54 The Bulletin. 



it, therefore, as a law. that the transporting power varies as the sixth power 

 of the velocity. If the velocity, therefore, be increased ten times the trans- 

 porting power is increased one million times." But "the transporting power of 

 water must not be confounded with erosive power. The resistance in one case 

 is weight, in the other cohesion; the latter varies as the square, the former as 

 the sixth power of the velocity." However, cohesion is greatly reduced in the 

 presence of water and weight lessened by its buoyancy. If, as has been 

 shown, the transporting power of water is made sixty-four times greater by 

 doubling the velocity, the converse of the law is also true, and a correspond- 

 ing reduction in the velocity of a current will correspondingly reduce its force 

 or working power as applied to weight, erosion and transportation. A cur- 

 rent capable of moving an obstacle weighing G4 pounds could move an obstacle 

 weighing only 1 pound should its velocity be checked one-half. It may, then, 

 be readily understood that all rain-water induced to enter the soil as it falls 

 is robbed of its gullying power, and if that which must flow off is checked to 

 one-half its velocity, its gullying power is reduced sixty-four times. 



The excessive gullying taking place in that area lying between the Ohio 

 River and the Gulf of Mexico and the Mississippi River and the Atlantic 

 Ocean is due in part to natural conditions enumerated as follows : 



1. Heavy and irregular rainfall. 



2. Irregular, broken and steep topography. 



3. Soils which erode and transport easily on account of the character of the 

 soil particles. 



4. Soil characters which cause the surface to expand and intersoil spaces 

 to close when wet, thus sealing up the surface and checking the flow of rain- 

 water into the soil. 



Added to these natural causes, and far more influential in bringing about 

 this devastation, is the carelessness, improvidence and ignorance of man as is 

 exemplified in his treatment of the soil. Man has aided and abetted in the 

 prostitution of our natural resources : 



1. By clearing many thousands of acres which should have always remained 

 in forest. 



2. By shallow tillage. 



3. By tilling the same areas repeatedly in hoed or clean-culture crops. 



4. By high ridging or bedding as practiced for cotton and tobacco. 



5. By not maintaining humus in the soil. 



6. By failing to practice systematic and judicious rotation. 



7. By leaving soil bare of vegetation, particularly in winter and early 

 spring. 



8. By giving more attention to the tillage of the crop than to the tillage of 

 the soil. 



9. By neglect of the live-stock industry. 



10. By depending too much on man power and too little on farm work stock. 



11. By neglecting the large purebred for the small scrub. 



12. By failing to use up-to-date labor-saving farm implements. 



13. By dependence upon fertilizers to the neglect of the soil and of farm 

 manures. 



14. By failing to apply ordinary business principles to the business of farm- 

 ing. 



15. By neglect of mechanical means for the control of surface water. 



All of these are in varying degrees responsible for gullying and opposed to 

 good farm practice, and, all, so far as is practicable, must be utilized in bring- 

 ing about the desirable change. With conditions as they are, the first efforts 

 must be towards the control of surface water. The means to this end are : 



1. Deeper and better plowing, with better implements drawn by better ani- 

 mals. 



2. Terracing as a means by which the surplus water is allowed to leave the 

 field at as reduced a velocity as possible, and so that as great a proportion as 

 possible mav enter the soil. 



3. Level culture, that the water may be robbed of its velocity and momen- 

 tum by being spread uniformly over the surface. 



