October 27, 1881. ] JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 371 
an injurious extent. That in many instances this is so could 
very easily be proved. In the case of manure from cow houses 
matters are much worse, as, for a reason to be presently 
explained, cow manure is originally deficient in potash. We 
wish particularly to dwell on this, for our aim is to draw 
special attention to the source of potash, and the necessity of 
furnishing an abundant supply in order to secure the greatest 
economy, and economy, always a virtue, has become in many 
instances a pressing necessity in many gardens. 
Those who read this and who may believe that there is “ some¬ 
thing in it,” may wish to experiment in order to prove the 
truth or otherwise of our assertions. We wish nothing better, 
and hope the data here furnished may be heeded, so that any 
experimenting which may be done may be really calculated 
to produce the right effects. 
We have shown that potash is largely demanded by Potatoes, 
and also hinted our belief that most garden soils are deficient 
in it. We know of no plant that will more readily show 
whether this is the case or not than the one named. We have 
carefully experimented with artificial and natural manures 
rich in potash salts, and this on maiden soil and in rich old 
garden soils, with surprising results. Before giving some of 
these we beg to submit the following well-known facts— 
1, Potatoes on old rich garden soil produce much greater crops of 
haulm than of tubers ; indeed, great crops of these are not the 
rule in such soils, and heavy supplies of manure increase the 
evil. To prove this we intended quoting from different autho¬ 
rities, including the Journal ; but the writers of almost every 
article on Potato-growing so agree with other writers on 
this that we content ourselves with merely restating a well- 
known fact, and such as every gardener of any experience is 
acquainted with. Surprise and astonishment is often expressed 
at this fact, but it is one which the student of agricultural 
chemistry -would expect, and amply verifies what has been 
often called mere theory. Considering that garden crops tend, 
under ordinary manuring, to exhaust the soil of what is neces¬ 
sary for the formation of Potato tubers, and tend to an accu¬ 
mulation of what ought to produce a grand crop of haulm, no 
surprise need be felt when big shaws and small Potatoes are 
produced on “ rich ” garden soil. Rather should the occurrence 
be taken as proving the accuracy of what the chemists have 
taught. 
No artificial and no natural manure surpasses urine, and 
especially cow urine, for supplying potash to plants. One 
would, therefore, suppose that a dressing of urine to soil in¬ 
tended for Potatoes would in all cases prove beneficial. But 
such is not the case. This seems paradoxical, but a little 
thought shows that it is not. Urine is also rich in compounds 
of nitrogen, which excite rank growth. Therefore, although 
much potash is applied with the urine, the nitrogen supplied 
with it causes a growth so strong that, small as is the amount 
of potash needed by the haulm, the extra growth it makes 
takes much of the potash, and little is left to be available 
for the formation of tubers. At least, this is how we explain 
the action of urine when applied to Potatoes on rich garden 
soil. Whether the explanation be correct or not the fact 
remains, and with facts we deal. 
This experiment we have made repeatedly, and for comparison 
we have also made another under exactly the same conditions. 
Wood ashes, as is well known, contain much potash in a form 
very easily appropriated by plants. On rich soils we have 
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WHAT PLANTS USE. 
(Continued from page 249.) 
SOURCES OF PLANT FOOD—POTASH. 
have seen that potash is a principal ingredient 
in the ash of plants, and especially so in the 
case of those cultivated for food. It may 
be laid down, indeed, as a general rule, that 
any ordinary rotation of garden crops will 
remove more potash from the soil than any 
other mineral compound. If the plant food 
which is being continually added contain potash in 
sufficient quantities the fertility of the soil, so far as 
that depends on the presence of potash, will not 
diminish. At the same time it is possible to cram soil full of 
manure and yet the soil prove less productive than it ought to 
be. Our conviction is, that this is the state of matters in nine- 
tenths of our gardens. Over-manuring is a decided evil, yet 
we are safe in saying that many over-manured gardens are 
infertile more for want of potash than because of an excess 
of other substances. No matter how abundantly lime or soda 
may be present, if potash be deficient the plants will only grow 
to the extent of the potash they find. Hence plants may 
starve—do starve—on a soil that for other plants may be 
extremely rich. When we examine what is given as plant 
food in a majority of instances we can easily see that such 
must be the case. Ordinary farmyard manure—that made of 
about the usual number of ail the different animals usually 
found on farms—contains the substances we have named in 
proportions approaching the following figures. We ought to 
state here that analysis of farmyard manures can only be 
approximate, as the kinds of animals kept, the state of the 
drainage, and the food used, all tend to make differences in 
this respect. Farmyard manure contains of water, 72-48 ; 
organic matter, 13 94 ; potash, 0-32 ; soda, 016 ; lime, 0-59 ; 
magnesia, 0 02 ; phosphoric acid, 0'31 ; sulphuric acid, 0J2 ; 
carbonic acid, 052 ; ferric oxide and alumina 0-45 ; sand, 
1109 ; total, 100 00. 
A reference to the above results will show that ground con¬ 
tinually enriched with such manure, and cropped with a 
rotation of garden crops requiring more potash than lime or 
phosphoric acid, may present these last two in due or over¬ 
abundance, and yet fail in presenting enough of potash ; or if 
such manure be applied in quantities sufficient to furnish 
enough potash, then many other valuable matters are partly 
lost, or may in time, under certain circumstances (such as we 
mentioned in a former paper when urging the necessity of 
washing Vine and other borders under glass), accumulate to 
No. 70.—Yol. III., Third Series. 
No. 1726— Yol. LXVI., Old Series. 
