8 



and filling the depressions where otherwise water would collect. Rolling 

 land or land having a steep slope usually requires little grading. 



The implements needed for grading are usually some form of scraper 

 and a smoother or leveler. For removing large knolls or for carrying con- 

 siderable earth the Fresno scraper, which is a wide steel scraper, is ex- 

 tensively used. For loose sandy soil and where the haul is short, the Buck 

 scraper is very effective. It is used extensively in the Yakima Valley and 

 in nearly all irrigated districts. It consists of a board 10 to 14 feet wide, 

 shod along one edge with a steel plate, which can be adjusted to any angle 

 by means of a lever arrangement connected to it and to a foot board or tail 

 board (Fig. 1). To finish the surface smooth a leveler sometimes called 

 float or drag is used after the scraper (Fig. 2). 



Fig. 1. Buck scraper for leveling land. 



(Farmers' Bulletin 373, U. S. Dept. Agr.) 



Fig. 2. Leveler or float. 



(Farmers' Bulletin 392, U. S. Dept. Agr.) 



2. Growing Crops to Improve Condition of Soil. 



Most soils of the arid type are lacking in organic matter or humus and 

 can be much improved by preliminary cropping to plants which will add 

 humus and bring the soil into good condition. The crops used are clover, 

 alfalfa, peas or cereals. Prof. Fisher, horticulturist for the Montana Agri- 

 cultural College, states that a method which is practiced with success is to 

 plow the land deep in the fall and grade it. In the spring following oats 

 and red clover are planted. The oats are harvested the following fall and 

 the next year one crop of clover hay can be cut and the second crop plowed 

 under as a green manure. Prof. Judson, horticulturist for the University 

 of Idaho, recommends clover the first season, plowed under in the fall, and 

 potatoes or other hoed crop planted the following spring. 



