Windbreaks and Shelterbelts 



193 



belts, not counting those on farmsteads, 

 were planted by the Forest Service. 

 The Soil Conservation Service of the 

 Department of Agriculture (to which 

 the work was transferred in 1942) 

 planted 8,363 miles between 1934 and 

 1949 in its program on soil conserva- 

 tion districts. The Wisconsin State 

 Conservation Department furnished 

 stock and, with the Extension Service, 

 was responsible for establishing 5,942 

 miles of shelterbelts. In California, the 

 fruit-tree growers planted 2,000 miles 

 of belts to protect citrus orchards and 

 vineyards. In Indiana, truck garden- 

 ers have planted 100 miles on muck 

 land. Many more miles of shelterbelts 

 for which no published records are 

 available probably have been planted 

 in other States. 



THE FARM PLANTINGS before 1935 

 did not include the large numbers that 

 could also be classified as shelterbelts, 

 but landowners who were fortunate 

 enough to have them in the droughty 

 1930's had proof of their benefits. 

 Pioneer planters of shelterbelts and 

 windbreaks in the Great Plains had 

 little knowledge of how to make trees 

 live and only a meager knowledge of 

 the growth habits of the trees they had 

 to use. It is surprising, in view of those 

 handicaps, that even moderate success 

 was attained. 



Progressive farmers and orchardists 

 plant shelterbelts for two primary pur- 

 poses to control soil blowing and to 

 protect crops. Some southern Great 

 Plains cotton planters find it neces- 

 sary to replant two and three times 

 on the unprotected fields. Sugar-beet 

 farmers on sandy, irrigated fields in 

 the West frequently have a crop cut 

 off by drifting sand as it emerges from 

 the ground. The small-grain and corn 

 farmers have had similar experiences. 

 From the time that crops are well estab- 

 lished until they are ready for harvest, 

 they are constantly subjected to dam- 

 age or to destruction by soil drifting, 

 blow-down, firing by hot winds, loss 

 of soil moisture, or damage from frost 

 and sleet. Orchards are subjected to 



802062 49 14 



the same damages, but the greatest 

 benefits are realized from protecting 

 the trees during the pollination stage 

 and preventing wind damage to the 

 ripening fruit. 



Besides, properly located and ar- 

 ranged shelterbelts can do much to 

 beautify the landscape and act as snow 

 fences in winter, thus helping to keep 

 open highways and rural roads. 



Thomas T. Wilson, of the Manitoba 

 Department of Public Works, said that 

 planted snow traps can be consider- 

 ably cheaper than the usual slat-wire 

 snow fence. His data, based on 201.6 

 miles of caragana hedge, indicates a 

 prorated cost per mile for a year of 

 about $100, assuming an average effec- 

 tive life of 25 years for the planting. 

 Prorated costs of slat-wire snow fences 

 were about $225 per mile for a year, 

 assuming an average life of 20 years 

 for this type of fence. Hence, the cost 

 of the planted hedges is less than half 

 that of slat-wire snow fence. The com- 

 parison, of course, does not consider 

 the possible rental cost of the land the 

 caragana hedge may occupy, but in 

 places where a 200-foot right-of-way is 

 owned, this question is resolved. 



THE EFFECTS ON FIELD CROPS are 

 less distinct. A survey among Nebraska 

 farmers showed that 29 farmers rated 

 high the value of field shelterbelts, 

 although 18 had been unable to ob- 

 serve benefits. The average estimated 

 gain in production amounted to $43 a 

 year. In South Dakota, 27 farmers said 

 the crop gain was $60 a year per farm. 



A mistake made by some observers 

 is to note only that corn or small grains 

 growing at the edge of a field protected 

 by the belt is usually inferior to that 

 growing a few rods out in the field, 

 where, in fact, the greatest benefit 

 nearly always occurs. A fair compari- 

 son can be made only between both 

 of these zones and the distant part of 

 the field that has no protection. But 

 a large number of systematic measure- 

 ments throughout entire fields has 

 shown that sound comparison could 

 easily lead to differences of opinion, 



