Notes. 195 



too strong-ly. It is emphasized in tlie following extract from the 

 report of the Commission already referred to: — 



" Your Commission recog-nizes that there are those who will 

 consider any measure of compulsion with reference to the jackal 

 irksome; but the benefits which will flow to both State and farmer 

 as a result of the extermination of the jackal, far outweig-h any 

 inconvenience to which the farmer may be put. To the farmer the 

 extermination of the jackal means large savings in the cost of herd- 

 ing his flocks; more and better wool; a greater freedom from stock 

 disease and attacks by insect pests; greater protection from scab; 

 and an increased capacity of the farm to carry stock. To the State 

 the extermination of the jackal means that the destruction of the 

 vegetal covering of the country and soil erosion will cease, in so 

 far as the kraaling of stock is responsible; that it will be possible to 

 introduce the paddock system of farming, and through that bring 

 about the restoration of the veld, which at the present time is in the 

 process of ruination." 



This statement should induce every farmer in the affected parts 

 to contribute his share (however meagre it may be) to the accumu- 

 lated data from which the best methods of ridding a dangerous 

 menace to the State may be devised. 



Tree-planting and Soil Fertility. 



There is no more commendable practice than that of tree-planting, 

 particularly in a country such as ours, and the planting of belts and 

 clumos of trees providing shade and shelter for the farm animals that 

 is being carried out at present in Natal and other T)arts of the Union 

 could be widely extended with benefit to man and beast. In connec- 

 tion with this practice, Mr. Williams, the Chemist at the Cedara 

 School of Agriculture, draws attention to a noticeable feature : it is 

 found that, as a rule, the soil contiguous to these trees, xiv> to a maxi- 

 mum distance roughlv of 20 yards, is apparently infertile, for little 

 in the way of crons will grow there, such growth as there is improving 

 progressively with distance from the trees until they attain normality at 

 the limit of the area. There are se^;eral causes that are ffiven for the 

 unprofitable state of this zone, and they are discussed by Mr. "Williams 

 in an article appearing in this number of the Jcnirnal entitled 

 " ADoarent Infertility of the Soil around Trees." The matter has 

 been the subject of experiments at Cedara, and they go to show that 

 the scientific contention that the main reason for the barrenness of 

 the l^nd in proximity to a plantation is the deprivation of the trees 

 of the moisture of the soil through which their roots rauGe, appears 

 well founded. The deep-rooted trees are able to obtain their moisture 

 at a considerable depth in the sub-soil, but this would deplete the 

 underground supply of water so as to prevent a sufficient amount 

 beinos" drawn up to near the surface by capillary action for the needs 

 of the neio-hbourino- shallow-rooted crop. It has been found in 

 California that the blue-gum, which has been largely used for wind- 

 breaks, has this effect on to the soil to a distance of about 30 fee;t on 

 either side, and that on that account the pine and cypress have 

 recently supplanted the gum, for their narrow type of leaf conduces 

 to a minimum amount of transpiration and loss of soil moisture as 

 opposed to the action of the broad leaf of the gum. 



U 



