THEORIES VERSUS FACTS
PERCY planned to walk to Blue Mound to take the three-thirty train
that Saturday afternoon; but Adelaide's parents both insisted that
she would willingly drive to the station, and the grandmother
discovered that she needed a certain kind of thread which Adelaide
could then also get at the store.
"Certainly," said Adelaide, with some merriment, "I always enjoy our
departing guests to the train."
"Very well," replied Percy. "If you must go to get the thread and
will permit me to be the coachman, I shall be satisfied, for you
will be home early."
"Then we will take the colts and buckboard, and I shall be home in
less than twenty minutes after your train leaves the station."
"I think I have missed several days of your beautiful 'Indian
Summer,' because of my trip to the North," Percy remarked to Mr.
West as they sat on the broad veranda waiting for the hour of two
thirty when the colts were to be ready for the drive.
"I wish you might have been with us while Professor Barstow was
here," replied Mr. West, "not only because of the mild autumn
weather we have had, but also because Professor Barstow has some
ideas about questions of soil fertility that are very different from
those you hold. He says a young man from Washington gave a lecture
at his college down in North Carolina, in which he informed them
that the cause of infertility of soils is a poisonous substance
excreted by the plant itself, and that this can be overcome by
changing from one crop to another because the excrete of one plant,
while poisonous to that plant, will not be poisonous to other plants
of a different kind. Thus, by rotation of crops, good crops could be
grown indefinitely on the same land without the addition of plant
food. He said that the soil water alone dissolved plenty of plant
food from all soils for the production of good crops, and that the
supply of plant food will be permanently maintained, because the
plant food contained in the subsoil far below where the roots go is
being brought to the surface by the rise of the capillary moisture,
and that there is in fact a steady tendency toward an accumulation
of plant food in the surface soil. He said that it is never
necessary to apply fertilizing material to any soil for the purpose
of increasing the supply of plant food in that soil. He admitted
that applications of fertilizers sometimes produce increased crop
yields, but that the effect was due to the power of the fertilizer
to destroy the toxic substances excreted by the plants, and this is
really the principal effect of potash, phosphates, and nitrates, and
also of farm manure and green manures. Humus, he said, is one of the
very best substances for destroying these toxic excrete although
they had some other things which were as good or better than any
sore of fertilizing materials. He mentioned especially a substance
called pyrogallol, which cost $2.00 a pound, and of course it could
not be applied on a large scale; but it was as good a fertilizer as
anything, although it contains nothing but carbon, oxygen, and
hydrogen, which, as you explained to me when you were here before,
the plants secure in abundance from air and water. This information
had been secured in the laboratories at Washington by growing wheat
seedlings in water culture for twenty-day periods."
"I have already heard something of those theories," said Percy, "but
I shall be glad to have you tell me more about them. As I understand
them, we need only to rotate and cultivate and our lands should
always continue to produce bountiful crops. Is that correct?"
"I understand that is the theory," replied Mr. West, "but I know it
is not correct for my grandfather used to grow two or three times as
much wheat per acre as I can grow, and I rotate much more than he
did. In fact I can grow only ten to fifteen bushels of wheat per
acre once in ten years, whereas he grew from twenty-five to forty
bushels per acre in a five-year rotation; and I don't see that there
is any particular connection between the growing of wheat seedlings
in small pots or bottles for a few twenty-day periods and the
growing of crops in soils during successive seasons. No, I don't
take any stock in their theories. I think they are _watered, _or
perhaps I should say _hydrated, _in deference to science. But I
would like to know about this question of plant food coming up from
below. That would be a happy solution of the fertilizer problem."
"It is true," said Percy, "that soluble salts are brought to the
surface in the rise of moisture by capillarity in times of partial
drouth; and in the arid regions where the small amount of water that
falls in rain or snow leaves the soil only by evaporation, because
there is never enough to produce underdrainage, the salts tend to
accumulate at the surface. The alkali conditions in the arid or
semiarid regions of the West are thus produced. But in humid
sections where more or less of the rainfall leaves the soil as
underdrainage the regular loss by leaching is so much in excess of
the rise by capillarity that soils which are not affected by erosion
or overflow steadily decrease in fertility even under natural
conditions, with no cultivation and no removal of crops. Of course
this applies at first only to the mineral plant foods, as phosphorus
potassium, magnesium, and calcium. While mineral supplies are
abundant in the surface soil, there may be a large acumulation of
organic matter and nitrogen, especially because of the growth of
wild legumes, which are very numerous and in places very abundant,
especially on some of the virgin prairies of the West. However, as
the process of leaching proceeds there comes a time when the growth
of the native vegetation is limited because of a deficiency in some
essential mineral plant food, such as phosphorus, or the limestone
completely disappears and soil acidity develops which greatly
lessens the growth of the legumes.
"Decomposition of organic matter begins almost as soon as any part
of the plant ceases to live, and there is certain to come a time
when the rate of decomposition and loss exceeds the rate of fixation
and accumulation; and from that time on the organic matter and
nitrogen as well as the mineral plant foods continue to decrease in
the surface, until finally the natural barrens are developed, such
as are found in different sections of the World and in some places
even where the rainfall is sufficient for abundant crops."
"Yes, Sir," said Mr. West. "I know that is true. I have visited
Tennessee and I know there are some extensive areas there of
practically level upland which have always been considered too poor
to justify putting under cultivation, and they are called the
'Barrens'."
"I know about those barren lands, too," said Percy. "Our teacher of
soil fertility in college told us that a farm is more than a piece
of the earth's surface. He said if we only wanted to get a large
level tract of upland where the climate is mild and the rainfall
abundant and where all sorts of crops do well on good soil,
including the wonderful cotton crop which brings a hundred dollars
for a thousand pounds, while corn brings forty dollars for a hundred
bushels,--well, he said we could go to the Highland Rim of Tennessee
where, according to analyses reported in 1897 by the Tennessee
Experiment Station, the surface soil of the 'Barrens' contains
eighty-seven pounds of phosphorus and the subsoil sixty-one pounds
of phosphorus per acre, counting two million pounds of soil in each
case. He said, if we didn't like that we might go into the Great
Central Basin of Tennessee or the famous Blue Grass Region of
Kentucky and find land that is still extremely productive and more
valuable than ever, even after a hundred years of cultivation, and
buy land containing from three thousand to fifteen thousand pounds
of phosphorus per acre."
"I know both of those sections very well," said Mr. West. "But
doesn't it seem strange that the scientists at Washington would
teach as they do? Why doesn't the plant food accumulate in the
surface soil of those barrens? Surely they have been lying there
long enough, with no crops whatever removed, so that they ought to
have become very rich. I wish I had known about their phosphorus
content so I could have told Professor Barstow. He was quite carried
away with the Washington theory."
"You ought not for a moment call it the 'Washington' theory," said
Percy; "and neither is it promulgated by scientists, but rather by
two or three theorists who are upheld by our greatest living
optimist. Science, Sir, is a word to be spoken of always with the
greatest respect. Of course you know its meaning?"
"Yes, I know it comes from the Latin _scire, _to know."
"Then _science _means _knowledge; _it does not mean theory or
hypothesis, but absolute and positive knowledge. Is there any
uncertainty as to the instant when the next eclipse will appear? No,
none whatever. Science means knowledge, and men are scientists only
so far as they have absolute knowledge, and to that extent every
farmer is a scientist.
"Nevertheless the erroneous teaching so widely promulgated by the
federal Bureau of Soils is undoubtedly a most potent influence
against the adoption of systems of positive soil improvement in the
United States, because it is disseminated from the position of
highest authority. Other peoples have ruined other lands, but in no
other country has the powerful factor of government influence ever
been used to encourage the farmers to ruin their lands."