186 



The Supplement to the Tropical Agriculturist 



in five doses. Mention has been made in a pre- 

 vious report of the apparently rapid action of 

 Cattle Manure trenched into the soil as com- 

 pared with the same manure buried with the 

 deep hoe. In order to test this point, cattle 

 manure has been applied on plots 17 and 18 at 

 the rate of 200 maunds per acre, on No. 17 iu 

 trenches and on No. 18 with the deep hoe. The 

 trenches were cut in every row and were 

 approximately eighteen inches deep and five 

 inches wide. The deep hoe was at the rate of 

 twelve noils and penetrated to an average depth 

 of nine inches. The amount of each constituent 

 of these manurial applications has been arranged 

 with no previous knowledge of the precise quan- 

 tities required by the tea bush under various 

 conditions ; it is hoped, however, that the con- 

 tinuation of the experiments on these plots in 

 the manner indicated above will afford valuable 

 information as to the quantities which can be 

 applied most economically. To investigate this 

 matter thoroughly would involve the laying out 

 of a large number of new plots, and it 

 has been decided, in accordance with the 

 opinion expressed by the local advisory Com- 

 mittee, that in view of the difficulty experienced 

 in obtaining the necessary labour to work those 

 plots already in operation, it would be inadvis- 

 able to undertake any further extension at 

 present. Certain plots, however, have been set 

 out for determining, so far as is possible, the 

 amounts of organic manures, such as Oilcakes 

 and Animal Meal, which can most economically 

 be applied : they are arranged as follows : — 



Table of Quantitative Experiment on Oilcake and 



Animal Meal. 







Plot 



No. 



Manure. 



Maunds per acre. 



I 



7 



Animal Meal 



3 



2 



la 



No Manure 





3 



8 



Animal Meal 



5 



i 



8a 



do. do. 



7 



5 



9 



Oilcake 



6 



6 



9a 



No Manure 





7 



10 



Oilcake 



10 



8 



10a 



do. 



15 



It will be seen that the relative amounts of 

 cake and Animal Meal are in the proportion 

 of two to one, this being in accordance with 

 their relative nitrogen content, and also approxi- 

 mately with their cost. *By the kindness of 

 Messrs. Shaw Wallace & Co. I have been able 

 to arrange for the laying out of other experi- 

 mental plots on gardens in their agency, in 

 Assam, in Sylhet, and in the Dooars, and it 

 is hoped that much valuable information will 

 be obtained from these plots as to the varia- 

 tions in quantity of manures required by the 

 differences of climate and soil obtaining in 

 these widely separated districts. 



Potash Salts. 

 Two plots, Nos. 15 and 16, have been set aside 

 for the purpose of determining the value of 

 Potash as an ingredient of manurial mixtures. 



No. 15 has received an application of :— 



Superphosphate - - 3 cwt. 



Sulphate of Potash - - 2 „ 



Oilcake - - - - 5 maunds. 



No. 16 has been similarly treated, the Potash 

 however being omitted. It is probable that 

 Potash is an essential constituent of manurial 

 applications on all soils with but few exceptions, 

 the amount required varying with the compo- 

 sition of the soil, being less on heavy clays than 



on light sandy soils, and in all probability being 

 considerably less than that which has been 

 applied jn many cases where this manure has 

 formed part of a mixture. 



Bone Manuees. 

 The value of Bones for manurial purposes in 

 tea culture has been a matter of considerable 

 doubt, and the absence of reliable statistics 

 bearing on this point has made it advisable to 

 investigate the question. With this object in 

 view a series of plots was laid out at Heeleaka 

 in 1907 and kept under observation during the 

 following season. The manures were applied 

 as follows : — 



Plot No. Manure Rata per acre. 



1. No Manure — 



2. ; inch Bones 1/3 ton 



3. Bone Meal 1/3 „ 



i. Dissolved Bones 8cwt8filb. 



5. Oilcake 4 ,, 72 „ 



fi f Oilcake 1 4 „ 72 



(Superphosphate / 8 „ 80 „ 



The amounts of Oilcake and Superphosphate 

 were regulated to correspond with the nitrogen 

 and phosphate content of the bones. 



Unfortunatoly the tea selected for this experi- 

 ment although apparently even in character, 

 has proved on investigation to be situated on 

 soil of such variable composition as to render the 

 results obtained from these plots unreliable for 

 comparative purposes, on the yield of leaf for 

 one season ; it is therefore proposed to continue 

 the experiment with a view to obtaining infor- 

 mation by observing the variation of each 

 individual plot from year to year, noting any 

 improvement or otherwise, as compared with 

 the behaviour of the unmanured control plot. 

 So far no manurial effect has been observed, 

 which is more or less in accord with the 

 generally received opinion as to the comparative 

 slowness of action of bones as a manure, but 

 it is difficult to understand why no increase of 

 yield should have occurred on"the plot treated 

 with Dissolved Bones. 



Green Manoees. 



As described in the report on this station for 

 1907, the relative merits of five green manuring 

 crops have been tested during three consecutive 

 seasons (1905 to 1907). It is now intended to 

 leave these plots untreated, in order to ascertain 

 the residual effect of the crops grown on them. 

 Plot No. 1, originally unmanured, and No. 4 

 planted with Crotolaria Striata have now been 

 planted with Tephrosia Candida (Boga Medeloa), 

 which will be allowed to remain on one plot for 

 two seasons and on the other for three, the 

 extended use of this plant, and the remarkable 

 results obtained by its growth, making it 

 advisable to determine its value by careful 

 experiment. It is proposed to utilise the 

 remaining green manure plots as starting 

 points for 



FUETHEE EXPEBIMENTS 



on manurial rotation. The effect of green 

 manures on young plants is being tested in 

 the clearance planted out with six months old 

 seedlings in June, 1906. Tephrosia Candida in 

 particular has already produced a marked im- 

 provement in the young plants on that portion 

 of the clearance interplanted with this bush. 

 In addition to the experiments described above 

 certain problems connected with the culture of 



