98 



MANUAL OF GARDENING 



but in different degree. A covering of sawdust or leaves or 

 dry ashes will prevent the loss of moisture. So will a cover- 

 ing of dry earth. Now, inasmuch as the land is already cov- 

 ered with earth, it only remains to loosen up a layer oi; stratum 

 on top in order to secure the mulch. 



All this is only a roundabout way of saying that frequent 

 shallow surface tillage conserves moisture. The comparatively 

 dry and loose mulch breaks up the capillary connection be- 

 tween the surface soil and the under soil, and while the mulch 

 itself may be useless as a foraging ground for roots, it more than 

 pays its keep by its preventing of the loss of moisture ; and its 

 own soluble plant-foods are washed down into the lower soil by 

 the rains. 



As often as the surface becomes compact, the mulch should 

 be renewed or repaired by the use of the rake or cultivator or 

 harrow. Persons are deceived by supposing that so long as 

 the surface remains moist, the land is in the best possible condi- 

 tion; a moist surface may mean that water is rapidly passing 

 off into the atmosphere. A dry surface may mean that less 

 evaporation is taking place, and there may be moister earth 

 beneath it; and moisture is needed below the surface rather 

 than on top. A finely raked bed is dry on top; but the foot- 

 prints of the cat remain moist, for the animal packed the soil 

 wherever it stepped and a capillary connection was established 

 with the water reservoir beneath. Gardeners advise firming the 

 earth over newly planted seeds to hasten germination. This is 

 essential in dry times; but what we gain in hastening germina- 

 tion we lose in the more rapid evaporation of moisture. The 

 lesson is that we should loosen the soil as soon as the seeds have 

 germinated, to reduce evaporation to the minimum. Large 

 seeds, as beans and peas, may be planted deep and have the 

 earth firmed about them, and then the rake may be apphed to 

 the surface to stop the rise of moisture before it reaches the air. 



Two illustrations, adapted from Roberts's Fertility," show 



