BUREAU OF PLANT INDUSTRY. 305 



Relation of acidity of soils to grazing plants. — In the progress 

 of the cooperative experiments between the Forest Service and the 

 Bureau of Plant Industry on the artificial reseeding of denuded 

 grazing lands in the National Forests, it had been found in 1908 and 

 1909 that the failure of certain forage plants on certain experimental 

 areas could not well be attributed to improper conditions of moisture 

 and temperature. On the suspicion that the conspicuous differences 

 of success or failure might have been caused by differences in the 

 acidity of the soil, a study of the acidity of these areas was made 

 in 1910, with wholly conclusive results. It was found that the areas 

 on which Kentucky bluegrass and timothy failed were acid and that 

 on these same areas redtop grew with great success. It was found, 

 on the other hand, that the areas on which redtop made a poor growth 

 and timothy and Kentuclry bluegrass succeeded were neutral or 

 slightly alkaline in their chemical reaction. It is clear from the 

 season's study that acidity of the soil is a factor of the greatest im- 

 portance, hitherto unconsidered, in the seeding of these mountain 

 grazing lands. Hereafter experimental sowings will be made with 

 reference to conditions of acidity as well as those of temperature and 

 moisture. 



Fortunately, nature herself has furnished a guide to the acidity of 

 these areas. There are certain wild plants which grow only on acid 

 lands, others which grow only on neutral or alkaline lands, and the 

 presence or absence of these indicative plants is an excellent practi- 

 cal guide for field work. The most trustworthy indicators of acidity 

 are various plants of the blueberry and heather families, especially 

 the species of the genus Vaccinium, known in New England as blue- 

 l3erries, but in the region of most of the National Forests called^ 

 huckleberries. 



Domestication of the blueberry. — A report entitled "Experi- 

 ments in Blueberry Culture," by Mr. Frederick V. Coville, has been 

 prepared and is now in press as Bulletin No. 193 of this Bureau. The 

 writer has found by experiment how blueberries differ from ordinary 

 plants in their method of nutrition and in their soil requirements, 

 and by means of this knowledge he has worked out a system of pot 

 culture, under which these plants attain a development beyond all 

 previous expectations. There is good prospect that the application 

 of the loiowledge thus gained will establish the blueberry in field 

 culture and that ultimately improved varieties of these plants will 

 be grown successfully on a commerical scale. The blueberry will 

 grow successfully only in acid soils. The most promising situations 

 for experiments in the field culture of the blueberry are either peat 

 bogs or sandy uplands treated with upland leaf peat. The full 

 results of the investigation of blueberry culture are given in the 

 bulletin referred to. 



BoiANY of the economic GRASSES. — The botanical studies of 

 grasses have continued in charge of Mr. A. S. Hitchcock, Systematic 

 Agrostologist. During the past 3'ear the work on the genus Pnnicum, 

 which is the largest genus of grasses in North America and contains 

 such important economic species as hog-millet. Para grass, Guinea 

 grass, and Colorado grass, as well as several sand binders, has been 

 completed and prepared for publication. Memoranda regarding val- 

 uable grasses found in different foreign countries are in preparation 

 73477°— AGR 1910 20 



