IRRIGATION OF FIELD CROPS. 167 



ing the cultivation lias been carefully attended to. If 

 the soil is exceptionally dry and warm, however, irriga- 

 tion may occur every ten days after a month from the 

 transplanting, but no moisture to the root is needed 

 after the plants are topped. In Arid America the leaves 

 need artificial sprinkling to produce salable fiber. The 

 ordinary fruit tree sprayers may be used and the plants 

 given two or three light showers in the early evening 

 after the plants begin to ripen. This will supply the 

 deficiency in air moisture and cause the fibers to thicken 

 and become more solid. 



Potatoes. Here is something that requires scien- 

 tific irrigation. The ground intended for an irrigated 

 crop should be a smooth piece, having sufficient 

 slope to make the water run freely between the rows. 

 It should be plowed eight inches deep, or more, and 

 then harrowed and dragged until the soil is firm through- 

 out and thoroughly pulverized on the surface. Lay off 

 the ground in rows three and one-half feet apart with a 

 corn marker, or a small shovel which will make a shallow 

 furrow, the rows running the same way the ground 

 slopes, if it is not too steep. A slope of seven to ten 

 feet to the mile gives good results. The distance apart 

 in the rows depends upon the variety. If the Early 

 Ohio, which grows the smallest vines of any variety, be 

 used, I would advise planting ten inches apart in the 

 row. If the Peach Blow, which grows the largest vines 

 of any variety, be used, I would advise a distance of 

 twenty-one inches apart. The rows should be from 

 three feet to three feet six inches apart. The closer you 

 have the rows, and yet be able to work with horses con- 

 veniently, the better, because, the more compact the mat 

 of tops of the vines, the better the ground will be pro- 

 tected from the direct rays of the sun so that, after 

 irrigation, the moisture may be retained in the ground, 

 as the potato delights in a cool, moist soil. Cover by 



