254 



[April 1907. 



Correspondence. 



MULCH AND CAPILLARITY. 



Sir,— The true signification of the word mulch is, strange to say, not under- 

 stood by many practical agriculturists, and even " The Times " does not seem to be 

 quite clear on the subject, to judge from the extract given by Mr. Biddulph on page 

 510 of the " T.A." for December last. In this passage there are one or two state- 

 ments to which I would take exception. 



1. " Very roughly speaking it (mulching) is that light caking of surface soil 

 which protects the soil beneath." Now the caking of the surface soil is just that 

 condition which favours surface evaporation and makes a mulch necessary, and the 

 easiest Avay this is prevented is by breaking tip the surface soil and leaving 

 a loose superficial layer. Ifc is by the " settling down" of the topmost layer that the 

 " capillary tubes" are brought to the surface, and loss of water occurs by evaporation. 



2. "To mulch is to beat stuff together into a compost without binding it." 

 This, to say the least, is an extraordinary definition, and no one is likely to learn 

 how to take advantage of the process of mulching by reading it. I would say that 

 to mulch is to provide a surface covering consisting of some transported materials, 

 such as straw, decayed leaves, coir dust, &c, or of a loose dressing of soil provided 

 in situ by frequent stirring of the topmost layer. 



The question raised by Mr. Biddulph as to the nature of capillary tubes is 

 answered in a few words. " Capillary tubes," per se, are tubes (of any material) of 

 such calibre (comparable in fineness to that of a hair-capita) as gives them the pro- 

 perty of capillary attraction for fluids such as water, i.e., the property of " sucking 

 up" water when brought in contact with them. Inversely, water in contact 

 with such tubes rises up by capillary attraction. These must be accepted as physical 

 facts which call for no explanation here.— Now, when soils are in the best mechanical 

 condition, neither too loose not too dense, they provide the best condition for the 

 formation of capillary tubes which, however, are not of typical structure, 

 i.e., straight and uniform, but are passages formed (as the Editor of the " T. A " 

 pointed out) by a series of the interspaces between soil particles, and offering the 

 same conditions for water attraction as typical capillary tubes provide. 



Yours truly, 



C. DRIEBERG. 



Colombo, 14th March, 1907. 



Minutes of the Board of Agriculture. 



The Thirtieth Meeting of the Board of Agriculture was held at the Council 

 Chamber at noon on Monday, the 8th April, 1907. 

 His Excellency the Governor presided. 



The others present were :-The Hon. Mr. W. H. Brodhurst, the Hon. Mr. 

 C. T. D. Vigors, the Hon. Mr. H. L. Crawford, C.M.G., the Hon. Mr. S. C. Obeyesekere, 

 the Hon. Mr. A. Kanagasabai, the Hon. Mr. J. Ferguson, C.M.G., Dr. J. C. Willis, 

 Messrs. J. Harward, W. D. Gibbon, R. Morison, E. T. Hoole, and C, Drieberg 



(Secretary), 



Visitor ;— M. Supparamaniamt 



