244 
be followed by thoroughly working down 
the surface with disc or similar tool to 
chop up the crop and pack the soil down 
to preserve the moisture. Continue the 
surface tillage from now on until August, 
and seed again to cover crop if necessary. 
The depth at which the surface work- 
ing tool should run has been carefully 
tested out both in the laboratory and in 
the orchard. As a result of these tests 
we find that from three and a half to 
four inches of dust mulch is as effective 
to conserve moisture as 10 or 12 inches. 
W. S. THORNBER 
From a Connecticut View Point 
Where Rainfall Is Light—Under the 
system of clean culture, cultivation com- 
mences as soon as the soil may be worked 
in the spring and continues till about 
the middle of August. It is recommended 
especially for sections where the rainfall 
is light during the growing season. By 
maintaining a loose dust mulch on the 
surface the system is very effective in 
conserving moisture. On the other hand 
the continuous cultivation tends to de- 
plete the supply of plant food and humus, 
or decaying vegetable matter. To main- 
tain the fertility of the soil under this 
system requires liberal applications of 
stable manure or some substitute. This 
system, as practiced by some growers, is 
very similar to tillage with cover crops, 
and gives fairly good results. These 
growers cease cultivating about the mid- 
dle of July or the first of August and 
allow the weeds to grow up and cover 
the ground. The weeds here assume the 
function of a cover crop. Clean culture 
alone not recommended. The clean cul- 
ture system, pure and simple, is not 
recommended for Connecticut. 
Time—The early spring plowing should 
be followed by repeated cultivations. The 
aim should be to keep a deep, loose soil- 
mulch on the surface. The most success- 
ful apple growers harrow their orchards 
every eight or ten days during this period, 
and oftener, if rains occur in the interim. 
This treatment liberates plant food, saves 
moisture, and keeps the weeds down. Any 
tool that will Keep the surface loose is 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
suitable for this purpose. About July 
15th cultivation should cease and the 
ground be sown to some good cover crop, 
to be plowed under in the following 
spring. 
A good cover crop should make suff- 
cient growth to protect the ground during 
the winter and spring and to supply 
abundant vegetable matter, which, when 
turned under, will improve the physical] 
condition of the soil and will contribute 
plant food. The clovers and winter 
vetches are very Suitable for this pur. 
pose. These crops are nitrogen gatherers 
and if a large growth is produced and 
turned under each year, there should be 
mo need for the application of nitrogenous 
fertilizers. On the contrary, by repeated 
cover cropping it is possible, especially in 
later years, to produce too much wood 
growth. In which case, instead of plow- 
ing under the cover crop, it may be 
mowed and left on the ground. The ob- 
ject should be to produce a normal and 
uninterrupted annual growth. Trees that 
grow too fast are more likely to be in- 
jured by severe winters, to have a weak 
root system, and to form a structure that 
is not sufficiently strong to bear the 
weight of large crops of fruit. Most fruit 
growers, however, are more likely to err 
in the other direction and allow their 
trees to become stunted, from which con- 
dition they may never recover. 
Grass Mulch on Hillsides 
On rugged hillsides where there would 
be danger of washing, the necessity for 
retaining a sod cover is undisputed. In 
view of the difficulty of conducting the 
spraying and harvesting operations on 
steep hillsides, it is very doubtful whether 
such land should ever be chosen for or- 
chard purposes. It is probable that a com- 
bination of the mulch and tillage sys- 
tems will be found most useful for New 
England conditions. The important 
thing to remember at this time is that, 
regardless of what system the grower in- 
tends to follow, the preparation of the 
land is essentially the same. On steep 
hillsides, however, where cultivation is 
not feasible, the trees may be set in the 
sod and small circles cultivated around 
