Roots in Shelter-belt Influence on Farm Products

Abstract

In proportion as trees in shelter-belt increase in number, their roots come to compete keenly in growing, with more frequency of intrusion into arable land and with undue extension besides.
In case of uncultivation, a tree in wood-belt takes roots about 1.25 times its height, but plowing every year brings its growth not to exceed 0.8 time, while a cutting ditch cuts its expansion as short as 0.6 time its height.
Although enough moisture content of soil remains unduly decreased within the radius of a half time the tree height, it is not so insufficient as affects the tree when the roots increase its growth by 1.5 times.
The diminution of the amount of contained water in the ground is believed to be arisen from absorbing nutritious water by the roots, intercepting falling water by the leaves and branches horizontally stretched out, and small water-hold capacity by the soil composed of much organism.
As for wheat harvest at the east side of the shelter hedge, around the area 0.5 time its height away, 5% increase of the harvest is to be promised in the section where a ditch hinders the roots, compared with the harvest in the all over turned-up land.
The shelter-belt suffers damage by double fold influence of its own shade and roots, but the damage caused by the roots alone is supposed to be calculated about 5 or 6 percent of the whole.