320 FIELD AND GARDEN PRODUCTS 



POTATO. 



The term "potato," when not modified by an adjective, suggests 

 to the mind of an American the so-called potato (Solanum tuber- 

 osum) . When the name is modified by the word "sweet," reference 

 is made to a different plant, belonging to the morning-glory family 

 and known botanically as Ipomoea batatas. Attention is here di- 

 rected entirely to the Irish potato. 



Soil and Rotation. The potato is grown in every State and Ter- 

 ritory, and naturally on a great variety of soils. Indeed, it has been 

 grown on nearly every class of soils, but this fact does not minimize 

 the importance of selecting for the potato the kind of soil best 

 adapted to it. The ideal soil for this crop should be one so light as to 

 offer no great resistance to the enlargement of the tubers, so supplied 

 with organic matter as to be rather moist without being wet, and so 

 rich as to furnish an unfailing supply of fertilizing ingredients. A 

 rich, sandy loam abundantly supplied with organic matter and nat- 

 urally well drained is preferable. Stiffer soils may be rendered suit- 

 able for the potato by drainage and by the incorporation of farm 

 manures; or better, by plowing under green crops. Very heavy clay 

 should be avoided if the farm contains any lighter soil. Recently 

 cleared ground suits the potato. Sandy soils, if not too subject to 

 drought, may be fitted for this plant by the addition of organic mat- 

 ter. It is claimed that potatoes grown on sandy land are of better 

 quality than those grown on stiffer soil. 



The potato requires a rich soil, but even more important than 

 natural fertility is a proper mechanical condition of the soil. Artifi- 

 cial fertilizers may be substituted in part for natural fertility, but 

 they are effective only when the soil is in such a condition as to fur- 

 nish a constant supply of water. The potato should have the best 

 soil on the farm, since it is more exacting in this respect than the 

 other staple crops and since the product of an acre is generally of 

 greater value. The success of the potato is largely dependent on the 

 crops preceding it in the rotation. If clover, cowpeas, or other leg- 

 uminous plant is grown just preceding potatoes, its stubble furnishes 

 organic matter and adds to the store of available nitrogen in the soil. 

 Corn after sod frequently precedes potatoes, and this is generally re- 

 garded as the best rotation. 



Rye is sometimes sown in late summer or fall and plowed under 

 so as to lighten a heavy soil. Buckwheat and other plants have also 

 been used for the same purpose. On light soils and in rather mild 

 climates, crimson clover for green manuring may advantageously 

 take the place of rye -where early planting of potatoes is not specially 

 desirable. One year, or at most two years, is as long as a field should 

 be devoted to continuous potato culture, although this crop is some- 

 times grown for more than two years in succession on the same land. 

 This latter course taxes heavily the fertility of the soil and necessi- 

 tates liberal manuring; moreover it involves considerable risk of in- 

 jury from fungous diseases, especially from potato scab. A clean 

 crop of potatoes can not, as a rule, be grown on land which in the 

 preceding year produced scabby tubers. The germs of the disease 



