890 



THE TROPICAL AGRICULTURIST. 



[May I, 1883. 



each pound of i:Iry substance added to the plant by assi- 

 milation during its growth. The amount of evaporation 

 from a cropped soil, however, must always be very vari- 

 able accortUug to season and the nature of the crops. 



With reference to the composition of the drainage- 

 waters we have first of all an analysis of the soil through 

 which the water percolates, and an allusion to the form- 

 ation of nitrates in the soil by the agency of bacterial 

 growths. These act as ferments, o.^idise the ammonia- 

 salts brought down by the rain, and bring about their 

 conversion into nitric acid, the acid then unites with the 

 bases in the soil, such as Unie, forming calcium nitrate, 

 &c. The ferment acts in all fertile soils that are suffici- 

 ently, but not too wet, aud at all temperatures above 

 freezing-point — the maximum energy being evinced at 

 about -61° C. (98 « Fahr.) 



AVhen rain-water, itself containing ammonia, falls on the 

 soil, it dissolves some of the ingredients of the soU, which 

 may be detected in the drainage-water, but fertile soils 

 possess a great retentive power for phosphoric acid, am- 

 monia, and potash, which substances therefore are found 

 ordy in minute quantities in the drainage-water. The com- 

 position of the drainage-water varies very much accortling 

 as the weather is dry or wet. The drainage-water from 

 the relatively drier soil contains about fifteen parts of 

 nitrogen per million in the form of nitrates. After heavy 

 rainfall the quantity of drainage-water is increased, and at 

 the same time the proportion of nitrates is increased. 

 The average amount of nitrogen, calculated as nitrates, 

 per acre, in the drainage-water for twelve months, accord- 

 mg to' the tables here given, amounts to 4.5-.5 lb. from the 

 20-iuch gauge, 36-3 lb. from the 40-iuch, and 43-5 lb. from 

 the 60-inch gauge, so that the loss of nitrogen Ijy drain- 

 age must be considerable when the season is wet. These 

 results, it will be remembered, are from uneropped and 

 mimanm-ed soils. 



"Where manure is applied aud the soil cropped it had 

 been previously ascertained that a large proportion of the 

 nitrogen supphed as manure was not recovered in the crop, 

 nor was it accumulated in the soil. The only conclusion 

 that could be drawn, therefore, was that the nitrogen was 

 washed out of the soil by the rain. To test this lU-ains 

 were laid in each of the e.^tperiraental wheat plots, and 

 a trench cut at right angles to the drains, so that the 

 water flowing from these latter could be readily collected 

 from each plot separately for measurement and analysis. 

 In sutumer-thne, when the field is covered by crop, drain- 

 age rarely takes place, but in October the flow generally 

 begins, to reach a maximum in December aud January. 



The composition of the drainage-water has been ascert- 

 ained by very numerous analyses made at different times 

 by Drs. Voelcker and Frankland, and in the Eothamsted 

 laboratory. We cannot enter into details upon these mat- 

 ■ ters, but it will be readily understood how the time at 

 which the water was collected and the natiu-e of the man- 

 ure employed affect the composition, aud how great is the 

 difference in the composition of the surface water and of 

 that which flows from the saturated soil. AVithout refer- 

 ring to other ingredients, it may be stated that the quant- 

 ity of nitric acid lost by drainage from unmanured but 

 cropped laud, is much smaller than that from uneropped 

 land, the crop assimilating the nitrate formed. The ain- 

 monia of the ammonium .salts is retained by the soil, 

 while the sulphmic acid or chlorine pass off in the drain- 

 age water in combination mth hme. The ammoina is 

 converted into nitric acid almost by the agency of the 

 bacterial ferment alluded to immediately after appUcatiou 

 in wet soils. There is a greater less of nitrogen from the 

 use of nitrate of sodium than from that of a correspond- 

 ing quantity of ammonia. It is interesting also to note 

 the confirmation given of the fact, established in other 

 ways, of the importance of mingling Tvith the ammonia 

 apphed in manures some mineral substances also ; thus, in 

 summer, there is little or no loss of nitrates from the 

 draiimge-water of the ammonia plots if phosphates and 

 potash are supplied with the ammonia, but with an excess 

 of ammonia and a deficiency of ash constituents the ni- 

 trates are imperfectly assimilated by the crop, and appear 

 in the drainage-water. It would thus appear that, except 

 under special circumstances, and for a particular purpose. 



it is not good economy to apply nitrogenous manm'es by 

 themselves, admixture with other material being generally 

 preferable. 



With these general remarks, which will suffice to indic- 

 ate its general tenor, we take leave of this memoir, which 

 is assuredly one of the most important treatises on plant 

 food which has been issued even from Eothamsted. — Gard- 

 eners^ Ckornicle. 



Poor Tea. — There enters into the importations of tea 

 to this country a large amount of adulterated, exhausted, 

 and otherwise impoverished material. English law sfl'ictly 

 prohibits the introduction of such tea into Great Britain, 

 and in 1881, more than 44.000 packages, forbidden entry 

 there, were exported, the most of them to the United 

 States. Among these bogus teas are those that have been 

 aheady steeped aud used, and then worked over for a 

 second use. This is a inatter of great interest to all tea 

 drinkers, a legion among the farmers, and they mil ap- 

 prove the legislation proposed in Congress to exclude 

 those abominable combinations. — American Agriculturist. 



The Japan Radish is thus noticed in the American 

 Ayriculturist :— RaiUshes are the roots most universally eaten 

 by the Japanese. The Japanese radish differs from the 

 American in size, color and taste. It is usually from 1 to 

 li foot in length, and 5 or 6 inches in cu-cumference, but 

 in one of the southern islands it often reaches the enormous 

 length of 5 or 6 feet and weighs several pomids ; the color 

 is generally white and the taste is watery and sweet. It 

 requires a deep soil and rich maniu-ing for its growth. 

 It is mostly planted in August and harvested in December, 

 requh-iug sixty days for its growth, although there are 

 varieties which can be planted even in spring or early 

 summer. Every household uses this root at almost every 

 meal tluroughout the whole year. It is eaten either raw, 

 boiled, or pickled, and may be considered as the great 

 necessary auxihary to the Japanese meal. 



Selangoe fok Planting Enteepeise. — There are no 

 Malay settlements or plantations on the high hills, which 

 are covered with primeval forest ; and I briefly allude to 

 them with a hope that the information may be of use 

 to the coffee planters of Ceylon and other countries, some 

 of whom have ah-eady opened plantations in Selangor at 

 an altitude of 2,500 feet, and whose experience in other 

 climes has favoured the beUef that these hiUs are well 

 smted for Coffea Arabicu, cinchona, ipecacuanha, jalap, 

 tea, &c. ; and they have hitherto been most successful on ' 

 the lower lands in rearing young plants of Liberian coft'ee, 

 cocoa, sago and other tropical products. The rainfall aver- 

 ages about 130 inches per annum, aud due provision is 

 made in the leases to prevent the wholesale felling _ of 

 timber on the summits of hills, such denudation ha\'ing 

 very much affected the rainfall in India, Australia, and 

 other countries. Planters need have . no fear of droughts, 

 as the rains are general throughout the year. — D. D. 

 Dalv in R. Geographical Societi/'s Proceedings, July ISS'2. 



The EtTROPEAN ok English Walnut. — The correspondent 

 who recently asked if the walnut was cultivated in 

 Ceylon wiU find information reg.arding the tree in the 

 folloiving extr.ict from the American AgricvWirist: — The 

 profitable culture of the Engli.sh AValuut in CaUfornia 

 appears to have excited an interest in the tree ^ on this 

 side of the Continent, as shown by our numerous inquiries 

 regarding it. In Em-ope this is known simply as the wal- 

 nut. Our early settlers prefixed the term English to many 

 things they received by the way of the Mother Country, 

 without reference to their origin ; hence we have " English 

 AValnut." It is also called, especially by dealers, the 

 " Madeira Nut." The tree is as much au exotic in England 

 and in Spain as it is with us, it being a native of Persia 

 and other parts of Asia. This wahmt (Jvglans regia) is 

 a relative to our black walnut and butternut, and, like 

 them, forms a large tree ; its leaves are smooth, the sm-face 

 of the nut is rather smooth, aud the husk falls away from 

 it when dry. A remarkable variety originated in France 

 several years ago, called Juglans pro'jMrtvriens. The tree 

 bears large numbers of nuts of good size, with a tender 

 shell, often bearing the third year from the seed. The ti-ee 

 docs not grow very large, and its peculiar character of 

 precocious fruiting is perpetuated by seeds. 



