1912. 
THfcC RURAL NEW-YORKER 
THE USE OF HAIRY VETCH. 
Having had but very little experience with Hairy vetch, 
and desiring to use it under conditions dissimilar to those 
presented in your paper from time to time as I have read 
them 1 make the following inquiries : 1. What can be ex¬ 
pected in the way of a catch when Hairy vetch is sown 
with buckwheat, buckwheat being commonly considered as 
a crop well intended to kill out all other growth, and is 
often grown for that .particular purpose? 2. When a seed 
erop is desired, for purposes other than harvesting, should 
Hairy vetch be sown in the Spring to mature seed that 
same season or in the late Summer to mature seed the 
following season? In what month in either case should it 
be expected to produce ripened seed in central New York? 
3. If a seed crop is left until over-ripe or even not cut at 
all, will it reseed itself sufficiently well to produce a 
growth the following season about equal to that of the 
first season? 4. Would a crop of ripe seed have sufficient 
feeding value to make it worth while to pasture hogs or 
fowls upon it? The above questions arise in considering 
the use of Hairy vetch in a large orchard where fowls are 
kept on the colony plan and range over the whole area, 
and where the season's growth is wanted in the Autumn 
to mulch the trees. a. h. 
New York. 
1. I have had no experience in sowing Hairy vetch 
with buckwheat, and consequently am not able to 
advise definitely for or against the sowing of Hairy 
vetch as a catch crop with buckwheat. I am of the 
opinion, however, that this practice might prove to 
be unsatisfactory, for the reason that on account of 
the habit of growth of the buckwheat crop it seems 
probable that the vetch crop would be seriously re¬ 
tarded in growth under such conditions. I have seen 
buckwheat crops sown upon orchard land which 
had previously grown a crop of vetch, the vetch being 
plowed under in May, buckwheat sown in June, and 
plowed under in August and September. This prac¬ 
tice is being followed in certain Citrus groves in 
California, where it is desirable to secure a large 
amount of green crop material for plowing under in 
order to improve the soil tilth of these orchards. I 
do not believb there is any data which will show'defi¬ 
nitely the results of this practice in fruit production. 
2. My experience has been that the best results in 
Hairy vetch seed production have been secured by 
sowing vetch seed in the Fall, or with some nurse 
crop, such as rye or barley. Our best results have 
been secured by sowing the vetch seed from August 
IS to September 15. Under such conditions the vetch 
seed has ripened and is ready for harvest by the last 
week in June the following season. While these dates 
have been determined under Connecticut conditions, 
I suspect that about the same dates will apply to the 
conditions in central New York. 
3. Where we have left Hairy vetch crops to mature 
seed we have found that the following season there 
has been a self-sowing sufficient to produce a satisfac¬ 
tory growth the following season. Where the vetch 
fields have been near poultry yards such has not al¬ 
ways been the case, on account of the fact that fowls 
search for the vetch seeds so persistently that the 
seeding is largely reduced by this means, so that a 
light or unsatisfactory crop is obtained by this method 
of seeding. I have observed self-sown vetch crops 
in several orchards this 
season in Connecticut 
and Massachusetts, and 
have found that satisfac¬ 
tory cover crops have 
been secured in this 
way. 
4. The desirability of 
pasturing hogs or fowls 
upon vetch crops will 
probably depend upon 
the character of the crop 
produced. We have 
found that hogs and 
fowls feed upon this 
crop with the best re¬ 
sults ; in fact, as sug¬ 
gested above, it is diffi¬ 
cult to mature seed 
crops where the fields 
of vetch are open to the visits of animals or poultry, 
on account of the fact that they keep the plants 
cropped down so closely that it is impossible for them 
to mature seed, and if seed is matured and the poul¬ 
try is turned into such fields they search so persistently 
for the seed that most of it is eaten and little allowed 
to remain for growth the next season. I would sug¬ 
gest an experiment with a part of this orchard 
in using Hairy vetch for cover crop or seed purposes 
and for a pasture for the animals and poultry. If 
possible I would suggest that a part of the sowing 
be with some nurse crop, such as rye or barley, pref¬ 
erably rye, as barley may not live through the Winter 
under the inquirer’s conditions of soil and climate. 
If, as suggested in the last part of the inquiry, a 
mulch is desired for the trees in the Autumn, it will 
probably be desirable to sow the crop early, say in 
July, or at least the early part of August. Under 
these conditions I have seen large crops of vetch 
grown, the vines of which died down in part during 
the Fall aiid Winter and produced a heavy mulch on 
the surface of the ground which can be plowed under 
the next season if desired. In securing Hairy vetch 
seed I think it would be advisable to investigate very 
carefully the character of the seed, and would suggest 
that samples be sent to the State Experiment Station 
or to the U. S. Department of Agriculture for identi¬ 
fication. Some growers have found that Hairy vetch 
seed that has been purchased has been mixed with 
Spring vetch seed, in some cases the Spring vetch 
seed constituting the larger proportion of the bulk of 
the seed purchased. As the Spring vetch seed is not 
hardy under Eastern conditions, this adulteration has 
JOHN M. CONKLIN, AN OLD R.N.-Y. FRIEND. 
been the cause of some disappointment in sowing this 
crop. The tremendous increase in the use of imported 
vetch seed and its consequent rise in price has given 
rise to favorable conditions for the adulteration of the 
seed of this variety with the seed of cheaper vetch 
varieties, and consequently it is necessary to exercise 
all possible precaution in the purchase of Hairy vetch 
seed if it is desired to secure such seed free from 
mixture with other ve* h seed which is not readily 
identifiable except by tests, or expert knowledge. 
A. D. SHAM EL. 
CARBON DIOXIDE IN GREENHOUSES. 
A recent writer in the Gardener's Chronicle, an English 
paper, takes the position that an excess of carbon dioxide 
is a. desirable thing for plants, particularly those in a 
greenhouse. He describes some experiments of driving the 
air from a cow stable into and through a greenhouse, on 
the theory that this will add more of the dioxide, and 
benefit the plants. He thinks also that possibly smoko 
driven into such a greenhouse would help. Is it possible 
that this artificial supply of carbon dioxide would have 
any useful effect upon plants? 
Physiologists agree that all green-leaved plants ob¬ 
tain their carbon solely through its absorption, during 
sunlight in the form of carbonic acid gas, more cor¬ 
rectly known as carbon dioxide, by the chlorophyll or 
green coloring matter contained within the leaf cells 
and possibly the bark of the younger twigs. This 
carbon is converted by the chlorophyll into starch 
and subsequently into the woody fiber, sugar, gum, 
tannin, oil and other constituents, reappearing as 
charcoal when the plant tissues are imperfectly burned. 
The leaves obtain carbon dioxide by a process of 
respiration through their stomata or pores, much as 
animals obtain oxygen, but the process is inconceiva¬ 
©i 
bly slower and almost, altogether ceases in the ab¬ 
sence of sunlight or bright artificial light. Lichens, 
fungi and other of the lower forms of plant life 
appear to obtain carbon by absorption without the 
aid of chlorophyll, but the higher plants all use their 
leaf structures for this purpose. 
It is often contended that if plants were afforded 
more abundant carbon dioxide than is normally con¬ 
tained in the air they would grow more vigorously, 
and the experiments of Kreusler, a German scientist, 
appear to bear out the assertion. Pie found that tak¬ 
ing the growth of the hornbeam, nasturtium and 
raspberry in normal air containing three one-hun¬ 
dredths of one per cent of carbon dioxide, as 100; 
six one-hundredths gave an assimilation of 127, or 
one-fourth more. Eleven hundredths, or 3j4 times 
the normal, gave an assimilation of 185, while 7jJ 
per cent of carbon dioxide—quite 220 times as much 
as is commonly found in air—gave an increased as¬ 
similation of 230. After that the ratio fell until only 
an assimilation of 2£6 resulted from increasing the 
carbon dioxide to 14 l / 2 per cent, or 440 times as much 
as air naturally contains. These experiments, under 
highly artificial conditions, did not apparently result in 
any very noticeable useful developments of the plants 
in question. That the assimilation of carbon in the 
form of its dioxide was formerly far more extensive 
than in the present era is borne out by the great de¬ 
posits of coal resulting from the transformation of 
the luxuriant forests of the carboniferous period of 
geology. It is supposed that the atmosphere of that 
era was far more highly charged with carbonic and 
aqueous vapors, which together with the high tem¬ 
peratures indicated, resulted in an astonishing vege¬ 
table growth. 
As to the benefits to be derived from drawing the 
air from a cow stable through a greenhouse, the 
writer can offer no opinion, as he has not read the 
article in question. If there were cattle enough there 
would certainly be an appreciable increase in the car¬ 
bon dioxide that reached the plants, as this substance 
is exhaled as waste matter in the breath of the cows. 
There would also likely be perceptible ammoniacal 
fumes from other waste products, that could be ab¬ 
sorbed by the moist soil in which the plants grow and 
be finally taken up by the root hairs as nitrates in so¬ 
lution—thus directly nourishing the plants. Whether 
the net gain of this method of utilizing the cow’s 
breath is worth the trouble is a matter for further 
demonstration. The idea of forced ventilation of 
plant greenhouses is an old one, some of the earlier 
constructions being provided with a bellows taking in 
the outside air and driving it through the interior, 
but modern practice finds such appliances needless. 
That plants are really stimulated by increasing the 
proportion Of carbon dioxide, just as animals are by 
raising the normal per cent of oxygen, especially in its 
nascent, active form known as ozone, appears to be 
borne out by Kreusler's experiments, but its practical 
application would meet with many difficulties. Car¬ 
bon dioxide is very heavy gas seeking the lowest levels 
like water, and in pro¬ 
portions greater than 
one-half of one per 
cent in the inhaled air 
is distinctly injurious to 
animal life. It is also 
to be remembered that 
plants can only assimi¬ 
late carbon in light and 
that if it were proposed 
artificially to increase 
the natural proportion 
of carbon dioxide in a 
greenhouse; besides the 
other complications, 
some provision for re¬ 
frigeration would be 
needed to prevent undue 
heat, as it would only be 
effective in sunlight 
when it is usually necessary to open the ventilators 
to moderate solar heat. 
As to driving smoke through a greenhouse, the 
prospect is even less promising; The products of com¬ 
bustion, other than carbon dioxide and watery vapor, 
are generally injurious to vegetatiop. Plants do not 
thrive especially well near large cities, where the 
enormous consumption of fuel actually increases the 
carbon dioxide content of the air. On the other hand, 
many species languish from the irritating effects of 
the sulphur compounds, volatile hydrocarbons and 
other combustion products, and also suffer from the 
deprivation of light caused by the deposition of soot 
on the foliage; nor do they thrive in conservatories 
heated by the direct flame of gas or oil stoves. 
Plant physiology is a little developed science, and 
no individual may safely predict the possibilities of 
even the immediate future, but applications of soda 
water gas and inhalations of smoke certainly do not 
hold great promise for modern horticulturists. v. 
DINNER TIME FOR THE FEATHERED FARM WORKERS. Fig. 30. 
