132 THE CULTURE OF FARM CROPS. 



especially subject to it, and are consequently difficult to 

 work and at times the crops suffer on such soils. Then 

 thorough drainage, or the admixture of a large quantity of 

 sand or vegetable matter or lime, or all of them are needed 

 to secure the largest possible crops. In the end these meth- 

 ods will bring the stiffest clay soil to a condition in which 

 it may be worked to advantage, but the cost of all this is to 

 be taken into account when a farm is examined with a view 

 to its purchase, or when methods are required to bring it to 

 a condition of suitable pulverization. In this case the far- 

 mer will do well to study the character of the implements 

 he employs very carefully, and choose those which are the 

 most effective for this purpose, so that the land may be most 

 perfectly and economically worked. 



Some soils are extremely adhesive and clog the imple- 

 ments even when made of the best, the hardest, and the 

 smoothest metal. All soils are more resistant to the plow 

 when wet, than when dry, and also to an iron than to a 

 chilled or steel plow. While the resistance of a sandy soil 

 when wet, is equal to 4 Ibs. to the square foot of the surface 

 which passes through it, a fertile vegetable soil or a rich 

 loam, exerts a resisting force of about 6 Ibs. and clay 

 soils from 8 to 25 Ibs. to the square foot. These differences 

 will certainly form considerable items in the calculation of 

 a farmer who is estimating the cost of working, or the ef- 

 fectiveness of it, and the consequent value that may be put 

 on the land. 



The capacity for absorbing and holding water is of para- 

 mount importance to the soil, for the ability to produce crops 

 depends greatly upon this quality. Soils vary greatly in 

 this respect ; as will be shown in the following instances. 

 When a sample of soil is dried thoroughly in a moderately 

 cool oven, or on a plate placed over boiling water, and is 

 then spread out on paper in the open air, it will take up 

 watery vapor from the atmosphere, and will thus increase 

 in weight. The capacity of the soil in this respect may be 

 easily tested by weighing accurately 100 ounces of soil dried 

 for 24 hours in the manner above described. Kich garden 



