Edible Products. 



506 



Decembeb, 1909. 



in practice proved that the deficiencies 

 of the soil could not be supplied by 

 laboratory experiments alone. Soil 

 analyses, chemical and mechanical, and 

 analyses of the tea plant undoubtedly 

 help in providing the planter with a 

 knowledge of the bush's requirements, 

 but the only true results are to be 

 obtained from actual field experiments. 



All good tea soils contain a vast 

 quantity of potential plant-food which 

 by careful tilling can be converted into 

 available plant-food. "Fertilisers are 

 unnecessary on newly opened out land, 

 but after a few years the soil refuses to 

 yield good crops by cultivation alone, so 

 we are compelled, if we are to Keep up 

 our outturn, to supplement the store of 

 available food. 



The planter, by careful cultivation, 

 economises the natural store of plant- 

 food, but it is also good planting practice 

 to judiciously supplement the easily 

 exhausted constituents of the soil. Un- 

 less the bushes are kept up by artificial 

 restoration, the yield must gradually 

 diminish and the production sink to a 

 low ebb. When the soil gets partially 

 exhausted the annual quantity of pre- 

 sently assimilated food is insufficient, 

 even under the best cultivation, to 

 produce a maximum crop of good 

 quality. 



The Doctrine op Economy. 

 No fertilisers should be imported until 

 all available manure about the estate is 

 used up, and it must always be borne 

 in mind that many manures may be 

 purchased at too great a cost ; therefore, 

 experiments must be carried out and 

 discretion used when introducing new 

 manures. There is a sad waste of cattle 

 manure on many estates, through neglect 

 of ordinary precautious, but the planter 

 is now beginning to realise the great 

 gain through the use of roofed pits, and 

 by covering manure with layers of soil 

 or succulent jungle when this is procur- 

 able. Serviceable pits do not cost much 

 to make, and should be roofed with 

 thatch or corrugated iron ; old coolies, 

 who are unable to perform ordinary 

 tasks, are often available for the work 

 of collecting. Manure should be daily 

 collected and pitted to avoid waste of 

 the most valuable ingredients. 



Dr. Dyer, writing on the subject of 

 "Manure Preservation," says:— "Other 

 methods of preservation described, less 

 simple, but nevertheless easy to carry 

 out, are to sprinkle the dung, as it is 

 produced, with materials which, like 

 superphosphate and gypsum, shall act 

 as fixers or absorbants of ammonia ; or 

 which, like kainit, shall act as anti- 



septics, or preservers of the dung from 

 speedy fermentation. The former pro- 

 duces a fairly ripened manure suited to 

 clay soils poor in humus or organic 

 matter ; while the latter are recommend- 

 ed for the preservation of dung for light 

 and open land, on which it is desirable 

 that it shall be applied ' long' or unrotted. 

 If the former method of chemical treat- 

 ment be adopted, a mixture should be 

 made of equal parts of superphosphate 

 and gypsum, and about I5 lb. or 2 lb. a 

 day, per head of stock, should be 

 sprinkled amongst the dung. If, on the 

 other hand, kainit be used as an anti- 

 septic, about 2 lb. per head per day 

 should be strewn on it. The immense 

 superiority of manure prepared in either 

 of these ways to manure heaped without 

 these precautions has also been proved 

 not only by analyses but by experiments 

 in the field. It may be added that unless 

 proper care is taken in the making and 

 preserving of dung, the sooner it goes on 

 to the land the better." 



The use of heavy dressings (over eight 

 tons per acre) of cattle manure to tea 

 land, unless to benefit the soil mechani- 

 cally, is not to be recommended, better 

 results being obtained from the use of 

 moderate dressings supplemented by 

 concentrated fertilisers. 



In otherwise good tea land, one of the 

 three essentials — nitrogen, phosphoric 

 acid, or potash — may be temporarily 

 exhausted and thus render the soil in- 

 capable of carrying its maximum crop. 

 If the planter by observation or experi- 

 ment is able to recognise which form of 

 plant-food is needed, he can by the use 

 of the particular artificial manure force 

 a good crop, provided, of course, that the 

 soil is otherwise in good condition. It is 

 not only necessary for the planter to 

 know what manures to apply, but also 

 the quantities and best time of appli- 

 cation. In the writer's opinion the 

 nitrogenous manures used in the 

 Heeleaka experiments ought to be 

 applied in smaller quantities at frequent 

 intervals, but, as with our other tea 

 problems, this can only be proved by a 

 series of experiments. The best results 

 so far obtained in tea manuring have 

 been from the use of catt.e manure, 

 oilcakes, and sterilised animal meal, but 

 as these cannot be had iu sufficient 

 quantities, we shall in time be compelled 

 to go in more largely for mineral 

 manures. 



Mineral Manures. 

 Nitrate of soda and sulphate of am- 

 monia are two of the most likely of the 

 nitrogenous mineral manures to give 

 beneficial results, but sulphate of am- 

 monia is slower than nitrate of soda in 



