GENERAL CONDITIONS IN NEW ZEALAND 



53 



moisture in it from the previous season. Proof of 

 this is not wanting; for experiments tried in Australia, 

 at Rutherglen Viticultural College in Victoria afford 

 the following interesting results: 



TABLE XIII. 



Percentage of moisture on fallowed and non-fallowed land prior to 

 seeding, 1st May, 1912. Eutherglen Viticultural College, Victoria : 



Hence assuming the weight of 1 acre of dry soil to be 

 approximately 3,500,000 Ibs., it follows that in the first 

 4 feet of the Rutherglen fallow there were 571,200 Ibs. 

 more water per acre than in the non-fallowed land; i.e., 

 an amount equal to approximately 2J inches of rainfall. 



A second great advantage from fallowing arises from 

 the fact that it increases the supply of available plant 

 food. While the land is lying in fallow during the 

 summer months, many chemical and biological changes 

 take place within the body of the soil, and result in the 

 liberation of plant food. Experience proves that there 

 is a substantial increase in nitrates,* and there can be 

 little doubt that other important plant foods, particu- 

 larly potash and phosphoric acid, are converted from 

 unavailable to available forms. 



Thirdly, fallowing distributes the work on the farm 

 evenly throughout the year; for it enables the wheat 



*For example, at Longemong in Victoria, on fallowed land, 

 on 7th December, 1911, there was found to be 57-75 Ibs. of 

 nitrogen per acre present as nitrate in the first 5 feet. On 1st 

 April, 1912, this amount had increased to 105 Ibs. in the same 

 volume of soil. 



