Vol. XL No. 269. 



THE AGRICULTURAL NEWS. 



259 



Interesting general conclusions were obtained in 

 regard to the tlonil type of the soils It seems that 

 this is influenced to a greater extent by the local 

 climate, situation and management than by the soil 

 itself; the last may, however, become a dominant factor 

 under the influence of i.he kind of management, which 

 itself is a potent cause in determining the floral type 

 that may obtain. Turning from this to the considera- 

 tion of the relation between the habit of growth 

 of the plants, their chemical composition and their 

 feeding value, it was found that the variations 

 in the last of these could not be explained by those 

 in the composition, though certain constant differ- 

 ences were observed, particularly the fact that the 

 herbage from the better fields was almost invari- 

 ably richer in nitrogen — a matter that may be 

 expected from the higher nitrate content of the 

 soil. Determinations of the proportion of nitrogen 

 in the herbage that could be dissolved by the 

 action of pepsin also showed small differences, for there 

 was always a larger total amount of digestible nitrogen 

 in that from the better fields. It was noticed that 

 there was invariably a larger propurtion of manganese 

 oxide in the poorer herbage, and this was almost alwa^'s 

 the case in the less productive soil, but present know- 

 ledge of the part taken by manganese in plant and 

 animal life does not permit it to be stated if this fact 

 possesses any significance. It is concluded from the 

 whole matter that the method of food analysis, as this 

 is carried out ordinarily, fails to iiidicaie the value 

 of grasses as food. 



It is evident that, under the conditions described, 

 the feeding value of pasture grass is determined rather 

 by the habit of growth than by the floral type, the 

 latter being decided by surrounding circumstances 

 rather than by the food-supply, while the habit of 

 growth is influenced by factors that are more difficult to 

 ascertain: under the conditions of the investigation, 

 the most important of these factors seem to be the 

 ease of decomposition of the organic matter and there- 

 fore the rate of formation of nitrates and ammonia, the 

 supply of phosphate being also important. This leads 

 to the conclusion that floral type and habit of growth 

 are independeut.so that where attempts are being made 

 to improve a pasture, it must be determined, first, 

 which of these is the cause of its infertility. Lastlv, 

 the ordinary methods of investigation are inadequate 

 for ascertaining the value of pastures, while it seems 

 likely that the best herbage will grow on soils in which 

 the texture is best, and therefore the power to drain, 



as well as to hold water is well marked; though with 

 regard to this matter, soil analysis does not give as 

 definite indications for pasture land as for arable land. 



CEMENT FOR CAVITIES IN TREES. 



The subject of the preservation of trees received 

 attention in an article on page 251 of the last number 

 of the Agricultural Neivs. The additional informatioa 

 given below is taken from the Garden and Field for 

 May 1912. 



It is only recently that very much attention has been 

 given to the filling of cavities in trees This is now being 

 done quite extensively, and better work is being accom- 

 plished in this line than heretofore. 



The question has often been asked whether it is worth 

 while to dig out a decayed cavity of a tree and fill it with 

 cement or some similar substance. We are free to confess 

 that we have never had an opportunity to examine many 

 trees wliich have been filled for any length of time, 

 especially when the filling was well done, and therefore have 

 not sufficient data to ascertain whether this method of treat- 

 ing tiees always prevents further decay. Until we have 

 an opportunity to examine carefully specimens that have 

 been filled for many years, we cannot be absolutely sure 

 whether the types of filling now in vogue are successful in 

 preventing further decay. 



We have observed sections of large trees which have 

 been filled for a few years, which showed that decay was not 

 arrested completely, but it is hardly fair to assume that the 

 trees we examined represented the best workmanship in this 

 direction. Wc believe, however, that if a rotten cavity is 

 thoroughly cleaned out and properly filled, the life of a tree 

 can be greatly extended, and that it is possible to prevent 

 further decay of such cavities. The best method, however, 

 of treating tree cavities may not as yet have been discovered, 

 AVe believe that it is the best plan to make all cavities 

 wider at the centre than at the exterior surface, so that the 

 filling substance will be wedged in, as it were, and have no 

 opportunity to fall out or become displa-ied. 



Of course, cavities after being thoroughly cleaned are 

 treated with some antiseptic, such as corrosive sublimate, 

 creasote. or paint Creasote possesses more penetrating 

 power than a water}' solution of corrosive sublimate, and 

 probably for this reason it is more effectual in reaching por- 

 tions of the mycelium of the fungi which might be still 

 remaining in the wood near the chiselled surface. Probably 

 formalin at the rate of 2 to 4 parts of formalin to 100 

 parts of water, as well as many other substances, can be 

 used to advantage, but the use of such disinfectants on trees 

 is entirely in an experimental stage, and their value as anti- 

 septics is problematical. 



DEPARTMENT NEWS. 



The Imperial Commissioner of Agriculture left 

 Barbados on July 80, by the S.S. 'Guiana', on an official 

 visit to the Northern Islands. It was intended that 

 Dr. Watts should spend some time in St. Kitts and 

 Dominica, and return to Barbados by the S.S. 'Oruro' 

 on August 21. 



