﻿50 BULLETIN 24, U. S. DEPARTMENT OF AGRICULTURE. 



a decided profit. Commercial planting in this region, however, 

 should be restricted to bottom lands, or, in the case of windbreaks, 

 to good farm land. (See PL V, fig. 1.) 



The possibility of combining timber growing with windbreak 

 planting opens up an important field for cottonwood in the Middle 

 West on farm lands too valuable to permit of timber production for 

 its own sake. One of the chief requisites in a windbreak tree is rapid 

 height growth. Cottonwood meets the requirement better than any 

 other species. It is adapted to any good, moist situation, such as 

 liver bottoms, or even typical farm land of the rolling uplands of 

 the eastern portion of the region, where rainfall is comparatively 

 heavy. On dry situations, where long droughts are common, a less 

 exacting tree is better. 



There is, however, a serious objection to cottonwood for wind- 

 breaks, due to the sapping effect of its roots upon adjoining crops. 

 It is generally considered more injurious in this respect than any 

 other tree used for windbreaks in this region, and many farmers are 

 cutting down groves or belts of cottonwood with no intention of 

 replanting it. As a matter of fact, however, actual measurements 

 made by the Forest Service show conclusively that in comparison to 

 its height cottonwood is the least injurious of any species commonly 



used. 1 



The sapping effect of cottonwood, as of any other tree used for 

 windbreaks in the Middle West, is almost always more than offset 

 by the increased crop yield on the fields protected. Windbreaks in 

 this region will usually more than repay the rental for the actual area 

 of valuable farm land which they occupy without even taking into 

 account the direct financial returns from marketing the wood 

 product. 



Since the tree's foliage is rather open, cottonwood windbreaks 

 should be underplanted with a shade-enduring species either as soon as 

 the stand begins to open up or else at the outset. For this purpose any 

 one of the following trees will do: white or green ash, red oak, box- 

 elder, and silver maple. Another method of overcoming this diffi- 

 culty would be to plant only two or three rows of cottonwood the first 

 year, and to plant additional rows on the side most exposed to the 

 sunlight as soon as the original trees show a tendency to become open. 

 Two hundred and forty feet has been recommended as the most suit- 

 able width for a windbreak belt of cottonwood in this region. 



PREPARATION OF SITE. 



Planting without a thorough preparation of the site is inadvisable. 

 On freshly cut-over land the preparation should be practically the 

 same as for natural reproduction. Full sunlight is equally indis- 



1 Forest Service Bulletin 8G, " Windbreaks." 



