Sept. . 19 rj. 



\\'//i'a/ and its Ciiliii'afioii. 



549 



Table 1. shows the amount of nitrates found in each of the first 

 5 feet of soil when fallowed, and when allowed to lie in pasture The 

 soil samples were taken in two ])arallel lines, the distance between the 

 fallowed and non-fallowed portions being 10 yards, whilst the distance 

 between each successive sampling was 5 yards. 



The nitrogen determinations were made by Mr. P. K. Scott, Cliemist 

 for Agriculture. 



In the above tallies, it will be ncjted that the anmunt of nitrate present 

 in each layer is continually changing. These changes follow closely on 

 the changes in the moisture content of the soil. With heavy showers, the 

 nitrates get washed down to lower depths. rndt-r hot dry siiells, they 

 tend to concentrate near the surface. 



The table clearly shows that, throughout the whole period during which 

 the investigations were made, the fallowed land contained far more nitrate 

 than the adjacent non-fallowed portion. If these tables are condensed, 

 and the figures reduced to pounds per acre, this point may hv more 

 ■clearly seen. 



Table II. — ^Total Nitrate Nitrogex in the first five feet of 

 Fallowed and Non-Fallow^ed Land under Ordinary Field 

 Conditions at Longerenong (Victoria), 1912. 



Date of Sampling. 



(1) 7th December, 1911 

 <-2) 4th January, 191-2 



(3) 6th February. 191-2 



(4) •28th March," 1912 



(5) 20th May, 1912 

 (<}) 7th August, 1912 



Amount of Nitrate Nitrogen. 

 (In Parts per Million.) 



Amount of Nitrogen. 

 (Reduced to lbs. per Acre.) 



* Now under crop. 



From this table it will be seen that the amount of nitrate in the 

 fallowed land gradually rose from 595 lbs. in December, to 118. 3 lbs. in 

 the first week in February, after which it gradually fell to 91-87 lbs. per 

 acre, as contrasted with 21 lbs. in the non-fallowed portion. As a 

 1 5-bushel wheat crop removes in its grain and straw about 21 lbs. of nitro- 

 gen (p. 203) per acre, it will be observed that there was four and a half 

 times more available nitrogen in the fallowed portion at seed time than was 

 required for a i5-f)ushel crop. 



On the other hand, in the non-fallowed portion there was barely enough 

 nitrogen to supply the requirements of one such crop even assuming that 

 e\ery particle of nitrate nitrogen in the first ^ feet could have been used 

 by thf croi). 



Moreover, at seed time, the nitrate nitrogen in the fallowed land 

 amounted to 71 lbs. per acre above that of the non-fallowed portion. 



If nitrate of soda containing 15 per cent, of nitrogen he worth 14s. 

 per cwt., then the cash value of this extra nitrate content of the fallowed 

 land over that of the uiifallowed portion anir>unted to no less than 

 jQ2 19s. 2d. per acre. 



