174 



MAGNKSIA IMPREGNATED SOILS. 



Comparing field results Avith laboratory analyses, Dyer's 

 method certainly appears to afford a good indication as to 

 the relative availability of the lime and magnesia. Although 

 one cannot justifiably be dogmatic, yet from the experience 

 gained one is able noAv to predict with a fair degree of 

 accuracy in the case of the virgin soils of the Great Dyke 

 the returns of maize — the staple crop on the heavier soils of 

 this territory — Avliich are likely to be obtained. 



Rocks, Sou s axd General I'eatcres of the Great Dyke. 



The soils of the Great Dyke are red, chocolate and black 

 loams, the black being the heavier in character and situated 

 in the vleis, and the red and chocolate on the slopes. 



Although the crop returns on many of the soils sitiiated 

 on the Great Dyke have been unsatisfactory, the veld in those 

 areas with which I am familiar is covered Avith a rich growth 

 of sweet grass, which affords excellent grazing for cattle, 

 and, with its plentiful supply of good Avater, the country is 

 undoubtedly excellent for stock farming. 



On some of the Great Dyke soils, more j^articularly those 

 derived from the norite formation, some veiy fair returns 

 of maize liaA'e been obtained, and the fact that the natural 

 herbage is so good throughout leads one to hope that crops 

 of economic importance and improA-ed economic methods of 

 soil treatment will be found that Avill prove suitable for those 

 soils of the Great Dyke Avhich have been less productive in 

 the past. 



As Avill be appreciated from the following results of 

 analyses of specimens of norite. enstatitite and serpentine 

 obtained from the Great Dyke formation, the composition of 

 the Dyke soils deriA'ed from norite are richer in lime than 

 those which result from the Aveathering of serpentine and 

 enstatitite. This feature is of particular interest, because 

 it has enabled us to compare field returns on Dyke soils of 

 A-arious lime-magnesia ratios. 



Soda, etc.. not determined. 



