Cultivation And Cover Cropping

In its broad sense cultivation is the treatment of the soil. Thus

understood orchard cultivation includes the sod mulch system as well

as the stirring of the soil with various implements. In its more

common and restricted meaning, however, cultivation is the stirring of

the soil about plants to encourage growth and productivity. To have

the apple tree in sod was once the commonly accepted method of orchard

treatment--a method of neglect and of "letting well enough alone."

With the advent of more scientific apple culture the stirring of the

soil has come to be the more popular method. But within the last few

years an improved modification of the old sod method, known as the sod

"mulch" system, has attracted much attention because of the success

with which a few men have practiced it. For a correct understanding of

these practices and of the relative desirability of these systems we

must again turn to underlying principles and purposes.



It may be said on first thought that tillage is a practice contrary to

nature. But it accomplishes what nature does in another way. Tillage

has been practiced on other crops than trees for so long that we think

of it almost as a custom. There are, however, scientific and practical

reasons for tillage.



THE EFFECTS OF TILLAGE on the soil are three fold, physical, chemical,

and increasing of water holding capacity. Tillage affects the soil

physically by fining and deepening it, thus increasing the feeding

area of roots, and by bringing about the more free admission of air

warms and dries the soil, thus reducing extremes of temperature and

moisture. Chemical activities are augmented by tillage in setting free

plant food, promoting nutrification, hastening the decomposition of

organic matter, and the extending of these agencies to greater depth.

Tillage conserves moisture by increasing the water holding capacity of

the soil and by checking evaporation.



Of all these things which tillage accomplishes in a soil, two should

be especially emphasized for the apple orchard, namely, soil moisture

and soil texture. That moisture is a very important consideration in

the apple orchard the effects of our frequent droughts are ample

evidence. The amount of rainfall in the Eastern States when it is

properly distributed is fully sufficient for the needs of an apple

tree. By enlarging the reservoir or water holding capacity of the soil

and by preventing the loss of water by evaporation, an excess of

rainfall in the spring may be held for later distribution and use.



As a rule, the improvement of a poor soil texture is as effective as

the supplying of plant food and much cheaper. The latter is of no

consequence unless the plant can use it. Scientists tell us that there

is an abundance of plant food in most soils. The problem is to make it

available. Plant food must be in solution and in the form of a film

moisture surrounding the smallest soil particles in order to be

available to the fine plant rootlets which seek it. Good tillage

supplies these conditions. Can they be obtained equally well in

another way?



It is claimed by the advocates of the sod mulch system of orchard

culture that it also supplies these conditions. Humus or decayed

vegetable matter holds moisture. Grass or other mulch decaying in the

soil increases its humus content and hence its water holding capacity.

By forming a mulch over the soil evaporation may be checked to some

extent, although probably not as effectively in a practical way, as by

cultivation. If there is a good grass sod in the orchard, moisture and

plant food made available by that moisture are utilized, and if the

grass is allowed to go back into the soil it continues to furnish

these elements to the tree. But there is a rapid evaporation of

moisture from the surface of the leaves of grass. In fact, grass may

well serve to remove an excess of moisture in wet seasons, or from wet

lands.



Laying aside theoretical considerations, let us see what practical

experience teaches on this subject. We have the accurate data on a

large number of western New York orchards showing the results of

cultivation and other methods of soil management. These data are

overwhelmingly in the favor of cultivation. In Wayne County the

average yield of orchards tilled for five years or more was 271

bushels per acre, as compared with 200 bushels per acre for those in

sod five years or more but otherwise well cared for,--an increase of

thirty-five per cent. in favor of good tillage. In Orleans County,

under the same conditions, the increase in yield due to cultivation

was forty-five per cent. and in Niagara County it was twenty-two per

cent. Records were made on hundreds of orchards and the results should

be given great weight in determining the system to be practiced, as

intelligent consideration of trustworthy records is to be encouraged.



These results were obtained in one region under its conditions and it

is quite possible, although not probable, that other conditions might

give different results. There are, however, special conditions as will

be pointed out later, under which the sod mulch method might be more

advisable than tillage. It is cheaper, makes a cleaner cover for the

drop fruit, avoids the damage from tillage implements to which tilled

trees are liable, and can be practiced on lands too steep to till. It

often happens, too, that it fits into the scheme of management on a

general farm better than the more intensive and specialized system of

cultivation. And it must be remembered that we are dealing with this

question from the point of view of the home farm rather than of the

commercial orchardist. So that where the sod mulch gives equally good

results it would be preferred under these conditions.