An Experiment In Fertilizing Grapes
The New York Agricultural Experiment Station is experimenting with
fertilizers for grapes at Fredonia, Chautauqua County, the chief grape
region in eastern America. The experiment should be of interest to
every grape-grower from several points of view. It not only shows that
there are many and difficult problems in fertilizing grapes, but also
the results of the use of manure, commercial fertilizers and
cover-crops in
particular vineyard; it suggests the fertilizers to
be used and the methods of use; and it furnishes a plan for an
experiment by grape-growers who want to try such an experiment and
draw their own conclusions. An account of the experiment and the
results for the first five years follows:[10]
Tests at Fredonia.
"In the vineyard at Fredonia eleven plats were laid out in a section
of the vineyard where inequalities of soil and other conditions were
slight or were neutralized. Each plat included three rows (about
one-sixth of an acre) and was separated from the adjoining plats by a
'buffer' row not under test. One plat in the center of the section
served as a check, and five different fertilizer combinations were
used on duplicate plats at either side of the check. Plats 1 and 7
received lime and a complete fertilizer with quick-acting and
slow-acting nitrogen; Plats 2 and 8 received the complete fertilizer
but no lime; on Plats 3 and 9 potash was omitted from the complete
fertilizer combination; Plats 4 and 10 received no phosphorus; Plats 5
and 11, no nitrogen; and Plat 6 was the check. The materials were
applied at such rates that they provided for the first year 72 pounds
of nitrogen per acre, 25 pounds of phosphorus and 59 pounds of
potassium; and for each of the last four years two-thirds as much
nitrogen and phosphorus and eight-ninths as much potassium. The lime
was applied the first and fourth years in quantity to make a ton to
the acre annually. Cover-crops were sown on all plats alike and were
plowed under in late April or early May of each year. These differed
in successive years, but included no legumes. The crops used were rye,
wheat, barley and cow-horn turnips separately and the last two in
combination.
"The cultivation differed only in thoroughness from that generally
used in the Belt, the aim being to maintain a good dust mulch during
the whole growing season. Pruning by the Chautauqua System was done
throughout by one man, who pruned solely according to the vigor of the
individual vines and left four, two or three, or no fruiting canes as
appeared best. The vineyard was thoroughly sprayed, all plats alike.
"Low winter temperatures, affecting immature wood and buds caused by
unfavorable weather of the previous season, reduced yields materially
during two of the five years, and practically neutralized any
anticipated benefit from fertilizers. Following the first of these
low-crop years, came a season, 1911, in which favorable conditions,
acting upon vines left undiminished in vigor by the light crop of the
previous year resulted in heavy and quite uniform yields on all the
plats.
"The yields for the five years are shown in Table I; and a summary
showing the average gains from each treatment is given in Table II,
with the average financial balance after deducting the cost of
fertilizer application from the increased returns from the plats
receiving them.
TABLE I.--YIELD OF GRAPES (TONS PER ACRE) IN FERTILIZER EXPERIMENTS
=========================================================================
Plat. 5-year
No. 1909 1910 1911 1912 1913 avg.
-----+-------------------------+------+------+------+------+------+------
TonsTonsTonsTonsTonsTons
1 Complete fertilizer; lime 4.48 2.10 5.37 3.46 2.14 3.51
2 Complete fertilizer 4.76 2.21 5.71 4.30 2.83 3.96
3 Nitrogen and phosphorus 5.17 2.14 5.61 4.00 2.25 3.83
4 Nitrogen and potash 4.25 2.55 5.64 4.10 2.85 3.87
5 Phosphorus and potash 3.41 2.00 5.44 4.35 1.78 3.39
6 Check 3.38 2.10 5.32 3.60 1.24 3.12
7 Complete fertilizer; lime 4.69 2.38 5.62 4.80 3.04 4.10
8 Complete fertilizer 4.66 2.07 5.71 4.98 2.72 4.02
9 Nitrogen and phosphorus 4.99 2.04 5.35 4.89 2.61 3.97
10 Nitrogen and potash 4.79 2.26 5.91 4.89 3.07 4.18
11 Phosphorus and potash 4.99 1.87 5.03 4.21 1.97 3.61
=========================================================================
TABLE II.--AVERAGE INCREASE IN GRAPE YIELDS AND AVERAGE FINANCIAL GAIN
FROM FERTILIZER APPLICATIONS
N = nitrogen, P = phosphorus, K = potassium, Ca = lime.
Gains in tons per acre.
========================================================================
N, P, N, P, N, P. N, K. P, K.
K, Ca. K.
----------------------+---------+---------+---------+---------+---------
Tons Tons Tons Tons Tons
First plat of pair 3.51 3.96 3.83 3.87 3.39
Second plat of pair 4.10 4.02 3.97 4.18 3.61
---------+---------+---------+---------+---------
Average 3.80 3.97 3.90 4.02 3.50
Check plat 3.12 3.12 3.12 3.12 3.12
---------+---------+---------+---------+---------
Average gain .68 .85 .78 .90 .38
Average financial gain $5.82 $13.84 $14.05 $18.54 $6.99
========================================================================
From this last table the benefit from nitrogen appears quite evident
since every combination in which it appears gives a substantial gain
over the one from which it is absent. Phosphorus and potassium without
the nitrogen, lead to only a slight increase over the check; and lime
appears to be of no benefit. Financially, the complete fertilizer and
lime combination, the nitrogen and phosphorus combination and the
phosphorus and potassium combination failed to pay their cost in five
of the ten comparisons; the complete fertilizer was used at a loss
four times out of ten; and the nitrogen and potassium combination
three times out of ten. Lime had no appreciable effect on either vines
or fruit.
"No effect of the fertilizers on the fruit itself, aside from yield,
was shown for the first three years; but in 1912, and even more
markedly in 1913, the fruit from the plats on which nitrogen had been
used was superior in compactness of cluster, size of cluster and size
of berry. In 1912 also, when early ripening was a decided advantage,
the fruit on the nitrogen plats matured earlier than that on the
check plats. In 1913 the favorable ripening season and the smaller
crop tended to equalize the time of ripening on all plats. The grapes
on the phosphorus-potassium plats were better in quality than those in
the check plats but not as good as those on the plats where nitrogen
was used.
"Other indexes also show plainly the benefit from nitrogen in this
vineyard; for size and weight of leaf, weight of wood produced and
number of fruiting canes left on the vines were all greater where
fertilizers, and particularly nitrogen, had been used. The three-year
averages (1911-1913) of the measurements for these characteristics are
shown in Table III:
TABLE III.--COMPARATIVE PRODUCTION OF LEAVES, WOOD AND FRUITING CANES
ON GRAPE VINES DIFFERENTLY FERTILIZED
(Averages for three years.)
=======================================================================
FERTILIZER APPLICATION LEAF WOOD FRUITING
WEIGHT[11] PRUNED[12] CANES LEFT[13]
----------------------------+------------+------------+----------------
Grams. Lbs.
Complete fertilizer; lime 1,033 1,295 2,468
Complete fertilizer 1,010 1,367 2,609
Nitrogen and phosphorus 1,047 1,272 2,585
Nitrogen and potassium 1,069 1,401 2,646
Phosphorus and potassium 964 1,086 2,326
Check 930 915 2,110
=======================================================================
Cooeperative experiments.
"In order to secure information as to the behavior of fertilizers on
the different soils of the Grape Belt, cooeperative tests were carried
on in six vineyards owned, respectively, by S. S. Grandin, Westfield;
Hon. C. M. Hamilton, State Line; James Lee, Brocton; H. S. Miner,
Dunkirk; Miss Frances Jennings, Silver Creek; and J. T. Barnes,
Prospect Station. The soil in these vineyards included gravelly loam,
shale loam and clay loam, all in the Dunkirk series, and the
experiments covered from two to two and a half acres in three cases
and about five acres in each of the other vineyards. The work
continued four years in all but one of the experiments, which it was
necessary to end after the second year.
"The general plan of the tests was much like that at Fredonia in most
of the vineyards, with the additions of plats for stable manure and
for leguminous and non-leguminous cover crops with and without lime.
From two to six check plats were left for comparison in each vineyard.
As already stated the results were often inconsistent in duplicate
plats in the same vineyard, and if one test appeared to point
definitely in a certain direction, the indication would be negatived
by results in other vineyards. In these experiments the yield of fruit
was the only index to the effect of treatments as it was not possible
to weigh leaves or pruned wood, or to count the canes left.
"Nitrogen and potassium in combination, which gave the largest gains
and greatest profit in the Station vineyard at Fredonia, showed a 13
per ct. increase in yield on one plat in the Jennings vineyard and a 9
per ct. decrease on the other; in the Miner vineyard this combination
apparently resulted in a 25 per ct. increase; in the Lee vineyard in a
2-1/2 per ct. loss; in the Hamilton vineyard a 17 per ct. gain; and in
the Grandin vineyard neither gain nor loss. In only two of the five
vineyards in which this combination was tested was the gain great
enough to pay the cost of the fertilizer applied. Similar
discrepancies, or absence of profitable gain, mark the use of the
other fertilizer combinations.
"Even stable manure, the standby of the farmer and fruit-grower, when
applied at the rate of five tons per acre each spring, and plowed in,
did not, on the average, pay for itself. Indeed, there were few
instances among the 60 comparisons possible, in which more than a
very moderate profit could be credited to manure. The average increase
in yield following the application of manure alone was less than a
quarter of a ton of grapes to the acre; while the use of lime with the
manure increased the gain to one-third of a ton per acre. The ton of
lime to the acre annually would not be paid for by the gain of 175
pounds of grapes. Cover-crops were used in five of the six cooeperative
experiments and proved even less adapted to increasing crop yields
than did the manure. There was no appreciable gain, on the average,
from the use of mammoth clover; indeed, a slight loss must be recorded
for the clover except upon the plats which were also limed, and even
with the lime the average yields on check plats and mammoth clover
plats differed by only one one-hundredth of a ton. Wheat or barley
with cow-horn turnips made a slightly better showing, as the plats on
which these crops were turned under, without lime, averaged about
one-twentieth of a ton to the acre better than the checks. With these
non-legumes, lime was apparently a detriment, as the plants with the
lime yielded a tenth of a ton less, on the average, than those without
it."
Practical lessons from the Fredonia experiment.
From this experiment it becomes clear that the use of fertilizers in a
vineyard is a local problem. General advice is of little value. It is
evident also that the fertilization of vineyards is so involved with
other factors that only carefully planned and long continued work will
give reliable information as to the needs of vines. Indeed, field
experiments even in carefully selected vineyards, as the cooeperative
experiments show, may be so contradictory and misleading as to be
worse than useless, if deductions are made from the results of a few
seasons. The experiment, however, has brought forth information about
fertilizing vineyards that ought to be most helpful to grape-growers.
Thus, the results suggest:
Only vineyards in good condition respond to fertilizers.
It is usually waste to make applications of fertilizers in poorly
drained vineyards, in such as suffer from winter cold or spring
frosts, where insect pests are epidemic and uncontrolled or where good
care is lacking. The experiments furnish several examples of
inertness, ineffectiveness or failure to produce profit when the
fertilizers were applied under any of the conditions named. They
emphasize the importance of paying attention to all of the factors on
which plant growth is dependent. Moisture, soil temperature, aeration,
the texture of the soil, freedom from pests, cold and frosts, as well
as the supply of food may limit the yield of grapes.
A vineyard soil may have a one-sided wear.
It is certain in some of the experiments and strongly indicated in
others that the soil is having a one-sided wear--that only one or a
very few of the elements of fertility are lacking. The element most
frequently lacking is nitrogen. Exception will probably be found in
very light sands or gravels which are often deficient in potash and
the phosphates; or on soils so shallow or of such mechanical texture
that the root range of the vine is limited; or in soils so wet or so
dry as to limit the root range or prevent biological activities. These
exceptions mean, as a rule, that the soils possessing the unfavorable
qualities are unfitted for grape-growing. The grape-grower should try
to discover which of the fertilizing elements his soil lacks and not
waste by using elements not needed.
Grape soils are often uneven.
The marked unevenness of the soil in the seven vineyards in which
these experiments were carried on, as indicated by the crops and the
effects of the fertilizers, furnishes food for thought to
grape-growers. Maximum profits cannot be approached in vineyards in
which the soil is as uneven as in these, which were in every case
selected because there was an appearance of uniformity. A problem
before grape-growers is to make uniform all conditions in their
vineyards, and the vines must be kept free from pests if fertilizers
are to be profitably used.
How a grape-grower may know when his vines need fertilizers.
A grape-grower may assume that his vines do not need fertilizers if
they are vigorous and making a fair annual growth. When the vineyard
is found to be failing in vigor, the first step to be taken is to make
sure that the drainage is good; the second step, to control insect and
fungous pests; the third, to give tillage and good care; and the
fourth step is to apply fertilizers if they be found necessary. Few
vineyards will be found to require a complete fertilizer. What the
special requirements of a vineyard are can be ascertained only by
experiment and are probably not ascertainable by analyses of the soil.
This experiment furnishes suggestions as to how the grape-grower may
test the value of fertilizers in his own vineyard.
Applying fertilizers.
When it is certain that vines need fertilization, and what is wanted
is known, the fertilizers should be put on in the spring and be worked
in by the spring cultivation. Stable manure should be plowed under.
Grape roots forage throughout the whole top layer of soil so that the
land should be covered with the fertilizer, whether chemical or
barnyard manure. Applications of commercial fertilizers are generally
spread broadcast, though it is better to drill them in if the foliage
is out on the vines and thus avoid possible injury to tender foliage.
Commercial fertilizers should be mixed thoroughly and in a finely
divided state. In leachy soils, nitrate of soda ought not to be
applied too early in the season, as it will quickly wash down out of
reach of the grape roots.
Over-rich soils.
Some soils are too rich for the grape. On these the growth is
over-luxuriant, the wood does not mature in the autumn, fruit-buds do
not form and the fruit is poor in quality. Certain varieties can stand
a richer soil than others. Over-richness is a trouble that may cure
itself as the vines come in full bearing and make greater demands on
the soil for food. It is well, however, on a soil that is suspected of
being too rich or so proved by the behavior of the vines, to provide
an extra wire on the trellis, to prune little and thus take care of
the rampant growth. Some soils, however, and this is often the case,
are so rich that the grape cannot be made to thrive in them; the vines
waste their substance in riotous living, producing luxuriant foliage
and lusty wood but little or no fruit.