10 ' BULLETIN 50, U. S. DEPARTMENT OF AGRICULTURE. 



soil, but there are many gravel beds that have only a thin covering 

 of fertile soil. Much of the soil, particularly of the benches and 

 low hills, is composed largely of material deposited by the melting 

 of the ice sheet that formerly covered the land. 



Drainage is an important and widespread need in Alaskan agri- 

 culture, not merely in the southeastern section where the rainfall 

 is so abundant, but in the interior where the precipitation is so light 

 that irrigation is thought by some to be a possible essential. 

 TTherever the soil is at all peaty, from the accumulation of partly 

 decayed vegetable matter, drainage will greatly improve the con- 

 dition. Shallow lakes and partially dried lake beds abound, and 

 the draining of these will make available for tillage much good 

 land and will be otherwise beneficial. It is noticed that wherever 

 the tundra moss is disturbed in such a way that drainage has re- 

 sulted incidentally, as has been done at St. Michael in connection 

 with building operations, grasses come in and make a luxuriant 

 growth. 



Notwithstanding the need of drainage, even in the interior, as 

 has been stated, some of the settlers are of the opinion that irriga- 

 tion will be necessary in certain localities, and a few have installed 

 irrigation systems. It is not probable, however, that irrigation will 

 be a general or pressing need. The ground is usually frozen to a 

 great depth during the long and severe winters and, of course, thaws 

 quite slowly after the frost line has fallen a foot or so. So long 

 as there is frost in the ground drainage will be retarded, and as the 

 frost slowly melts it will supply moisture by capillarity to the surface 

 soil. The shortness of the growing season and the tendency of 

 vegetation to rapid growth and early maturity under the influence 

 of the almost continuous sunlight will lessen the need of irrigation. 



POSSIBLE AGRICULTURAL AREAS. 



So far as topography, soil, and climate determine the matter, 

 Alaska has probably 100,000 square miles of area on which there 

 are possibilities for farming and grazing. The larger portion of 

 the farming land is in the interior, in the Yukon drainage. Not- 

 withstanding the mildness of the climate and the accessibility of 

 the south coast, the precipitous topography to the water's edge makes 

 tillable land very limited, particularly in the southeastern section, 

 where the excessive precipitation and much cloudy weather are also 

 agricultural handicaps. Of tillable land contiguous to the south 

 coast from southeastern to southwestern Alaska, probably not more 

 limn 1,000 square miles are available. In the Copper River drain- 

 age, 100 miles back from the coast, there are possibly 2,000 square 



