February, 1912.] 



105 



Oils and Fats, 



of the roots is limited to the surface, and 

 the palms are more readily blown over 

 by the wind. Sheltered valleys should 

 also be avoided, though the poor yields 

 from inland plantations can be largely 

 attributed to the lack of water in the 

 subsoil, too close planting and the 

 apparent indifference of the native 

 planters towards any improvement 

 either in thb way of thinning out the 

 trees, or by undertaking some form of 

 cultivation to produce a more friable 

 condition of the soil.* By adopting 

 scientific methods of cultivation the 

 environment of our economic plants has 

 been greatly extended, and it is possible 

 to create conditions under which these 

 plants thrive just as well as in Nature, 

 and in many cases far better. So one 

 hopes to extend the region of coconut 

 culture from the coastal areas to the in- 

 land districts through due attention to 

 seed selection, irrigation and drainage, 

 planting in orchard form, so as to have 

 the maximum amount of light and air, 

 and regular cultivation and manuring 

 to restore tne plant-foods removed by 

 each hardest of nuts. 



In the August, September and October 

 numbers of Iropical Life several in- 

 teresting articles dealing with coconut 

 palms have appeared, and so, to avoid 

 repetition of the information given 

 there, we shall confine our attention 

 to the manuring question. Those 

 acquainted with coconut plantations 

 are quite aware that the trees in the 

 neighbourhood of the stations are fre- 

 quently more vigorous and produce 

 larger crops than those even a few 

 hundred yards distant. The natives 

 attribute the larger return of nuts to a 

 form of gratitude on the part of the 

 trees for their iuclusion in the family 

 circle, but the real reason lies in the fact 

 that such trees get more attention in 

 the way of manure from the cattle sheds 

 and other refuse of a fertilizing charac- 

 ter. Not only is a higher yield notice- 

 able, but the nuts are larger, and young 

 trees on the plantations near the stations 

 come earlier into bearing and yield even 

 at their fifth or sixth year ; whereas, 

 in ordinary cases, a period of from eight 

 to ten years usually elapses before the 

 trees produce nuts. This is by no means 

 a small consideration, for a quicker 

 return on the outlay is thus assured. 

 Experiments on the manuring of coco- 

 nut palms have not yet been conducted 

 on any large scale, and up to the present 

 we have only the guidance of the ana- 

 lyses of the various products removed 



* See "Notes on Cultivation" in Tropical 

 Life for October, p. 200. 



14 



by a year's harvest. Dr. Backofen has 

 shown by analyses that a crop of 1,000 

 nuts, i.e., the produce of half an acre, 

 removes the following quantities of 

 plant-food from the soil :— 



Nitrogen ... ... 8-6 lb. 



Phosphoric Acid ... 2'4 „ 



Potash 187 „ 



Lime ... ... 2*3 ,, 



Salt 21-4 „ 



making a total of 53*4 lb. of plant-foods 

 removed from the soil of half an acre by 

 the crop alone, and besides this the trees 

 have also to be considered and provided 

 for. 



These figures give us a working basis 

 on which we can build up a manure 

 mixture to replenish the soil with the 

 more important plant-foods. Assuming 

 that fifty trees go to the acre, and that 

 the average harvest is fifty nuts per tree, 

 then this means that 21£ lb. nitrogen, 6 

 lb. phosphoric acid, and 471b. potash are 

 removed. These figures are taken from 

 the analysis of the nuts, and allowing 

 for the growth of, and nourishment for, 

 the trees, we arrive at the following 

 figures :-- 



Nitrogen 29 lb. 



Phosphoric Acid ... 14 ,, 

 Potash ... ... 74 ,, 



Before dedueing a suitable manure- 

 mixture from these figures we must take 

 certain consideratione into account. 

 The palms are known to be heavy 

 feeders, but if found under suitable soil 

 conditions, then the roots have a wider 

 ranging power, and can draw to a 

 greater extent on the original or latent 

 supply of plant-food in the soil. Then, 

 on a young plantation, it is assumed that 

 suitable method of cultivation will be 

 adopted, and for the first two or three 

 years catch crops of marketable value, 

 such as corn and mountain rice, may be 

 grown between the lines. The yields 

 from these catch crops will usually 

 balance the cost of cultivation, but after 

 the fourth year the leaves of the palms 

 will have spread over the rows suffi- 

 ciently to create too dense a shade for 

 catch crops. Cattle manure is rarely 

 found in sufficient quantities for large 

 plantations, and to supply humus, which 

 is useful to conserve the moisture in the 

 soil, a legume crop, such as velvet beans 

 or cow peas can be grown, and this, 

 when lightly ploughed under, supplies 

 the soil with nitrogen, which the bac- 

 teria on the roots have the power of 

 building up from the free nitrogen in 

 the atmosphere. On a fairly heavy soil 

 a legume crop is of considerable value, 

 since roots open up and cerate the soil, 



