Vol. IX. No. 218. 



THE AGRICULTURAL NEWS. 



279 



PROGRESS REPORT ON THE EXPERIMEXT- 

 AL AGRICULTURAL WORK OF THE DEPART- 

 MENT OF SCIENCE AND AGRU'ULTURE, BRIT- 

 ISH GUIANA. APRIL V.kjS TO OCTOBER 1909. 



The work described in this report was undertaken, under 

 the auspices of the Department of Scietice and Agriculture, 

 British Guiana, at the Botanic Garden, the Onderneeniing 

 School Farm, the Is.sorora Rubber Farm (under the general 

 supervision of the Government Agent of the North Western 

 District), the rubber and forestry station at Pin. Christian- 

 burg, Deraerara Itiver, and at the Kubber Experiment 

 Station at Bonasika Reserve. Plans for the establishment 

 of an e.vperiment station near Marlborough, Pomeroon Itiver, 

 are being considered by the Government. 



In the work in raising canes from seed, much trouble 

 was experienced at one time through damping off during the 

 heavy rains; a remedy was found in thoroughly watering the 

 soil in the seed boxes with a mixture of nitric acid with 

 water, containing 2 oz. of the acid in 1 gallon of water, the 

 soil being treated sub-sequently with water alone in order to 

 remove exce.ssive acidity. In .January and February 1909, 

 about 5-5,000 cuttings of the more valuable .seedling canes 

 were distributed to a few planters. Other promising vari- 

 eties were planted out for manurial variety experiments, and 

 these are intended to be used, partly, for making comparison 

 of the value of calcium cyanamide and calcium nitrate, as 

 manures, with that of the older nitrogenous manures. The 

 experiments connected with cane-arrowing and seed-sowing, 

 in 1908, showed that the seeds of arrows from the Bourbon 

 variety were the most fertile, followed in order by D 109 

 D.U5, D.4805, D.147, D.2468 and B.208. 



The manurial experiments with nitrogenous manures, in 

 connexion with sugar-cane, showed that when nitrate of soda 

 follows sulphate of ammonia, the latter having been used for 

 some time on unlimed land, a reduction of the increased yield 

 that had been obtained already was experienced. When the 

 positions were reversed— sulphate of ammonia following 

 nitrate of soda— an increased yield was obtained. Similar 

 results were gained on limed land. The following conclusion 

 from these trials is made: The results clearly indicate that on 

 very heavy clay soil, such as that of the Experimental Field, 

 iind under tropical meteorological conditions, the deHoccuIation 

 or puddling caused by long-continued dressings of nitrate 

 of soda is likely to prove more injurious to the soil 

 than is the souring action of sulphate of ammonia. The 

 trials with phosphates are not yet complete, on account of 

 the numerous comparisons that are required in order to 

 obtain a definite result, Increases of yield are still usually 

 obtained from an application of lime, to certain plot.s, in 1891, 

 but there are indications that the eti'ects of the liming are 

 almost exhausted. 



As a result of the trials of the new varieties of sugar- 

 cane, information lias been obtained as to the ceneral 



influence of the female parent on the crop and sugar yields. 

 These are stated to have no relation to the female ancestry of 

 the cane. Other interesting results in connexion with the 

 manurial trials of all the varieties are: that readily available 

 nitrogen has the most potent effect on the yields; that nitrate 

 of soda has not been as satisfactory as a manure, as sulphate 

 of ammonia; that D.1082, I).1119 and D.790 were the 

 best plants, and D.45, D.1082 and D.75.5 were the best 

 first ratoons under the conditions in the Briekdam Field and 

 the North- West Field, respectively. As before, B.208 has 

 shown a preference for the lighter soils, while its juice was, 

 as usual, notably high in sucrose and purity. Tests of 

 a larger number of the newer varieties, in the experimental 

 field-s, indicated that several of these may become of consider- 

 able value 



Trials with nitro-bacterine .specially prepared for use in 

 connexion with the cultivation of sugar-cane, whether in 

 plots or pots, showed that no effects were produced by 

 the use of this preparation. 



The continuation of investigations into the composition 

 of the soil and subsoil waters of the experimental fields con- 

 firmed the results obtained formerly, namelj', that in the wet 

 season, a great increase in ammoniacal, and a decrease in 

 nitric, nitrogen takes place, the comparison being made with 

 the amounts of these present in the dry season. An experiment 

 to find the composition of water taken at a depth of 12 feet 

 below the surface of the soil showed, particularly, that the 

 proportion of nitrogen pre.sent in it, in the form of ammonia 

 and organic matter, was high when compared with that 

 present as nitrates. It was decided to make an investigation 

 for the purpose of finding a probable cause of the low fertility 

 of the land from which ihe samples for these experiments 

 were taken, and the result was to indicate that this lower 

 fertility was probably due to the extent to which magnesium 

 salts are pre.sent, in comparison with the content of calcium 

 .salts. 



Information relating to the quantities of salts, etc., 

 contained in the lower layer of the soil, and in the subsoil, 

 indicates unmistakably the relatively large extent to which 

 .soluble salts useless to plant.s, and some even poisonous to 

 them, are present in these, in the experimental fields. An 

 enquiry into the evaporation of the soil water in air, and in 

 carbon dioxide, is of some interest. It shows that the presence 

 of the latter, to its proper extent, in the soil, modifies the 

 poisonous action of the magnesium salts present in the soil 

 water, and indicates the great importance of the maintenance 

 of the supply of humus in tropical soils. 



Among the results obtained in the rice experiments are 

 the following: (I) that applications of sulphate of potash and 

 lime during 1908 gave increases of yield; (2) that it is necess- 

 ary to use pure seed paddy if the maximum crop of any one 

 kind of rice is to be obtained; (.3) that on soils such as those 

 of the Experimental Field, though as yet no advantage of single 

 planting over multiple planting has been indicated, the 

 number of plants in a bunch may be reduced to about two or 

 three without lessening the chances of obtaining a maximum 

 crop. As regards cotton, accounts of trials with different 

 varieties, and a report on several indigenous cottons, are 

 given, and it is stated that Caravonica silk cotton has shown 

 itself unworthy of adoption for cultivation in British Guiana. 



The report concludes with particulars of interesting 

 experiments with bananas, cacao, coffee, limes and other 

 fruits, miscellaneous products and rubber, the enumeration 

 of which the space at disposal does not permit. 



