This section is from the book "The Potato: A Compilation of Information from Every Available Source", by Eugene H. Grubb, W. S. Guilford. Also available from Amazon: The Potato: A Compilation Of Information From Every Available Source.
Too much attention to the fitting of the soil for the crop can hardly be given, for no amount of after tillage can overcome neglect in preparation.
Deep and thorough plowing and harrowing, so as to make a perfect seed bed, not only establishes an earth mulch so as to prevent the loss of moisture of the spring rains, but it so fines the soil that the plant food contained in it becomes accessible to the growing plant. The conservation of moisture by frequent tillage is not understood or practised as it should be. The old notion that potatoes should be hilled and that tillage should cease as soon as the potato is in bloom, is wrong for most situations. Hilling is frequently practised so as to keep the tubers from becoming exposed to the sun; that is not necessary if the soil is properly prepared. On hard, compact soil the potato will, because of less resistance of the soil, push out of the ground. This will not happen in deeply worked land.
The proper preparation of a soil for the potato crop is a matter of years and not a single season. A soil, in order to do the best must be in excellent state of tilth and a high state of fertility. Such conditions can only be obtained by careful forethought and planning. Frequently soil is not plowed deeply enough. It is very common for people to speak of plowing seven, eight, or even nine inches, but most men would be surprised if they were to apply a rule to see how much short of this depth the plow actually goes below the actual level of the field. Many men who think they are plowing seven or eight inches deep are only plowing five inches. If this shallow plowing has been practised it is bad management to suddenly deepen the plowing, as this brings too much of the subsoil to the surface in a single plowing.
Good potato land may be handled in a three or four year rotation - potatoes, grain, grass one or two years, and then potatoes again, in some such way as the following: Land which is used for potatoes should, immediately after harvesting of the crop, be treated to a liberal application of farm manure, if it can be obtained, and plowed with lap furrow. The plow can well run an inch deeper than it did the preceding year when the land was prepared for potatoes. In the spring the soil will have crumbled by the frosts, and should then be thoroughly worked by frequent harrowings with some such tool as a disk or spading harrow. It should then be smoothed with an Acme harrow, or some other tool, and seeded to grain. If it is designed to grow only a single crop of grass, it is best at the time of seeding to sow clover with the grain. If, however, it is designed to remove two crops of grass, it can be seeded with a mixture of clover and timothy. The grain crop will be harvested the first year; the second season the crop will be chiefly timothy; the third it will be timothy and clover, and at the end of the two or three years, whichever plan is followed, there will be in the field in the fall a good stand of second growth clover. This should not be cut or fed, but should be plowed under, and this is all the more important if the piece has not been treated with farm manure. This fall plowing should be with lap furrow and the following spring it should be thoroughly worked with the disk and smoothing harrows in order to get ready for planting.
It may in many situations be desirable to follow the grass crop with corn, and then follow with potatoes. The same thorough preparation will be of advantage to the corn crop. The land for the corn should be liberally fertilized. Farm manure will be again used in this part in the rotation to advantage. The corn must be overfed in every way so that the land will be in a higher state of fertility at the end than at the beginning of the season. If corn enters into the rotation, fall plowing should be again practised, and the following spring the land should be thoroughly worked. The best possible seed bed should be prepared, so that the soil will be light and thoroughly pulverized to a depth of five or even six inches. In a soil thus prepared the planter will run easily."
In the senior author's trip to Europe in 1910 he found all of the best growers in Great Britain and Germany using nothing but whole seed. He did not visit a grower abroad who used cut seed. He secured a shipment of a ton of very select seed the from Earl of Rosebery's Dalmeny Farms, and George Sinclair, the farm manager, advised planting them whole, even though they cost $200 a ton laid down at Carbondale, Col.
In cutting seed, especially where soils are apt to be infected with fungous disease, the "armor" of the potato is broken in cutting and the tender tissue is exposed.
Farmers' Bulletin No. 92" of the United States Department of Agriculture contains the following:
As a recent bulletin of the New York Cornell Experiment Station shows, the average yield of potatoes in the United States is far below what it should be. This bulletin states that 'the average yield of potatoes throughout New York is not more than one half what is should be and what it would be were better methods practised.' This low yield is not due, as a rule, to poverty of the soil, because 'all soils of ordinary fertility contain sufficient potential plant food to produce abundant crops,' and a part of this potential plant food can be made available for the use of plants by tillage, and drainage, if necessary. The experiments of the Cornell station, which have now covered four seasons, were planned with a view to learning what superior tillage and care would do in the way of unlocking the hoarded fertility of the soil and increasing the yield of the crops.
The soil on which the potatoes were grown has been continuously under crop without fertilizers since the winter of 1893-94, except that cover crops of rye, crimson clover, or wheat, to be turned under in the spring, have as a rule been grown. But the growth of these has necessarily been so small and the cropping so intensive that the soil is beginning to show a deficiency of humus, indicated by its tendency to become hard and compact under beating rains; for 'in order to keep a soil permanently in good physical condition, it is absolutely necessary that organic matter be returned in some way, either by green manuring or the use of barn manures. '