68 



Nature-Study Agriculture 



Proper 



for the capillary water to reach them. (Exp. 3.) In 

 cool, wet weather, however, seeds need the surface warmth 

 which the sunshine supplies, and they will rot if too 

 deeply covered. The looser and drier the soil, the 

 deeper the planting should be. The usual depths j:or 

 planting are : clover and grass seeds % to i^ inches ; 

 wheat, oats, etc., i-g- to 3 inches; beans, i inch; peas 

 and corn, 2 to 4 inches. The smaller depths above 

 given are for heavy, moist soils ; the greater depths are 

 for light, dry soils. 



Planting too thickly often accounts for poor results. 

 ^ ver y c ^ ose together, plants interfere with each other's 

 of planting growth and become weak and spindling, just as they do 



too thickly f 



if they are crowded by weeds. If plants come up too 

 thickly they should be thinned at once, before they 

 begin to crowd each other. In doing this, keep in mind 

 the size that the plant will have when full grown. Large 

 seeds are seldom planted too thickly ; but great care has 

 to be used in planting small seed like that of turnips. 

 One good way to handle such seed is to mix it with fine, 

 dry sand or dust before planting. Another method 

 often employed with cabbage, onion, and lettuce seed 

 is to sow it thickly in boxes of earth and transplant 

 before the plants are big enough to crowd each other. 

 In China, where labor is cheap and land is scarce, this 

 method is employed in raising rice. 



Propagation by cuttings. A " cutting " or " slip " 

 is a piece of a small branch or twig planted to take root. 

 Even a leaf of some plants will take root and grow 

 (Fig. 46). Most of our house plants, and roses, and such 

 fruit plants as currants and grapes, are propagated by 



