July i, 1884.] 



THE TROPICAL AGRICULTURIST. 



11 



the physical properties of the soil that the universally 

 good results following the application of farmyard manure 

 are to be attributed. Wollny has made some experiments 

 with artificial fertilisers which are worth notice. He mixed 

 clay thoroughly with water, so that the liquid was crowded 

 with innumerable fine particles of the earth. On adding 

 small quantities of ammonia, or of alkaline phosphates or 

 carbonates, to the water the clay is at once precipitated 

 in a dense form. On the other hand, mineral acids and 

 their salts, such as nitrate of soda, act in the opposite 

 way, precipitating the clay, it is true, bui in a light and 

 spongy form, occupying much space. Hence he concludes 

 that the addition of alkaline substances to soils has an 

 unfavorable effect on their porosity had lightness, and con- 

 sequently on their fertility; and he quotes, as cases in 

 point, the alkali plains of Nevada and California, the soil 

 of which is hard, dense non-porous, and sterile. On the 

 other band, such salts as nitrate of soda, sulphate of 

 potash, saltpetre, and kainit produce at once a beneficial 

 effect on the porous character of arable soil ; but the salts 

 mentioned are so quickly washed out in case of rain that 

 the effect is not lasting. Of all artificial fertilisers it is 

 found that lime exercises the most favorable influence on 

 the physical properties of the soil, causing it to aggregate 

 into floculent particles which persist for years, thus making 

 it light, and therefore more fertile. 



MANURIAL VALUE OF DRIED BLOOD. 



A. Petermann's analyses of thirty-two samples of dried 

 blood gave an average of 11 '23 per cent of nitroge»;the 

 physical condition was dry, friable and almost free from 

 smell. To determine the manurial value, plants were grown 

 in pots on two kinds of soil of very different character. 

 On each kind of soil plants were grown with no manure, 

 with blood refuse, and with nitrate of soda, containing 

 nitrogen equivalent to that in the dried blood. The soils 

 consisted in the one case of a loam, in the other of sand. 

 Fifteen pots of each were used, and 10 grains of spring 

 wheat sown in each pot on the 17th March. On the 20th 

 August the plants were removed from the pots, and the 

 straw and grain weighed separately. The tabulated results 

 show that the loam gave the highest yields, but the effect 

 of the manures was greatest on the sand ; in other words, 

 the difference between yields on unmanured and manured 

 sand was greater than between the corresponding loams. 

 In the loam, dried blood produces an increase in the crop 

 practically identical with that given by a quantity of nitrate 

 of soda containing the same amount of nitrogen; the 

 further addition of phosphoric acid or potash, or both, 

 has apparently little effect. In the sand, dried blood is 

 decidedly inferior to its equivalent of nitrate of soda, and 

 both phosphoric acid and potash produce considerable 

 effect ; that of the phosphatic manure, in all the cases in 

 which it was employed, being to hasten the period of 

 ripening. From the results of these and previous experi- 

 ments the nitrogenous manures which have been tried have 

 been arranged in the following order of efficiency, the best 

 being placed first: — Nitrate of soda, dried blood, dissolved 

 wool, wool refuse, leather refuse. The greater the solubility 

 or the readiness to undergo decomposition, the greater 

 the efficiency. 



MANURE FOB BEET EOOT. 



It has recently been again suggested that the beet should 

 be grown in this country as food for stock. The best 

 manure for the full production of sugar in the beet is, 

 according to Holdefleiss, a moderate application of stable 

 manure, supplemented by Ohili saltpetre (nitrate of soda). 

 Manures that are too rich in nitrogen, such as sheep 

 dung, are decidedly injurious, as is also too free an 

 application of Ohili saltpetre. If stable manure is not 

 conveniently obtainable, a mixture of superphosphate with 

 the saltpetre is recommended. 



MANURING EXPERIMENTS WITH RTE AND WHEAT. 



These have beeu made by Marcker in the case of rye, 

 on a good sandy soil, to test the effects of phosphoric 

 acid in bone meal and in purely mineral phosphates, blood 

 meal being added to the latter, and containing as much 

 nitrogen as the bone meal. Five farmers worked in- 

 dependently of each other, and the results came out 

 slightly in favor of the mineral phosphates with blood 

 meal. On light, poor sandy soils the steamed and fer- 

 m;ut'l bone meal gave the best crops. Some plots of 



wheat were dressed with Ohili saltpetre, others with sulph- 

 ate of ammonia. They were applied at different periods, 

 and the saltpetre was found greatly superior, the yield in 

 both grain and straw being considerably larger than on 

 other plots. 



ARTIFICIAL MANURES AND TOTATOES. 



Guradze records results of five experiments on the effects 

 of various chemical manures on the growth of potatoes. 

 The manures were a newly introduced potash-magnesia 

 (containing 50 per cent sulphate of potash and 34 per 

 cent sulphate of magnesia), superphosphate and Ohili 

 saltpetre. The plots received in addition to the artificials 

 a considerable quantity of stable manure. All the crops 

 were exceptionally good, and the plants healthy : the tubers 

 held a good proportion of starch, and the value of the 

 increased production repaid the cost of the extra outlay 

 on manures. The use of artificial fertilisers in growing 

 potatoes is strongly recommended by the experimenter. — 

 Mark-lane Express, 



THE OOOANADA OIL INDUSTRY. 



A gentleman residing in the locality writes to us: — 

 We learn from the Official Review of the Maritime Trade 

 of British India for 1881-82 that, out of a total export of 

 3,009,288 gallons of castor oil, 2,627,923 gallons were ship- 

 ped from Calcutta. Bengal has, therefore, practically the 

 whole trade in castor oil, though the seed from which the 

 oil is obtained is largely imported to that Province from the 

 Madras Presidency. The quantity of castor oil exported in 

 1877-78 was 1,411,216 gallons, so that the increase in the 

 five years ending 1881-82 haa beeu nearly 113 per cent! 

 But the corresponding figures for the export of the oil 

 seed is something marvellous — an increase of 55 fold — from 

 4,521 cwt. in 1877-78 to 250,696 cwt. in 1881-82 ! These large 

 increments have been variously explained. We agree with 

 the view that they are in a great measure due to the con- 

 tinued expansion of the importations of mineral oil, which 

 has now largely displaced castor oil amongst the natives. 

 This account of the matter is supported by the fact of the 

 fall iu the prices of both the oil and the seed, when com- 

 pared with those of previous years. The reduction in price 

 is specially noticeable from a comparison of the Trade Returns 

 of 1880-81 and 1881-82. Wethere find thatwhilethe exports 

 of castor oil for the latter year exceed those of the former by 

 118,485 gallons, their total value was less by Rl,27,579. Simil- 

 arly, with castor seed for thesame periods, the shipments show 

 the large increase of 228 per cent in quantity, but only 171 

 per cent in value. These marked differences cannot, how- 

 ever, be wholly due to the extended use in the country of 

 the cheap, foreign illuminating agent, Kerosine. For it must 

 be remembered that the demand for castor oil on the Ind- 

 ian Railways — both for lighting and lubricating — has risen 

 manyfold in recent years. "Inoreased production" must 

 therefore be a factor in the increasing exportation of oil 

 and seed as well as in the rapid decline in their average 

 prices. It is interesting to note that the export of oil-cake 

 is not in proportion to that of oil, being much below what 

 might be expected !rom the increased exportation of oil. 

 This shows that the advantages of using this article are 

 coming to be understood and appreciated by the Indian 

 ryot, who is wise in utilising a waste product for the en- 

 richment of his own lands, and in not allowing it to go, 

 as heretofore, to benefit in like respect the Colonial Planter, 

 who was by this means enabled to out rival him in other 

 products. The heavy reduction in the price of this article 

 from R50 in 1880-81 to R40 in 1881-82 per ton may be 

 ascribed to the falling-off in the demand from Ceylon; 

 because Brazilian coffee is taking the place of the Ceylon 

 berry in the markets of the West. The demand, however, 

 from the sugar planters of Mauritius and the Straits of 

 Java still continues brisk, and the West Indies, via the 

 United Kingdom, bid fair to become our best customers. 

 The foreign export of castor oil from the Madras Presid- 

 ency (which has 67,000 acres under this crop), in 1881-82 

 was 205,274 gallons, and that of seed 172,536 cwt. And as 

 no inconsiderable portion of these quantities are contrib- 

 uted by the Godavery District, besides its enormous seed 

 shipments to Calcutta from Oocanada, a few words relative 

 to the oil-mill industry in the latter locality may not be 

 devoid of interest or unacceptable to our readers. 



