42 WINDBREAKS. 



groves of trees, and other factors which prevent this movement of 

 the soil, is described in detail, and a systematic planting of wind- 

 breaks for the protection of fields is very strongly urged. 



The sand hills of Nebraska furnish another striking example. In 

 years of plentiful moisture many fields in that section can be culti- 

 vated profitably, yet at any time winds may begin to move the soil 

 and the "blow-out" may continue until the water table is reached. 

 Unfortunately, the farmers in this region have never fully appre- 

 ciated the value of windbreaks, and are again cultivating areas which, 

 in dry years, will prove to be valueless without protection from 

 winds. 



Damage of this sort does not stop with the taking up of the soil 

 from one field, but may be quite as great in another field where the 

 soil is deposited. 



The sand hills south of the Arkansas River in Kansas have been 

 built up, it is said, from sand blown out of the bed of that river at 

 times of low water. Similar conditions exist in the Columbia River 

 Valley in Washington and Oregon, where the sands from the river 

 are picked up and carried on to adjoining fields, with the result that 

 crops are completely buried and much damage is done to fruit (PI. 

 XII). In a case of this sort the larger particles of sand are rolled 

 along the ground rather than lifted into the air. In the Columbia 

 River Valley a simple strip of grain planted near the bank of the 

 river has sometimes been found to be very efficient in catching the 

 sand. Of trees planted in this region the Lombardy poplar has 

 been found best adapted to the situation, and very soon forms a 

 protective barrier about orchards and grain fields. Railroads are 

 compelled to construct numberless "hurdles" or low board fences 

 to check the moving sand which threatens to bury their tracks. 

 Willows have in some cases been planted successfully and serve the 

 purpose as well as fences (PL XII, fig. 2). 



In the Arkansas River Valley, where there are extensive orchards, 

 it was early discovered that they must have the protection afforded 

 by hedges and belts of trees. Russian mulberry has proved very 

 valuable for this purpose, at the same time baiting the fruit-eating 

 birds, which would otherwise destroy the more valuable crop. 



It is commonly supposed that heavier soils are not likely to be 

 moved by winds to an extent to damage crops. In Marion County, 

 Kans., however, the movement of the soil, a moderately heavy fine 

 loess, 25 or 30 years ago threatened the usefulness of the farm lands 

 of that section. Soil drifts several feet deep can still be seen in 

 lanes and along roads, which were at that time protected by low 

 hedges or fences, w T hich formed traps. With the planting of many 

 hedges of osage orange the movement of soils ceased. 



