Soils in the first four classes are capable under good management of pro- 

 ducing adapted plants, such as forest trees or range plants, and the common 

 cultivated field crops and pasture plants. Soils in Classes V, VI, and VII 

 are suited to the use of adapted native plants. Some soils in Classes V 

 and VI are also capable of producing specialized crops, such as certain 

 fruits and ornamentals, and even field and vegetable crops under highly in- 

 tensive management involving elaborate practices for soil and water conser- 

 vation. Soils in Class VIII do not return onsite benefits for inputs of 

 management for crops, grasses, or trees. 



The grouping of soils into capability units, subclasses, and classes is 

 done primarily on the basis of their capability to produce common culti- 

 vated crops and pasture plants without deterioration over a long period. 

 To express suitability of the soils for range and woodland use the soil- 

 mapping units are grouped into range sites and woodland sites. 



CAPABILITY CLASSES 



Land suited for cultivation and other uses 



Class I . — Soils in Class I have few limitations that restrict their use. 



Soils in this class are suited to a wide range of plants and may be used 

 safely for cultivated crops, pasture, range, woodland, and wildlife. The 

 soils are nearly level, 1/ and erosion hazard (wind or water) is low. 

 They are deepj generally well drained, and easily worked. They hold water 

 well and are either fairly well supplied with plant nutrients or highly 

 responsive to inputs of fertilizer. 



The soils in Class I ajre not subject to damaging overflow. They are pro- 

 ductive and suited for intensive cropping. The local climate must be 

 favorable for growing many of the common field crops. 



In irrigated areas, soils may be placed in Class I if the limitation of 

 the arid climate has been removed by relatively permanent irrigation works. 

 Such irrigated soils (or soils potentially useful under irrigation) are 

 nearly level, have deep rooting zones, have favorable permeability and water 

 holding capacity, and are easily maintained in food tilth. Some of the 

 soils may require initial conditioning including leveling to the desired 

 grade, the leaching of a light accumulation of soluble salts, or the low- 

 ering of the seasonal water table. Where limitations due to salts, water 

 table, overflow, or erosion are likely to recur, the soils are regarded 

 as subject to permanent natural limitations and are not included in Class I. 



1/ Some rapidly permeable soils in Class I may have gently slopes. 



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