Nj. 6. DEPARTMiiNT OF AGRICULTURE. 733 



face work. Where only surface work is wanted, the spring tooth is 

 excellent. The wheel-cultivator is used until the vines till much of 

 the middles, and then the one-horse cultivator comes into use. The 

 latter implement, going once in the middle, cannot do as good work 

 as the two-horse cultivator while plants are small. It does not give 

 the close hoeing to each hill that is necessary in good work. But 

 when the vines shade the row and close work is no longer possible, 

 the oiie-horse iiiiplement, with wheel to regulate depth, is nearly 

 perfect. The object of all this later cultivation is to preserve mois- 

 ture by keeping the surface two-inches of the soil loose, and care 

 must be exercised that the plant roots in the moist soil below the 

 mulch are not torn by the cultivator hoes. The thing to do is to 

 give the potato plants a chance to use the food in the soil. The 

 ground has been made loose as late in the season as is consistent with 

 root growth, and our business then is to keep the moisture in that 

 ground, and to let the plant roots use it in storing up food for them- 

 selves. Carelessness in matter of diepth of late cultivating may rob 

 a plant of much of its ability to gather food. 



Laying Potatoes liy. — Formerly we heard much about 'laying po- 

 tatoes by." This work then consisted of running a very broad single 

 shovel through the middle, throwing the soil upon the row and ridg- 

 ing it. ^^'hen this had been done, cultivation was at an end, because 

 the ground was up in ridges and nothing more could be done. Now- 

 adays, the potatoes ''lay" themselves "by" when they make such a 

 growth of vine that they do their own mulching of the field, and we 

 cannot get a cultivator through the middles. The only time to cease 

 tillage of potatoes is when the vines cover the ground. If the plant- 

 ing has been deep, in soil made properly loose by use of huinus, the 

 potatoes form under the dry soil mulch, and they do not come to 

 the surface no matter how flat it is. When a crust is formed in the 

 held by a rain, the right thing is to break it before it hardens, if the 

 vines are not down upon it, preventing such work. The period of 

 blooming has naught to do with determining the time to cease stir- 

 ring the surface soil, except that one should have plants by that time 

 so large that little more tillage can be given. 



In all this we are assuming that the potato rows should not be 

 ridged. Let us reason together. We know that the sweet potato 

 is the opposite of the white j)otato in that it wants heat and not a 

 great degree of moisture. Hence we learned to make ridges for 

 them. The ridge increases the area of surface exposed to the hot 

 air, and in the north that suits the heat-loving plant. The white 

 potato wants the cold of the extreme northern States, as we know 

 from its productiveness in such sections of our country. It needis 

 a cool soil for its roots, and hence we learn to keep our land cool and 

 moist by exposing no more of it to the sun's rays than is necessary — 



