Vol. LXIX. No. 4053 NEW YORK, JULY 2, 1910. weekly, $ 1.00 per year 
THE PRINCIPLES AND PRACTICE OF EARTH 
MULCHES. 
Loss or Gain from Cultivation. 
In a very dry time jnst how does the repeated shallow 
cultivation of the surface help a crop? In other words, 
when you have a dust mulch, why continue cultivation? 
Why not break the crust as soon as practicable after a 
rain, then stir the ground again after the next rain? 
Why cultivate dust? What action takes place when you 
do ? E. D. 
The very best farmers in all parts of the world, and 
in all times, have ever been and are keen to under¬ 
stand the principles of their practice. So, too, have 
they been close observers and capable of recogniz¬ 
ing and of holding fast to that which is good. 
Being essentially men of action rather than of words 
they hesitate to express in writing even their most 
positive knowledge and strongest conviction. E. D. 
is one of these, and the more I study the old prac¬ 
tices in soil and crop management the more clearly 
I come to realize that 
the good farmers of all 
nations have usually 
grasped the principles of 
practice with sufficient 
clearness to lead to 
good, if not to the best, 
results. And so, in parts 
of China, the past Sum¬ 
mer we saw the appli¬ 
cation of the dust blan¬ 
ket in conserving soil 
moisture for crop needs 
carried to an extent to 
which we have never 
dreamed. Throughout 
China, Korea and Japan, 
wherever we went, be¬ 
tween Canton in the 
south and Mukden in 
Manchuria, and between 
there through Korea and 
Japan, almost every crop, 
wheat, barley, millet and 
even rice is intertilled or 
hoed. Wheat, barley and 
often millet as well as 
rice are planted in hills 
as well as in rows so 
that hand or horse hoe¬ 
ing may be practiced. 
The illustration Fig 291 
(page 691) shows a far¬ 
mer developing an earth 
mulch in his field of Kaolian or large millet, between 
Tientsin and Peking, after middle June. It had 
rained during the night, closing a severe drought 
which had lasted since early Spring. As we trav¬ 
elled on the train between 6 and 8.55 A. M. between 
Tientsin and Langfang we could have counted hun¬ 
dreds of these farmers working in their fields to de¬ 
velop a mulch at the earliest moment The sky had 
cleared and the wind was strong, as the illustration 
shows, and not a minute was to be lost in developing 
the needed earth mulch. The hoe being used is a 
heavy tool with a blade 13 inches long and nine 
inches deep, and is hung at such an angle with the 
handle that it is only with difficulty that it may be 
drawn other than parallel with the surface, and hence 
so as to develop more than a shallow mulch. In 
using the hoe the man throws it as far forward as 
his arms, body and its long handle will reach, then 
drawing it to him in a single sweep, the hang of the 
hoe and its weight causing it to cut under the sur¬ 
face to a depth of 1.5 to two inches. Two such 
strokes of the hoe cover the space between the rows 
and the man goes forward at a good speed. The 
blade is detachable from the heavy iron shank and so 
is the handle, and from the standpoint of the present 
Chinese conditions, where we found on the farms as 
many as six, eight, 10 and even 12 people to 1.5 to 
2.5 acres of land, this is an extremely efficient mulch- 
producing tool, and one reduced to the lowest terms. 
HOW MUCH WATER MAY EARTH MULCHES 
SAVE?—In a series of trials with different soils 
exact comparative results were obtained, showing 
that, in the case of a black marsh soil, the loss of 
water from the firmed soil surface was at the rate 
of 4,660 pounds per acre and per day greater than 
from the same soil under a one-inch mulch; that it 
was 6,360 pounds greater than from a two-inch 
mulch; 6,632 pounds greater than from a three-inch 
mulch and 6,710 pounds greater than it was from a 
four-inch mulch, per day and per acre. From a sandy 
loam the losses per day and per acre from the firmed 
soil surface were greater than from the one, two, three 
and four-inch mulches by as much as 7,356, 8,044, 
9,080 and 8,522 pounds; while from a virgin clay 
loam the losses from the firmed surface exceeded 
those from the one, two, three and four-inch mulches 
as much as 23,080, 28,686, 30,496 and 30,602 pounds 
per acre and per day. Under the conditions of these 
trials the firmed soil surface lost water by evapora¬ 
tion at the rate of 11,760 pounds from the black 
marsh soil; 14,830 pounds from the sandy loam and 
48,280 pounds from the clay loam per day. These are 
equal to rainfalls of .052, .065, .013 inches of water 
on the level lost daily by surface evaporation from 
the respective firmed soils. 
HOW MUCH CORN LOSSES AND SAVINGS 
REPRESENT.—A long series of careful experiments, 
with corn and other crops, have shown that from the 
time of planting to maturity water is lost by evap¬ 
oration from the soil, under the conditions of the 
best earth mulch, and through the leaves and stem 
of the plant, at the mean rate of about 270.9 pounds 
of water for each pound of dry substance produced 
above ground in the case of the corn plant. On this 
basis the mean saving of the one-inch mulch, for the 
three soils, is at the rate of 43 pounds of dry sub¬ 
stance in corn and stalk per day and per acre; with 
the two-inch mulch 53 pounds, and with the three- 
inch mulch 57 pounds per day and per acre. It must 
not be understood that these values may be applied 
to average field conditions with sufficient definiteness 
so as to serve as a basis for calculating the increase 
of crop due to good cultivation, or for calculating 
whether the cost of cultivation exceeds the cost of the 
increase of the .crop resulting from the cultivation. 
SAVING FROM FREQUENT CULTIVATION. 
—Critical experiments have shown that when the same 
soil was left with its surface not cultivated it lost 
water by evaporation at the rate of 14,482 pounds, per 
acre and per day, but when cultivated one inch deep 
once in two weeks the loss was 3,458 pounds less; 
when cultivated once per week and one inch deep the 
loss was 3,582 pounds less, and when cultivated twice 
per week the same depth of mulch gave a loss of 
3,426 pounds per day and 
per acre less than from 
the firm soil. When the 
cultivation was two 
inches deep the cultiva¬ 
tion once in two weeks 
saved 2,298 pounds; the 
cultivation once per 
week saved 3,440 pounds 
and the cultivation twice 
per week saved 4,174 
pounds of water per day 
and per acre. And when 
the cultivation was three 
inches deep the moisture 
saved with the cultiva¬ 
tion once in two weeks 
was at the rate of 2,242 
pounds; the cultivation 
once per week saved 
3,852 pounds and the cul¬ 
tivation twice per week 
saved 4,582 pounds per 
day and per acre. 
The length of the in¬ 
terval between cultiva¬ 
tions in these cases is 
four times as great in 
the first as in the third, 
and twice as great in the 
first as in the second. 
Let us set the results 
where the eye can see 
them together. 
From this table it is clear that the cultivation of 
greatest frequency has saved the most water and 
Cultivated — • 1 2 4 
1 inch deep .3,454 3,582 3,920 
2 inches deep .2,298 3,440 4,147 
3 inches deep .2,242 3,852 4,582 
the cultivation of least .frequency has saved the least 
moisture. Look now at the column 1 in the table, 
where the cultivation was once in two weeks. Here 
the greatest loss was when the cultivation was three 
inches deep. This brings out most clearly one of 
the principles underlying frequency of cultivation. 
Where the deep mulch lies for two weeks in contact 
with the damp undisturbed soil it gradually becomes 
moist and compacted by the capillary rise of inois;- 
ture into it, and this compacting and the wetting in¬ 
crease the rate at which the moisture is drawn up 
from below, so that when cultivation is repeated at 
the end of two weeks there is a large volume of 
wet soil to be brought to the surface, which mechan¬ 
ically increases the loss from the field. But when 
the cultivation is more frequent the entire mulch is 
kjpt drier and the rise of water into it is corre- 
HARLEY SHERMAN, “THE MAN WHO DRIVES THE STEERS.’’ Fig. 289. 
