204 SEEDING AND PLANTING 



only serves as a mulch to decrease the loss of soil moisture through 

 evaporation and lessens the danger of erosion but by its decay 

 adds materially to the organic richness of the soil (Fig. 34). 



The amount of litter on the surface and organic matter in the 

 mineral soil is, however, sometimes so great immediately after a 

 stand has been felled that it is inimical to direct seeding. Ger- 

 mination is always best in mineral soil. When direct seeding fol- 

 lows clear-cutting, therefore, it should be delayed until the organic 

 matter has partially decomposed or the area should be cultivated 

 in order to expose the mineral soil. It is sometimes advisable to 

 burn over the area immediately before seeding. This is particu- 

 larly true when there is an excess of organic matter and when 

 the loss from burning will be more than compensated by the 

 exposure of the mineral soil and by the supply of plant food imme- 

 diately liberated. 



20. Treatment of Areas Covered with Herbaceous Vegetation 



Idle farm lands, denuded lands subject to frequent fires, 

 and stands of open timber usually have a more or less rank 

 surface growth of grass, ferns, or other herbaceous vegetation. 

 It is nearly always desirable to burn over such areas in the late autumn 

 or early spring while the dried grass and other herbaceous material is 

 in suitable condition for burning. This procedure facilitates re- 

 generation and reduces the danger from insects and other pests. 

 The advantages usually more than compensate for the loss to the 

 soil of the material burned. The ash, in providing immediately 

 a small amount of available plant food, is often of advantage. 



When the soil is covered with a thick matting of grass it may 

 be necessary to remove the sod before the regeneration is under- 

 taken. This can be done by plowing. Young plants make 

 much more rapid growth on plowed land and the loss during 

 the first few years is less. Whether this is always of advantage 

 is a debatable question. In some cases it appears to be followed 

 by evil effects, particularly where the trees are closely spaced. 

 Thus, white pine planted in plowed fields on first quality sites 

 usually grows rapidly and evenly. As the canopy closes, the in- 

 tensity of the competition causes all the trees to suffer alike, and 

 the ultimate result is very disastrous unless thinning is begun 

 very early. On the other hand, when the trees are set on un- 



