to unirrigated ground, for wherever irrigation is practised a culti- 

 vator must follow, except on hillsides where the surface is left undis- 

 turbed after the irrigation furrows are made for the season. It is 

 a fact, however, that even if no rain falls, the soil becomes compacted 

 to a certain degree, and the best way to imprison the greatest pos- 

 sible amount of moisture below is to run the cultivator at intervals 

 all through the dry season. It should run shallow and only stir the 

 surface layer. The experience of the most successful growers is that 

 frequent stirring without, however, bringing new soil to the air, is 

 the best-paying practice. 



. WHAT IS THOROUGH CULTIVATION 



As clean, thorough cultivation has been approved, it may be 

 desirable to attempt to define the term. It can, however, only be 

 approximately done, because of the great difference in individual 

 views and practices. Some indication of the operations which are 

 contemplated may be had in the following specifications upon which 

 contracts have been let for care of orchard : First, plowing away 

 from the trees, followed by harrowing ; second, plowing toward the 

 trees, followed by harrowing ; ten summer workings with cultivator ; 

 three working with shallow cultivator or weed-cutter; five hand 

 hoeings around the trees. The contract intends the most complete 

 and perfect working of the soil and specifies the above merely that 

 there may be no difference of opinion between owner and contractor. 



With the best team and implement work which can be done there 

 always remain the need of quick hand work in hoeing around the 

 trees. As an offset to the cost is the additional moisture-conserva- 

 tion, for hard ground around a tree sucks out and evaporates much 

 moisture and draws it sidewise from far beyond its own area. Hard 

 soil in contact with the bole of a tree is apt to pinch the bark, pre- 

 vent expansion and perhaps cause gumming. It is also a safe refuge 

 for many kinds of pests which a good stirring may destroy. 



CULTIVATION FOR WEED KILLING 



Cultivation for weed killing is a minor consideration in Cali- 

 fornia, because cultivation for moisture conservation effectually dis- 

 poses of most of them, and weeds do not start readily in the earth- 

 mulch during the dry season. There are, however, a few most per- 

 sistent pests which require heroic measures. Johnson grass and 

 morning-glory are the most prominent of these.* The only suc- 

 cessful treatment consists in cutting constantly with a weed-cutter 

 (a sharp horizontal knife), operated so as to pass under the whole 

 surface and run so often that the plant is never allowed to show a 

 shoot on the surface. It is of no use merely to cultivate or "weed- 

 cut" as for other weeds. This spreads the pest more and more ; but 



'Special publications on reduction of morning-glory and other running weeds and 

 grasses, can be had by application to the College of Agriculture, Berkeley. 



