404 FIELD CROPS 



sandy loam soils are especially desirable for producing 

 smooth, dean potatoes of high quaUty. Such soils, how- 

 ever, are quickly exhausted, unless kept up by the rotation 

 of crops and by the application of manure. Any soil, to 

 produce a good crop of potatoes, should be well suppHed 

 with vegetable matter, and be rich and melloAv to a consider- 

 able depth. 



519. Manures and Fertilizers. Stable manure is one of 

 the most desirable fertilizers for potatoes. It not only fur- 

 nishes the necessary plant food, but helps to loosen the soil 

 and to hold moisture, providing conditions very favorable for 

 potatoes. On ordinary soils, a dressing of from 8 to 15 loads 

 of stable manure to the acre, well-mixed with the soil, is a 

 suitable appUcation for the crop. Potatoes use much potash, 

 but most soils are well supplied with this element. When 

 commercial fertilizers are used, a complete fertilizer con- 

 taining from 2 to 4 per cent of nitrogen, 6 per cent of phos- 

 phoric acid, and 8 per cent of potash, is usually applied. 

 Five hundred pounds or more of this fertilizer is applied 

 to the acre, the rate depending upon the condition of the soil. 

 In the South, where soils are subject to considerable washing 

 and loss of fertility during all or nearly all the j^ear, larger 

 appHcations are usually made, often from 1,000 to 2,000 

 pK)unds to the acre. On some of the lighter types of soils, 

 or where leaching is at all likety to take place, the fertilizers 

 are often added during the growing season. On account of 

 the high prices of all fertilizers now prevailing (1918), smaller 

 applications than usual are being made particularly of potash. 



GROWING THE CROP 



550. Preparing the Land. Soil for potatoes should, as 

 a rule, be plowed deep, from 8 to 10 or 12 inches on the better 

 soils. It is not desirable, however, to plow an extremely light 

 soil so deep, unless it has been heavily fertilized with stable 

 manure, and the manure thoroughly mixed with the soil. 



