02 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



remains open and a crust cannot form. Sur- 

 face cultivation by mixing the mulch of manure 

 with the soil allows a crust to form after irriga- 

 tion and the yield is considerably reduced. 

 • (d) The number of cuts obtained from a shaftal crop, 

 other things being equal, depends on the pre- 

 sence of aerating materials in the soil. 



The importance of soil aeration in the growing of these 

 crops was confirmed during the year by the results of a 

 series of aeration experiments with lucerne and shaftal. 

 The origin of these experiments is a matter of some interest. 

 In 1917, during a visit to the Mustung valley in the Kalat 

 State, the great difference between the health and vigour of 

 the wheat and other crops near Mustung compared with 

 those in the Quetta valley was very marked. The difference 

 appeared to be due to the admixture of the Mustung soil 

 with fine wind-blown sand carried into the valley from the 

 desert to the west- Samples of this wind-blown sand were 

 obtained and cultures were started of. mixtures of Quetta 

 soil and various aerating agents including this desert sand. 

 The results obtained were very striking. An admixture of 

 50 per cent, of the wind-blown sand to Quetta soil increased 

 the yield of lucerne by 42 per cent. These experiments are 

 being continued and will be published in due course. The 

 improvement in the physical texture of the soil of the 

 Mustung valley brought about by this wind-blown sand 

 would also explain the reputation for quality this locality 

 has achieved in such crops as wheat, tobacco and melons. 

 The admixture with sand improves the aeration of the soil 

 and this in turn influences the development of quality. One 

 possible means of improving the Quetta soil would be by the 

 admixture of finely ground ashes which are available in 

 large quantities near the railway station. Some of this 

 waste product is being ground up in a mortar mill and will 

 be applied to the land this year- For vegetables and crops 

 like lucerne, ground ashes might act as a very useful manure. 

 The trials of baled shaftal by the Army at Quetta, which 

 were referred to in the last report, were duly completed and 



