THE 



TROPICAL AGRICULTURIST 



AND 



MAGAZINE OF THE 



CEYLON AGRICULTURAL SOCIETY. 



Vol. XXXII. COLOMBO, OCTOBEE 15th, 1908, Wo. 4-. 



Cleanliness of Cultivation. 



A great deal of nonsense, or of irrele- 

 vant matter, is uttered on this topic. 

 Really what it comes to is whether 

 complete cleanliness, or clean weeding, 

 is worth while. The question has been 

 brought into great prominence by the 

 enormous expenditure on weeding in- 

 curred upon many rubber estates, on 

 which, clean weeding is often costing 

 two or three times as much as on a tea 

 estate, where the cost is already heavy 

 enough in all conscience. 



For places where machinery can be 

 used to weed, there is little doubt that 

 clean Aveeding is cheap and effective, but 

 less as weeding than as tilth. Where 

 the ground is kept well tilled, the weeds 

 do not spring so vigorously, the soil 

 remains moist, and renews its water 

 supply from below. Whereas in the 

 southern part of Ceylon, the soil is not 

 tilled, its water supply would seem to 

 come mainly from above, and a short 

 drought soon makes itself felt. Water 

 evaporates more rapidly from a hard soil 

 than from a tilled soil. This is a point 

 which seems very difficult of comprehen- 

 sion in this country. 



Where the land is covered with such 

 permanent crops as tea, leaving too 

 little room for machine tillage (even if 

 such were possible on the hilly and 

 rocky ground of much of the planting 

 country), the best thing is probably to 

 grow selected weeds. These may with 

 great advantage belong to the family 

 Leguminosae, for then they improve 

 the contents of the soil in nitrogen. 

 Such are Crotalarias, Parochetus, Des- 

 modium, and the rest. They should be 

 cut at the flowering stage, and the cut 

 stuff used as a mulch. Other green 

 manures are such things as Passiflora 

 fcetida, a common (American) weed in 

 Ceylon, which will, it appears, grow 

 very well flat on the ground and thus 

 keep down other weeds, while being itself 

 easily rolled up. It must, however, be 

 pointed out that more water evaporates 

 from a soil covered with plants than from 

 a naked tilled soil, so that in dry places 

 the clean weeding is probably the better. 



We have for years maintained that 

 machinery must sooner or later replace 

 much of the hand labour now being 

 done in'^Ceylon, and there is no doubt 



