82 BULLETIN 355, U. S. DEPARTMENT. OT- AGRICUL^UBE. 
humidity is higher than on hilltops and in which danger of storms is 
less are especially well suited for this crop. 
Sugar beets (Ref. No. 7, pp. 606-608). — With reference to fertility, 
sugar beets have essentially the same requirements as corn, though 
it is important to recognize the fact that this crop requires a great 
deal of hand labor. A highly fertile soil, comparatively free from 
weeds, is therefore even more desirable for this crop than for corn or 
cotton. There is a close connection between the climate and the 
sugar content of the beet. The most favorable conditions are those 
of relatively cool nights and of very clear, bright weather, especially 
during the ripening period. These two conditions are combined in 
the North and in the western prairie States, where the altitude is such 
as to produce cool nights. 
Potatoes (Ref. Nos. 7, pp. 598, 604; 10, p. 254).— While potatoes 
are similar to corn and sugar beets in their general requirements of 
plant food, their production on a large scale is chiefly controlled by 
conditions affecting: (1) Their quality and freedom from the dis- 
eases to which they are subject, and (2) the use of tools for planting 
and digging. The largest yields of this crop may be secured on rela- 
tively heavy soils which have high water-holding capacity and ordi- 
narily greater fertility, but on these soils the crop is subject to dis- 
eases and can not be planted or harvested as readily as on the lighter 
sandy loams which permit the use of the digger and do not bake or 
crack so as to allow sunburn. Hence, this crop is best grown on 
relatively light soils. When grown on heavier soils and in a region 
of heavy summer precipitation a ridged system of culture is best, 
but on the lighter soils and wherever summer rainfall is not excessive 
flat culture is preferable. 
Scab and other fungus diseases to which the potato is subject 
develop more often on soils of neutral or alkaline reaction than on 
those which are acid, and hence, as before stated, the use of lime for 
the correction of soil acidity is not desirable on the potato crop, or 
if used on land on which potatoes are to be grown it should be applied 
on the crops from one to three years before the potatoes are grown. 
Cabbage and celery (Ref. No. 7, pp. 625, 628). — These crops are 
similar in that they require large amounts of nitrogen, potash, and 
water for their growth. Muck soils meet the requirements in regard 
to nitrogen and water and require chiefly the use of potash fertilizers 
to meet the demands of these crops. 
Melons, cucumbers, tomatoes, etc. (Ref. No. 7, pp. 614-637). — These 
crops are similar", especially in that the} 7 require unusually warm soils 
and so are especially adapted to sandy loams. The fertility of these 
soils can be maintained only through the use of relatively large quan- 
tities of fertilizer, which should be applied in the form of organic 
matter, such as barnyard manure and dried blood, as far as possible. 
