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


"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


"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.



Plat. 5-year

No. 1909 1910 1911 1912 1913 avg.



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




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:



(Averages for three years.)





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


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.