13° 



Journal of Agriculture. 



[8 INIarch, 1907. 



and other carbon compounds, which they use as food. Probably most 

 of the carbonic acid, which forms one of the chief solvents in soil water, 

 has its origin in this way, and the chemical substances formed by bacteria 

 which are even more active, not only help to complete the weathering of 

 the rocks, but also to change the potash and phosphoric acid from insoluble 

 to soluble forms. 



All plant life is dependent on the water supply available in the soil. 

 How this may best be conserved and regulated is too large a question for 

 me to enter on at present. I would only remind vou that in order to 

 produce one ton of sun-dried \egetation from 300 to 500 tons of water 

 have to be absorbed bv the roots and transpired through the leaves. That 

 is, one ton of dried material per acre requires the utilization of the rainfall 

 to the extent of four or five inches during the growing season. 



Tht 



The Soils of Victoria. 

 following table gives the result of analysis of 178 samples of soil 



and sub.soil made within the last three vears at the laljoratory of the 

 Department. For comparison I append the average results of a number 

 of samples of ten different types of English soil (Hall), and of a very 

 large number of American analyses (HilLgard). It will be seen that 

 our soils are Avell al)Ove the recognised limits of efificiencv in nitrogen — 

 (100 parts per 1 00.000) — but verv close to the limit of inefficiencv as to 

 jihosphoric acid. European and American authorities look upon 50 

 parts per 100,000 as the limit below which it becomes unprofital)le tp work 

 the soil. Potash and lime are so abundant in most of our soils that thev 

 call for no remark: — 



AvRKAGE Results of Victorian, Exolish, and Amkricax Soil. 



Considering first the soils of Australia, I presume that so far as they 

 go, the results obtained from tie analvsis and experiment with those of 

 Victoria are fairly applicable to the rest of the continent. We have to 

 consider each of the three chief constituents — nitrogen. phosphoric acid, 

 and potash. So far as results of analysis are available, it appears that 

 on the a\erage our soils are as rich in nitrogen as those of Europe or 

 America, and nitrifying processes seem to go on with such rapidity that 

 for the most part, especially in dry areas, there is no need to add this 



