Sept. 1, 1898.j THE TROPICAL AGEICULTUPJST. 
197 
nant constituent in root, stem, brauch aud leaves 
and that Magnesia is distributed in considerable pro- 
portion through all parts with concentration in the 
seed. A soil, therefore, deficient in Potasb, Lime or 
Magcesia is lil;ely to proJuce sic'ily trees, end fuch 
a'e usuilly less able to res'st at'acks of pirasiiio 
blights, even if a sickly condit'on does not induce an 
atta"k. 
The Bota'-icil d pirtmeut of British Guiara in the 
"Proc edinss of th^ Agricultural Society"* make re- 
comniPtiditi-ns for the manur-ng of Cacao, baifd 
mTS esfecially on the noavoi'Jable losj of plant-food 
in (he b ans "and pulp of tlie Cicao. The crop of 
cu'e'l C'al barill'-) is taken at 250 lb. and rf Foras^ero 
at 150 lb. per acre ; whil? the Cacao grow i in Guade- 
loupe is assnrfd 'o give a retnrn of 450 lb. per acre, I 
quote as follows: — "The unavoidable loss in this 
Oolcnr, as compared wi'h ttat in Venezuela, gifen by 
Miircano, and with tbat in Guadeloupe, reported ly 
Boname, is as follows in lb. per acre per annum: — 
Demerara. Veoezuela. (Juadeloupe. 
Varieties cot 
Calabicillo. Furestero. stated. 
Nitrogen ... 11'30 7-26 8-7 7-3 
Phosphono 
Auhydride 5-32 4 19 4-5 2-8 
Pctash . . 6-31 3-20 37 4 3 
Lime ... -65 -47 1-4 4 
Magnes-a ... 269 1-95 _ 10 1-4 
" Theie is a general ronci rdance in theie re^n't?, 
fhowing the low amoun's of fonttitijer.ls necessarily re- 
bdov d from the soil by the produolion of a crcp of CacDO. 
"In the al sence of direct e."tperimen' s cn the 
manuring of Cac40, we hive formfd cur opinion that, 
wlren Erythrii ae are used as fbade frees, mfnur- 
ing sho> Id be dirccied 'a'ge'y towari's the upkeep of 
the pota-h fnd vhosphates nec fsa-y t) eiable the 
si ade trees to do their part as Nitrogen collectors ; 
and that, when no sla'e trees are us d, the mine al 
manuring oapht to be more large'y snppleniented 
by Nitrrg n. Thu-', the following mixiure cr mixiurfs 
of other matt rial, y'eli^ing the sfme propoiticnj of 
Nitrogi n, Potash, and Phosphates per acre, might be 
advise ily tried in Cacao plantations. 
Erythrinae used 
for shade. Not shaded. 
Nitrate of So -! a 1 cwt. 2 owt. 
Superphrspbate of lime 
36 per cent Soluble 3 ,, j ,, 
Potash Snlpba'e 1 ,, in 
" The materials should be we 1 mixed and appliei in 
quantity, accordi s: to the number of trees planted 
pt-r acre arouncT each trae, at a ''i'-taiice of about twj 
to three feet from the stem." Whether the foregoing 
are intended as annual or biennial application is not 
stated. 
In ttie above recipe, if Nitrate of Potash, which 
would supply both the Nitr' gen and the Potash, were 
substituted for Nitrate cf Soda and Sulphate of Po'ash, 
the equivalent would ba approximately: — 
Sha' ed. Not sha-led. 
Nitrate of Potash ... 140 1b. 2801b. 
Superpho'pl ate of L'me 36 
per cent soluble ... 84 56 
In the ca e of Phoephrric acil supplied in lesg solu- 
ble forms than Superphosptate, the quantity would 
have to be much greater, I s'lould say not leas than, 
double. While tli ' unavoidable h ss of Nitrogen, Po- 
tash, and Phosphates in the b ans snd pulp is pnoall, 
yet, when the amoun's of thefcconslitueois which are 
requ"r d for Uie annual incren^ent to (he tree are alio 
regarded an so much plsn'-foid removed from the 
soil, it puts a different complexion on the mat er. 
If a oalc'ilation of th" manures required for ca- 
cao cultivation b« b ped cn t-iHe G, and the asbea 
only of the pod-h' sks be fupposed tj be returufd to 
the foil, the f.-Uowinc data may bo taken as a 
guir'e in preparing suitable mixaires. For one manu- 
' For a ^e•usal of this I am iiideb'.ed to Iklr. Jehu 
Fergasou of the Cci lon Ohsn-vei; 
ring, ihi effects of which las'; for two yia.V3, the 
whole of the Nitrogen in c:ilumn 3 may b a returned 
to the soil, siy about 37 lbs. This would be a sist- 
iag nat ire to thj es ent of one half of the Xl rogoa 
required for two years : and, if ihe Cacio is crown 
under good shade irj' s. which act as Nitrogen collect- 
ors, th^ amount of Nitrogen may be greatly ri>duced. 
The qu n'ity of Polash wouH be deduced from 
column N-<. 2 cf tabl^ G, and, say 60 lb, might be 
al'owed, thus a^sistmg nature, in fhis ca-e, also, to the 
extent of one half of tbe rpquireraenis for twJ ye^irs. 
In the ciseof Pho>pho:ic ucid, the tabular number 
is 11-71, ssy 12 lb. When a seed crop is to te ta'sed, 
it is advisable to bs libiral with the Pbosphor'c acid, 
so to enrich the soil with it. If adJid in 
the soluble s'ate, not less than 30 lb. equsl 
to 181 lb. Superphosph'it?, would probably be a 
sufRcient qumtity; a-d us'nj less s^lubla m-vterlals, 
such ts thoraas Phosphate powder or bone meal, 60 to 
76 lb ■. would not be too much- 
The folloffirg wo'old bo an example of a manure" 
mixtur', using soluble m. terials: — 
Per acre. 
Superphosphate of Lime 36 % solubla ... 182 lbs. 
Sulphate of Pofca.«h 60 % Potash ...120 „ 
Nitrate of S^da ... ... ...237 ,, 
or (Sulphate of Ammon'a. ,.. ... 18G ,, 
With^ goo I shade trees to act as Ni'r^gen-collectors, 
the Nitrogenous manure might be reduced by as much 
as a half, and this i'em, whether as Nitrate of Soda 
or Sulphate of Ammonia, being in sucli a very soluble 
form, might, with advantage, ia any case, be halved 
and iipp'ied annually instead of bienr:jally, or the whole 
receipt might be halved aid applied annually. 
Th-i followiag wf uUl be a few typical examples of 
mixtures in wh'cli the Phosphates are ia less soluble 
forms than Superphosphate : — Per acre. 
Bone meal ... ... 300 lbs. 
Sulphafe of Potash ... ... 120 „ 
Castor Cake ... ... 4C0 ,, 
With g;od shode trees the Castor Cake might be re- 
duced to 100 lbs. Per aore. 
Thomas Phosphate Powder 
Sulphsts of Potash 
Castor Cake 
360 lbs. 
120 „ 
570 „ 
With good s'lade trees the last item mi ^ht ba reduced 
a,i low a? 285 lbs. Per acre. 
Thomas Phcsphata Powder ... 360 lbs; 
Sulphite of Potash ... ... 120 „ 
Blood meal ... ... ... 300 ,, 
With good shade of trees the last item might be re 
duced as low as 150 lbs. 
Fish Manure ... ... ... 500 Iba. 
Bone meal ... ... ... 200 „ 
Sulphate of potash ... ... 120 ,. 
W'ith good 'hade trees the fish manure might be reduced 
as low as 200 lbs., adding 50 lbs. to the bone meal. 
The foregoing will suffice as essimples repectively of 
the more soluble and of the moi'e slowly available 
manures ; while the following might be taken as an ex- 
ample of a judicious mixture of the above per biennial 
application : — Per acre, 
Ni'rate of Soda ... ... 119 lb. 
or (Sulphate cf Ammon'a ... 93 lb) 
Blood meal ... ... .. 100 lb 
or (Castor Cake ... ... 200 1b) 
Superphosphate of Lime 3G % soluble 
Phosphate ... ... ... 911b. 
Bone meal ... ... ... IbO tb 
Sulphate of Potash ... ... 120 1b 
It \\-ill be observed that, in the manure mixtures, no 
special aironut has been lakeu of Magnesia. In all the 
common Phosphatic manures, Lime is siipolied in con- 
gidembly larger proportion thah the Phosphoric a?id ; 
but, in most manure* olher t'laa the cruder Stassfart 
salts, iMagnesia is present in very small proportion. Ia 
Thomss' Phosphate powder, however, 5or G per cent may 
bo looked for, which in 360 lb. represents half of the 
Magaesia required by the Caoao tree for two years. lo 
