Journal of Agriculture. [i i Jan., 1909. 



eighty parts per 100,000 ; that is approximately the same amount as is- 

 found in the yellow slaty rock which forms the basis of many of the hills. 

 The potash is nearly always high, this again being a characteristic witlx 

 both the slate and the granitic ruck. .Nitrogen is compaa-atively po^r, but 

 owing to the relative ai)undance of the other plant foods, it is very easy 

 to make up the deficiency by the growth of the leguminous plants. 



In the Mallee the prevailing characteristics are modified by two con- 

 ditions — the dryness of the climate and the extent to which the light sandy 

 soil drifts with the wind. On the better class of soil we find that the 

 concentration of plant food characteristic of dry regions is present. Con- 

 sequently the Mallee soils respond in a wonderful manner to every shower 

 of rain or application of irrigation water. The nitrogen is in a chemical 

 condition very readily available for plant food. The potash is nearly 

 always present in great abundance. Lime is also a prominent constituent 

 of the soil, in many cases running up to as much as from 10 to 25 per 

 cent, of the total weight of the soil. In the Mallee then the deficiency of 

 phosphoric acid is much more marked than in the hill country or even in 

 the greater part of the plain. Consequently the chief problem in the 

 Mallee is a, qtiestion of supplying phosphoric acid in easily available form 

 and of having the necessarv amount of moisture available. To put the 

 matter in a tabular form the results of average composition of these soils- 

 work out as under : — 



Such figures convey compaxativelv little information to a farmer, except 

 so far as they compare with the average of Victorian soi.s. Without 

 entering too much into theory, however, it ma\ be said that the surface 

 foot of an acre of land weighs approximately 2,000 short tons ; that 10 parts 

 of one O'f the constituent.s, sav phosphoric acid, to the loo.oco repre.sents a. 

 total v.eight of 400 lbs. per acre foot ; that when a farmer sows i cwt. of 

 superphosphate with his crop he adds approximately 20 lbs. weight of 

 phosphoric acid per acre or only .5 parts per hundred thousand. The 

 well known results of the addition of i cwt. of super, per acre indicate 

 the enormous influence of such a trifling amount upon the growth of the 

 plants, and it will therefore be seen that where our .soils contain from 

 50 to 100 parts of these constituents per 100,000 there is ample room for 

 extensive realization in this respect. To put the matter in another way, 

 20 tons of farm-yard manure to the acre means on the average an addition 

 of over 2 cwt. of nitrogen, t cwt. of phosphoric acid and 2 cwt. of potash 

 per acre. This amount means th.- addition of 6 i)arts nitrogen and potash 

 and 3 parts of phosphoric acid per hundred thousand. In other words 

 market garden land which has been steadily manured at the aloove rate for 

 20 vears has had a suflicient amount of plant food put into the surface 

 foot of the soil to completely change the poorest sand to rich agricultural 

 loam. 



