HANDLING THE SOIL 41 



Harrowing. — The purpose of harrowing is to put the 

 ground in good condition to receive the seed. After the 

 plowing has been done there are many small clods that can 

 be easily broken if a harrow is dragged over the land. If the 

 land plowed has been sod, it will be necessary to stir the 

 plowed ground to break up the roots and make fine soil to 

 cover the seed. Sometimes, also, after plowing there come 

 heavy rains which beat down the land so hard that harrowing 

 is necessary to loosen it. Besides putting the soil in shape to 

 receive the seed, harrowing helps to warm the soil by loosening 

 it so that the warm air can circulate through it. x\t the same 

 time this loosening and fining the surface aids in keeping the 

 moisture in the lower soil from being evaporated at the sur- 

 face. Making the soil fine lets more plant food become 

 available for the plants. So it can be seen that harrowing is 

 also important. 



There are several kinds of harrows and each has its par- 

 ticular usefulness. 1. The spike-tooth or smoothing harrow 

 has a wooden or iron frame into which iron teeth are fixed. 

 These teeth can be made to stand straight or to slant as de- 

 sired by means of a lever. It is usually made in sections. 

 This kind of harrow is most extensively used. It is good to 

 break clods, loosen the soil when not too hard, and to level 

 down uneven land. Its most important use is for pulverizing 

 and levelling the surface soil. 2. The spring-tooth harrow 

 has curved strips of steel fixed into a frame. These can be 

 regulated by means of a lever also. This kind of harrow is 

 useful mainly for loosening up ground that has become 

 packed. It needs to be followed by a spike- tooth harrow to 

 level down the little ridges left. 3. The acme or colter har- 

 row is made of a number of sharp blades, like corn knives. 



