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BULLETIN 518, U. S. DEPARTMENT OF AGRICULTURE. 



the distant hills. One can invariably pick out the orchards under 

 the two kinds of soil management by the appearance of the foliage, 

 that of the intensively clean cultivated orchards often having a light 

 yellowish appearance. Lack of irrigation of course has much to do 

 with this difference, but even irrigation without the addition of 

 humus will not long give color and health to a bearing orchard. The 

 older the orchard, the more noticeable is the difference in the physical 

 condition of the trees under the two systems of management. 



The average soil of the valley is of such a type that it becomes non- 

 productive after excessive cultivation. This is one reason why the 

 use of a mulch crop shows results. The costs also show an advantage 



Fig. 10. — A clean-cultivated orchard which has never been irrigated. The trees are 

 Esopus and Newtown and are in need of humus or nitrogen. 



in favor of the mulch crop. The maintenance labor is $43.63 per 

 acre, or $0.2001 per box, for the 30 clean-culture orchards. The net 

 labor cost in the case of the 24 mulch-crop orchards is $35.41 per acre, 

 or $0.1554 per box. Thus there is a difference in maintenance labor 

 of $8.22 per acre, or $0.0447 per box in favor of the mulch-crop sys- 

 tem. Also yields are higher under the mulch-crop system, and the 

 orchard is more healthy and has a better appearance generally. 

 These advantages will undoubtedly become more and more apparent 

 as the system becomes better established in these orchards and has 

 more time to show results. In considering the farms studied it 

 would seem best not to leave the crop down too long, but to turn it 



