198 IRRIGATION FARMING. 



especially in heavy soils. The tendency of the soil after 

 each irrigation is to sun-bake, and thus prevent a free 

 circulation of air through it. It is for this reason that 

 cultivation almost immediately after the water is drawn 

 off is requisite to successful orchard growth under irri- 

 gation. Often a thorough stirring of the soil is as good, 

 if not better, than an irrigation. Seasons also differ. 

 During some the rainfall is sufficient to carry trees well 

 into the summer without irrigation. If summer and 

 winter mulching is practiced, less water is required, be- 

 cause a good mulch arrests evaporation and preserves an 

 even temperature around the tree. In fact, we have 

 known orchards with a good mulch and thorough culti- 

 vation to pass through the season with but one watering. 

 Occasionally the soil is sufficiently moist to permit of 

 this without a mulch if the cultivation is good. But 

 these instances are, of course, the exception, and will 

 not do for a guide in any general sense. 



The writer cultivates his orchard mostly with a 

 double shovel five times a year, allowing no grass or 

 weeds to grow, as they greatly aid in harboring mice. 

 We do not grow corn or small grain in the orchard, as 

 these crops take the substance of the soil needed for the 

 trees, which are certainly of sufficient importance to have 

 the benefit of the entire ground. Melons can be grown 

 without detriment. Put no crop in the orchard after 

 the third year. Mulching to delay blooming is not a 

 success. The California plan is to plow the orchard 

 twice annually, the first time as early as February, and 

 again in April. Plow away from the trees the first 

 time and towards the trees the second time. They 

 keep up the cultivation almost constantly throughout 

 the summer, whether irrigation is given or not. Some 

 men use a chisel tooth cultivator, while others use a 

 gang plow. The duck-foot cultivator is a very common 

 implement and gives good satisfaction, while some men 



