90 



Where alfalfa is the foundation crop it is rather difficult to plow it up. 

 This is usually done by plowing the alfalfa when it is blooming, first shal- 

 low to a depth of 3 or 4 inches, in order to turn over the plant and cut off 

 the crown at that depth to expose the roots to the sun. This is followed 

 by a deep plowing in the fall which leaves the land in good condition for 

 the potato crop. 



New land is broken up in the fall previous to growing crops by plowing 

 deeply and allowing it to stand in that condition until spring when it is 

 either worked up by a shallow plowing 4 to 6 inches deep and then har- 

 rowed, or simply pulverized and worked up with a disk or spring tooth 

 harrow. 



3. Planting Potatoes. 



The time of planting varies with climatic conditions and the kind of 

 potatoes. Early potatoes are planted in the spring as soon as the frost 

 is out of the ground and when there is no danger of late hard frosts. Late 

 potatoes may be planted as late as the middle of June, but usually earlier 

 is more desirable, especially where there is a deficient water supply in the 

 late summer. 



The depth of planting depends on the condition of the soil and the kind 

 of potatoes. Early potatoes planted in moist retentive soil are placed 2 to 

 2^ inches deep; where the soil is not retentive and is dry, or where there 

 is danger of heavy frost, 4 inches is better. The rows are spaced 36 to 42 

 inches apart and the hills in the rows 12 to 15 inches apart; on rich land 

 they may be placed as close as 8 inches apart. 



The seed may be either whole or cut. Good size seed must be used. In 

 Colorado medium size whole seed as large as two ounces is preferred. 

 Four ounce potatoes are cut in two and six ounce potatoes in three. Pota- 

 toes raised on irrigated land are not considered the best for seed, and dry 

 land seed from Wisconsin, Minnesota or from non-irrigated land of Colo- 

 rado, are generally used in that State. It is important that the seed be 

 properly selected. A uniform size is desirable. Seed averaging 1 * ounces 

 in weight and spaced 12 inches apart in rows spaced 40 inches apart will 

 require about 1200 pounds of seed to the acre. 



For small areas the seed is placed in the furrow and pressed by hand, 

 then covered with plow or harrow. For large areas mechanical planters 

 drawn by a horse are used. They will open the furrow, place the seed, 

 cover it, and pack the soil. 



4. Cultivation. 



The cultivation should begin soon after planting. The first cultivation 

 between the rows which are indicated by the tracks of the planter, begins 

 a week after planting. This cultivation should be 8 or 10 inches deep in 

 order to well aerate the soil and kill the alfalfa which may have a tend- 

 ency to sprout again. The cultivator drawn by two horses, has four 

 shovels, two for each side of the row; they are 4 to 5 inches wide and 14 

 to 15 inches long. The cultivator is followed by a harrow. Cultivation is 

 continued with the harrow passed over the land in both directions once a 

 week, if possible, until the plants are 5 or 6 inches high. Shallow cultiva- 

 tions after each irrigation until the plants cover the ground is desirable. 



5. Quantity of Water Required for Potatoes. 



Experiments made by the Agricultural College of Utah on the relation 



