April, 1932] Agricultural Eesearch in N. H. 23 



apparent correlation between the amount of root growth and the 

 amount of top growth, although vigorous tops usually go with rapidly 

 growing root systems. 



The roots of trees in the open showed no growth from November 15 

 to April 1. The roots of a four-year-old tree kept in the greenhouse 

 grew approximately as fast in winter as in summer. 



Six-year-old trees averaged a root growth of 18 to 20 inches on sandy 

 soil and 5 to 10 inches on clayey soil. 



With four-year-old white pine set six feet apart on sandy soil, root 

 competition may be expected to start within five years after planting. 

 On a clayey soil it is delayed until about the tenth year. 



Failures in plantations should be replaced not later than one year 

 after the trees are set out, and the stock used should be of the same 

 age as that in the successful parts of the plantations. 



Investigation of a few roots of white pine, gray birch, red cedar, 

 and common juniper indicates that the white pine is best adapted to 

 invade the soil of abandoned pastures, and will ordinarily survive in 

 competition with these three species. Further work along this prob- 

 lem will include other trees and plants usually found on such sites. 

 (Hatch Fund) 



Formation of Forest Soils 



Rate of Deposition of Litter. Studies in the formation of forest 

 soils show decided variations in the rate at which litter is deposited 

 under different types of forest. Six months of preliminary investiga- 

 tion gave the following monthly accumulation in pounds per acre, dry 

 weight, for old conifers, mixed hardwoods, and gray birch : June — 

 189.69, 49.08, and 91.98, respectively, July— 152.12, 76.29, 195.36; 

 August— 144.65, 37.6, 939.52; September— 379.17, 101.19, 267.96; Octo- 

 ber — 1,254.23, 1,757.55, birch not measured ; November and December — 

 214.5, 201.18, birch not measured. (Hatch Fund) 



Acidity of Autumn Leaves. Least acidity of autumnal-colored leaves 

 was found in those of the species hop hornbeam. The aspens ranked 

 next, beech third, and others in the order given : black birch, gray birch, 

 red oak, white oak, Scotch pine, sugar maple, blue beech, Norway spruce 

 red maple, white elm, red pine, and white pine. Hop hornbeam, beech 

 and black birch would appear to be of some assistance in controlling 

 soil acidity under coniferous stands. (Hatch Fund) 



Mapping Land Uses 



A study of land utilization in the town of Durham was completed 

 by C. E. Walker and published in Bulletin No. 255. In addition, an 

 estimate of the timber and the distribution of age classes were in- 

 cluded. The study of the tillage and pasture uses was only prelimi- 

 nary. A similar mapping of the town of Fremont was also done, but 

 with particular emphasis on ownership and boundary lines. The two 

 studies indicate that comparatively large areas can be mapped for 

 approximately 10 cents per acre. This would include a rough estimate 



