44 



THE TROPICAL AGRICULTURIST. 



[July i, 1884. 



product, to "improve'' colour. In fact, owing to the 

 demand caused by its being mixed iu this way, long pepper 

 has recently risen about J)s. per cwt. If the grocers wish 

 to avoid another question between them and the analysis, 

 like that of coffee and chicory, or that of mustard and 

 sago flour or other ingredients, they should decline to buy 

 any pepper but that ground from the whole corns for the 

 gain of the substitution of the one for the other would 

 not be worth considering to any individual retailer. 



[The above is taken from the Southern Planter, but is 

 not complete, the copy of that periodical which reached us 

 having been defective. — Ed. T. A.~] 



SCIENCE IN AGRICULTURE. 



BY SIR J. B. I.AWES, BAKT., LL.D., F.B.S. 



In the February number of the Southern Planter I ob- 

 serve some very sensible remarks of Professor Scott, to the 

 effect that science places at the disposal of the farmer 

 the principles upon which his acts are founded, but that 

 his own intelligence and experience must instruct him as 

 to their application ; and he further adds that " every 

 farm is to a certain extent a separate problem." 



About a Quarter of a century ago I published a table 

 giving the relative manure value of a great many of the 

 cattle foods used upon the farm. The construction of the 

 table was very simple. I took the best analyses of the 

 foods which were to be obtained at the time, and deducted 

 from the nitrogen, phosphoric acid, and potash the amount 

 of those constituents which — from my own experiments on 

 feeding — I considered would be assimilated by the animals 

 consuming the foods. I then placed a value on the residue 

 somewhat below the cost for which a manufacturer would 

 furnish a manure in every respect equal in value. 



I have no donbt that the table could be made more 

 perfect at the present time, but with all the increased 

 knowledge which we have acquired in regard to the action 

 of manures, there is nothing to alter in the principle upon 

 which the table was constructed. Decorticated cotton cake 

 would still head the list as furnishing a manure superior 

 to any food used in Great Britain. There are olher foods 

 which have a comparatively low manure value ; aud I no- 

 ticed iu a trade circular not long ago, one rather high 

 priced food which would be almost without any manure 

 value at all._ The cost of a food therefore bears no fixed 

 relation to its manure value. 



At the commencement of the present year an act of 

 Parliament came in force securing to the tenant farmer 

 of Great Britain compensation for the manures applied by 

 them which remained unexhausted at the time of their 

 leaving their farms. 



The act further gives the landlords and tenants the 

 power to form some scale of condensation among them- 

 selves : that is to say, the laud owner and the tenant 

 may come to an agreement between themselves as to the 

 sum which shall be paid the latter on his leaving his farm, 

 as compensation for the cattle food consumed. Both sides 

 in fact contract themselves out of the act; but with this 

 proviso, that the compensation must be fair and reason- 

 able: in other words, the land owner should not put 

 pressure upon his tenant to compel him to sign away 

 his rights. 



It might lie thought that, with some slight revisions and 

 modifications, such a table as that which I had constructed 

 would form the basis of cattle food compensation. Such, 

 however, is not the case, and the popular idea is that some 

 portion of the cost of the food should be the basis of the 

 manure value. 



As this view has been advocated by intelligent farmers 

 who are thoroughly conversant with the contents of the 

 table, I think it will be admitted that the progress of 

 science in agriculture is somewhat slow in this country. 



Your correspondent refers to my having said that sodium 

 supplies the place of potassium when the latter is deficient 

 in the soil. I do not now recollect the exact expression 

 I used when writing on the subject, but I certainly did 

 not wish it to be understood that sodium could perform 

 all the functions of potash. 



We are just now sending a paper to the Royal Society 

 on the composition of wheat grain and straw ; but not- 

 withstanding that in some of our experiments soda has 

 been ustd without potash, aud iu others potash without / 



soda, for twenty years in succession, soda is hardly to be 

 found iu either the grain or the straw. 



When, however, we come to write upon the composition 

 of the ash of pasture grasses, we shall' show that while 

 the grass— when supplied with a sufficient amount of both 

 potash and soda— will always select the former; if it is 

 supplied with the soda alone, it will take up such a large 

 amuuut of that substance that more soda than potash is 

 fouud in the ash. 



These facts may be thoroughly relied upon, as they are 

 based upon the most exhaustive and complete series of 

 ash analysis which have ever been carried out. 



Mangles supplied with soda will take up large amounts 

 of that substance; while potatoes under similar circum- 

 stances do not take up any. The juice of potatoes— where 

 we should expect to find any soluble salts taken up by 

 the plant— contain hardly any soda, even when manured 

 with nitrate of soda. The juice of mangles, on the other 

 hand, under similar circumstances of manuring, contain 

 almost as much soda as potash. 



It is these special properties of different classes of plants 

 that make our attempts to give any exact explanation of 

 the economy derived from a rotation of crops so exceed- 

 ingly difficult. 



There is another peculiar property of plants which re- 

 quires to be thoroughly studied. I allude to the different 

 capacity possessed by different plants for taking food out 

 of a soil. Without at all arguing that red clover derives 

 its nitrogen from nitric acid, I have pointed out that it 

 has greater advantages than any of the other agricultural 

 plants commonly grown 'for taking up a substance which 

 is diffused so rapidly through the soil. It has a longer 

 life, and the plant grows very close together on the soil ; 

 the roots penetrate deep into the subsoil, aud the leaves 

 are always green. If, however, red clover can obtain more 

 nitrogen from the possession of these properties, it might 

 be supposed that they would have enabled it also to col- 

 lect more mineral food. I should certainly have imagined 

 that such would have been the case. 



Let us see, however, what experiment tells us. At Rot- 

 hamsted, between 1850 aud 1873, wheat, turnips, barley, 

 aud beans were grown upon an uumanured soil. In 1S74,' 

 red clover was sown aud the plant was very good, although 

 the crop was small. Between 1873, when the seed was 

 sown, aud June, 1874, when the crop was cut, all the 

 phosphoric acid which it could pick up out of an acre of 

 laud only amounted to 2h lb. ! It may be said that after 

 the removal of so large an amount of crops the soil was 

 exhausted of its phosphoric acid, but such was not the 

 case, as the wheat which followed the clover took out more 

 than 17 lb. of that substance ; while the turnips which 

 followed the wheat fared even worse thau the clover, for 

 they could only obtain 1 J lb. ; but the barley which fol- 

 lowed the turnips took out 10 lb., aud iu 1833— after 3(j 

 uumanured crops had been carried off — the wheat removed 

 20 lb. of phosphoric acid per acre, and produced a crop of 

 29 bushels per acre. 



We get in these results some clue to the conclusions 

 derived from practical experience in all countries, that min- 

 eral manures are much more beneficial to some crops than 

 they are to others. It is evident that the sereal crops 

 possess a greater capacity for obtaining their food from a 

 poor soil than any of the other crops generally grown. 



It is fortunate for the human race that such is the case 

 as nations must have bread to eat without having to be 

 dependent for it upon the aid of science. — Southern Plant,,-. 



FARM MEMORANDA. 

 (From the Leader.) 



A poultry raiser who condemns the incubator in the 

 Hurat New Yorker advocates "bringing chickens up by 

 hand." He places each brood in a small box as soon as 

 they are hatched, and allows them no food for one day. 

 As they increase in size he puts them in larger boxes, and 

 finally allows them to run in a small yard. His hens often 

 hatch four settings of eggs in succession. 



It should be borne in mind that it is just as necessary to 

 ventilate drains as it is to put a vent peg into a cask in 

 addition to the tap, when it is intended to draw liquor ell ; 

 therefore, a square foot or so at the upper ends of the 



