400 GRASSES AND HOW TO GROW THEM. 



Prominent among the influences that favor such ero- 

 sions are: 1. Unevcnness in the surface of the land. 

 The steeper the descent, the more easily does the soil 

 moved downward. '1. The sandy character of the soiL 

 The finer the sand, the more easily does it move. 3. 

 The frequency and violence of the precipitation. Areas, 

 where violent thunder storms occur or occasional cloud- 

 bursts, are much liable to suffer from erosion. 4. Lack 

 of porosity in the subsoil which prevents the quick de- 

 scent of w^ater in the soil, and the nearer the hard sub- 

 soil comes to the surface, the greater is the loss of sur- 

 face soil. 5. Lack of vegetable matter in the soil. The 

 less of this in the soil, the less the water which it ab- 

 sorbs and the less is the obstruction to the removal of 

 soil particles. 



Important among the counteracting and preventive 

 influences are the following: 1. Ploughing deeply so 

 that the absorptive power of the ground will be in- 

 creased. 2. Making jDarallel surface drains at such dis- 

 tances as may be deemed proper along the sides of hills 

 to arrest and carry descending water along rather than 

 down the hill. 3. Constructing underdrains down the 

 depressions laid not far frcnn the surface and of con- 

 siderable capacit}' to aid in carrying away the water. 

 4. Laying such lands down to permanent pasture and 

 maintaining them as such. 5. Planting them with for- 

 est trees. Where such lands are not to be planted to 

 forest, the aim should be to keep them in i)ermanent 

 pasture. 



Tlie best grasses for such ])asture in tlu^ Xorthwest 

 is Pussian brome ; in the I^^orth, a mixture of Kentucky 



