. Bulletin. 1901-13. Agriculture; Agriculture. IH MKTIK^DR TTSED FOR CONTROLLING SAND DUNEfl. coast just l)a(*k of the strand which presents conditions iinfavoraf)l(' to forest growth. Here it is !iecessary to liold tlie sand in phice jx'nna- nently b}' means of the grass. To do this recjuires constant super- vision. Through various causes })are spaces are likely to occur whieh must be replanted to prevent the formation of blowouts. Sometimes the bunches nuist be thinned, as the presence of two large adjacent bunches may cause the wind to draw through between them and form a .Strang
. Bulletin. 1901-13. Agriculture; Agriculture. IH MKTIK^DR TTSED FOR CONTROLLING SAND DUNEfl. coast just l)a(*k of the strand which presents conditions iinfavoraf)l(' to forest growth. Here it is !iecessary to liold tlie sand in phice jx'nna- nently b}' means of the grass. To do this recjuires constant super- vision. Through various causes })are spaces are likely to occur whieh must be replanted to prevent the formation of blowouts. Sometimes the bunches nuist be thinned, as the presence of two large adjacent bunches may cause the wind to draw through between them and form a .Strang /Jf - f-,-f*'> â ' ''^^ Fig. 7.âRepiiiring a small breach in a barrier dune by plaining grass. On the Kurische Nehrung in Prussia and along the southwest coast of France it has been found advisable to form an artiticial protecting dune extending all along the sea in front of the forest (1*1. VI, tig. 1). This dune is produced l)y accunudating the sand rapidly so as to form a long ridge (tig. tl). For this purpose brush fences, which consist of rows of brush or rough branches driven into the sand tirndy but rising above the surface al)out 30 inches, are used. The tops should be on a level. Two such rows are placed about G feet apart. These fences allow the wind to pass through, but reduce its velocity, and hence sand is deposited within and on both sides. When the sand has reached the top of the fences, a second pair is placed above. When a ridge has been formed, l)each grass is planted in rows parallel to the crest. At first, plantings are made along the slopes and a short distance in front toward the strand. As the sand accunmlates, the grass is planted far- ther to the windward. Finally the protecting dune assumes a com- paratively permanent form, with a long slope to windward (toward. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfec
Size: 4393px × 569px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookpublisherwashingtongovtprintoff, booksubjectagriculture
