BULLETIN 398, U, ^. DEPARTMENT OF AGEICULTURE. 



DESCRIPTION OF THE JUDITH BASIN. 



The following rather detailed description of the Judith Basin and 

 the conditions obtaining there allows comparison with other parts 

 of the State of Montana where it is believed that the substation 

 results are apphcable. 



TOPOGRAPHY. 



The Judith Basm is an area of nearly 2,000,000 acres of tillable 

 bench land lying in the western half of Fergus County, Mont. The 

 basin, so called because it is nearly surrounded by mountains, is 

 about 75 miles from east to west and 50 miles from north to south. 

 The Little Belt Mountains form the southern and western boundaries. 

 The Highwood Mountains and the Bad Lands, or breaks, of the 

 Missouri River lie to the north. The North and South Moccasin, the 

 Judith, and the Snowy Mountains form the eastern boundary. 

 The basin is drained by the Judith River and its tributaries. Part 

 of the land along the river and creek bottoms can be irrigated, but by 

 far the larger part of the district is classed as dry land. 



Until a few years ago the Judith Basin was a range country. The 

 only land farmed was along the river and creek bottoms, while the 

 bench lands were used to pasture great herds of oattle and sheep. 

 Within the last 10 years practically all the tillable land in the Judith 

 Basin has been brought under cultivation. Winter wheat is raised 

 almost exclusively, although a few of the farmers are gradually 

 working into a more diversified system of farming. 



SOILS. 



The soils of the Judith Basin are rather variable. The surface soil 

 is a dark, heavy clay loam of limestone origin, which varies in depth 

 from a few inches to 3 feet. The soil when wet becomes very sticky, 

 and because of its adhesive character can be plowed only with a disk 

 plow. Analysis of the soil shows that apparently it is quite rich in 

 available plant food. The subsoil to a depth of 30 feet is composed 

 of limestone gravel closely cemented together and is of such character 

 as will not allow the storage of water or the development of roots. 



The composition of the soil at the substation, as determined by 

 mechanical analysis, is shown in Table I. The stickiness of the soil 

 is due largely to its high percentage of silt and clay, 40.7 and 24.3 per 

 cent, respectively, in the surface foot. 



Table I. — Composition of the soil at the Judith Basin substation, Moccasin, Mont., as 

 deterinined by mechanical analysis. 



Constituents. 



Fine gravel... 

 Coarse sand . . 

 Medium sand 

 Fine sand 



First 

 foot. 



Per cent. 

 0.9 

 2.7 

 4.4 

 13.3 



Second 

 foot. 



Per cent. 

 1.1 

 2.3 

 3.2 

 10.4 



Constituents. 



Very fine sand 



Silt 



Clay 



First 

 foot. 



Per cent. 

 13.4 

 40.7 

 24.3 



Second 

 foot. 



Per cent. 



11.6 



'33.3 



38.1 



