68 CULTIVATION AND IRRIGATION 



the grower depends upon the rains to produce his crop. 

 When hills are thrown up there is a greater amount of sur- 

 face soil exposed to the sun, and, consequently, the evapora- 

 tion of the moisture is greater. 



The first cultivation after the plants are up and the 

 rows can first be distinguished is with the harrow, running 

 lengthwise of the rows, being careful that the horses are 

 kept in the middle, so they will not trample on the plants. 

 This harrowing will not injure the tops and is the best culti- 

 vation the plants ever get. 



After the first cultivation with the harrow, when the 

 plants are up two or three inches, the cultivator is used. 

 On a small farm, where one-horse cultivation is practiced, 

 such an implement as the five-tooth cultivator best serves 

 the purpose. It will keep the surface of the soil fine and 

 mellow. It is wise to use the small sized teeth at first, so 

 too much dirt will not be thrown against the tops. However, 

 cultivate quite deeply. Always cultivate as closely to the 

 rows as possible without injuring or covering them with 

 dirt. After the first cultivation it is well each time to culti- 

 vate farther from the plants than the preceding cultiva- 

 tion, as the tubers are forming, and when the feed roots are 

 broken a certain per cent of vitality is taken from the grow- 

 ing plant. 



After irrigation, or after a rain, when the soil becomes 

 dry enough not to stick, it should be thoroughly cultivated, 

 and particularly well if the soil is inclined to bake or crust. 

 If the soil is fouled well with weeds or weed seed, the more 

 frequent and thorough the cultivations the less hand work 

 is needed. It is impossible to state definitely the number of 

 cultivations needed in the growth of a crop of potatoes. The 

 climatic conditions, the character of the soil, and the amount 

 of weeds determine the frequency of cultivations needed. It 



