March i, 1892.I 
THE TROPlCAt, AtjmCUl-TURlST, 
689 
entirely inadequate when the true value of potjash 
fertilization becomes better imderstood by the aigri- 
cultm-al community). Tlie potash salts, with the 
exception of kainit and sylvinit which are ci|ide 
minine products, are concentrated articles. 
The following presents a list of the various pot&sh 
salts and their average composition : 
Potash salts Contents in pounds per 100. 
containing Chlorine. Pure Pot- Magne^ Chlorine 
ash(Is.,o) sia (MgO) (t-i ) 
1 Kainit l^i^ ^'^''^ '^^'^ 
o;|yWi„iV.... KitoW 9-0 B4;4 
3. Muriate of Potash 53 to 58 O i 4b 0 
Potash Salts 
free from Chlorine. 
1 Sulphate of Potash 50 to 53 I'l 
2. Double Manure salt 27-2 15-8 
"Whenever a soil is deficient in potash, it is neces- 
sary to resort to artificial fertilization to supply this 
deliciency. Sand and peat soils are always wanting 
in potash, while heavy clay soils, as a rule, are less 
deficient therein. And yet, by contmous exhaustive 
cropping, even these soils deteriorate and artificial ap- 
plication of potash becomes necessary, as the follow- 
ing table illustrates, which represents the amount of 
potash annually removed by a crop of various plants : 
^ ■ Pounds of Potash. 
Corn 
Wheat . 
Barley . 
Rye ... 
Oats .. 
Peas . . 
.113 
. 39 
. 43 
. 50 
. 68 
. 50 
.154 
.137 
.103 
. 88 
Clover ■ ■ 
Potatoes 
Tobacco 
Grapes • 
These figures show to what extent even a rich soil 
gradually becomes deficient in this particular element, 
and how necessary it is to replace it, considering at 
the same time the requirements of the plant to be 
fed. Some plants with a strong appetite for potash 
have also the faculty of supplying their requirements 
in this direction from the soil, while others of a more 
dainty turn demand that their food be provided for 
them in an easily soluble form. To this latter class 
belong the cereals (wheat, rye, etc.) and also many 
fruit bearing plants, such as the vine, orange, peach, 
etc. Special attention should be given to the fact 
that, no matter how abundant the insoluble potash 
may be in the soil, soluble potash must be supplied 
in order to have the crop benefited by it. Consider- 
ation should likewise be given to the magnesia con- 
tained in some of the potash salts. Magnesia is a 
necessary element of plant food, and many soils are 
insufficiently supplied witli it, as Professor Grandeau 
has recently shown. 
The Magnesia salts are also the active agents of 
potash fertilizers when used as manure preservers. 
Tlie success of potash fertilization depends, of course 
largely upon the jn-oper application of the various 
potash salts and the following principles should be 
kept in mind : 
1. Posphoric acid, nitrogen and lime, are, as well 
as potash, essential to plant growth. 
A one-sided fertilization does not pay, except in 
very rare instances, and it is absolutely necessary to 
flupply all these elements essential to plant life. 
2. "Leguminous plants do not require nitrogenous 
fertilizers. 
Boans, peas, clover, vetches, and other plants be- 
longing to the class of loguminosEB, possess the pro- 
perty of absorbing largo <iuantitics of nitrogen from 
tho air, and therefore do not require nitrogenous 
manures. 
3. Green manuring saves Nitrogen and brings 
profit. 
Tho use of fertilizers frequently proves unprofitable 
through the great oxpenao incurred in buying costly 
nitrogenous maiuuos. This expense may be entirely 
avoided, if groi'ii manuring with leguminous plants 
is ju'aeticed. When peas, clover, etc., are liberally 
fertilized willi potash and pliospliorii- acid, tlu^y grow 
lusiu'iimtly, iwul when plowed uudcr, ihc huge amouul 
of nitrogen absorbed by them from the air suffices to 
insure a large succeeding crop. The abundance of 
organic matter, produced by gi-een manuring, more- 
over adds humus to the soil and improves its che- 
mical condition. Green manuring is consequently 
the best and cheapest method of restoring fertility to 
worn-out soils, and of making sandy soils productive. 
Green manuring by the use of leguminous plants 
(especially cow pea, vetch and crimson clover), in 
conjunction with potash-phosphate fertilization is 
sure to prove jjrofitable and hence is of great value 
to the Eastern and Southern farmers in particular. 
4. The use of lime should not be forgotten. 
Soils, especially sandy soils, which are deficient in 
lime, even when overlaying a calcareous soil, r quire 
that it be supplied to them, if one wishes to obtain 
the benefit of other fertilizers. 
5. Apply potash early and never use it as a top- 
di-essing. 
The potash salts are easily absorbed and held by 
the soil. If applied as top-dressing, they do not 
mingle with the soil, but remain near the surface 
beyond the reach of the roots. They should there- 
fore be plowed under to the depth, to which the 
plant-root will reach, and this should be done a con- 
siderable time prior to the planting of the crop. 
(5. Thorough cultivation is essential to success with 
fertilizers. 
A plant can only do its best, when the elements 
upon which it feeds, are presented to it under most 
favourable conditions. If by neglect of proper cultiva- 
tion, a soil becomes hard, it offers resistance to the 
growth of the roots, and can neither absorb nor retain 
the moisture necessary to plant growth ; under such 
conditions artificial fertilizers will prove of little 
benefit. To the objection, sometimes made, that 
artificial fertilizers stimulate the growth of weeds, it 
is only necessary to remark that the weed, as a 
robber, revels in a certain soil, and that what pro- 
motes the growth of the weed, renders the rightful 
owner of the soil also strong, and more profitable 
to the planter. 
7. Potash salts must be applied intelligently. 
An excess of chlorine in the soil injui-es the quality 
of certain crops, such as potatoes, tobacco, sugar- 
beets and oranges. Kainit, sylvinit, and muriate of 
potash, which are rich in chlorine, should therefore 
be avoided for such crops, and where a direct appli- 
cation is necessary, sulphate of potash and double 
manui-e salt should be used in preference. All ob- 
jectionable effects, however, can be avoided, and all 
b nefits retained, by applying potash ferti izers con- 
taining chlorine, a considerable time before the crops 
are planted, or better still, to the preceding crop. 
Either of these methods would prevent the injurious 
effect sometimes noted where tlie seed in planting 
comes in direct contact with crude fertilizers. 
Observations especially important in the use of 
potash salts : 
Cereals.— Potash-phosphate fertilization for cereals 
is particularly remunerative when practiced in combi- 
nation with green manuring through nitrogen-gath- 
ering leguminous plants. The nitrogen obtained by 
plowing under a heavy crop of cow peas, lupines or 
clover, suffices to produce a full crop of cereals if 
properly supplied with potash and phosphoric acid. 
An average quantity per acre is 200 to 458 pounds 
of kainit (or 50 to 120 pounds muriate of potasJi, and 
100 to 600 pounds of 12 per cent.- acid phospli'ate). 
A larger amount of potash, is better for barley! 
If nitrogen is not supplied by manuring, a nitro- 
genous fertilizer must be used ; 100 pounds of nitrate 
of soda per acre (or 2000 pounds cotton seed meal) 
is an average quantity. ' 
Meadows. — The effect of potash on meadows is 
vei7 marked, increasing not only the quantity of 
grass, but replacing the mosses and valueless herbs 
by nutritious grasses, (such a,s timothv Italian 
rye grass) and other very desirable leguminous 
plants, ihc latter cla.ss of plants, to which various 
clovers and vetches belong, produces a very nutri- 
tious hay, luid by their decaying roots, which con 
tain a good deal of nitrogen, they furnish this 
valuable sulistance to tlie nitrogen consuming "rasses 
11 is lo be observed thai the best results (Tuu be ob 
