ILLUSTRATIONS. 



PLATES. 



Page.' 



PLATE I. Interior of a coniferous windbreak in northeastern Iowa. Frontispiece 

 II. Fig. 1. Cottonwood is preeminently the tree of sandy bottom- 

 lands. Fig. 2. Belts of silver maple and other species add 



to the beauty and value of farms 8 



III. Fig. 1. Narrow belts of eucalypts are planted about the orange 

 orchards of California. Fig. 2. On irrigated lands in Colo- 

 rado the Lombardy poplar grows thriftily ' * 8 



IV. Fig. 1. The Monterey cypress makes an excellent windbreak.] 

 Fig. 2. Dense groves of eucalypts protect fields and orchards 



from the Santa Ana ' 8 



V. Fig. 1. White cedar and European larch are typical of the 

 Lake States and the East. Fig. 2. Monterey pine is thrifty 



and forms an efficient windbreak 8 



VI. Fig. 1. A north-south row has the advantage of getting light 

 from the sides. Fig. 2. An east- west row receives light 



only from above 16 



VII. Fig. 1. Corn to the north of a cottonwood grove is badly dam- 

 aged by shade. Fig. 2. On the east of cottonwood the shad- 

 ing effect is not so marked 16 



VIII. Fig. 1. Alfalfa grows almost to the base of honey-locust trees. 

 Fig. 2. The yield even of alfalfa is comparatively small 



under dense shade 16 



IX. Fig. 1. The branches of ash are small and the tree does little 

 damage by shading. Fig. 2. Kafir corn will produce forage 



where corn would produce no ears 32 



X. Fig. 1. Effect of cultivation on osage orange. Fig. 2. Large 



trees not only take moisture but injure by shading 32 



XI. Fig. 1. Luxuriant growth of protected orchard trees. Fig. 



2. Wheat near the trees has been benefited by drifted snow. . 40 

 XII. Fig. 1. Sand dunes near the Columbia River. Fig. 2. Sand 



encroaching on a railroad track 40 



XIII. Fig. 1. Lombardy poplar protecting an orchard. Fig. 2. 

 Dense hedges of mulberry protect orchards from wind and 



from sand 40 



XIV. Fig. 1. The hedge of honey locust is very loose and open. 

 Fig. 2. Comparative densities of honey locust and osage 



orange 18 



XV. Fig. 1. Effect of windbreak protection on quality of corn. 



Fig. 2. Effect of favorable conditions on growth of corn 04 



XVI. Fig. 1. A thrifty cottonwood grove with possibilities for high 

 future value. Fig. 2. Conditions within the grove favor the 



production of straight sound logs cSO 



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