10 Feb., 1917. J Svieiicr and Prod net inn. 107 



falls in the winter months, whilst in Western Australia the winter rain 

 is as mucli as 85 per cent, of the whole. 



There are four factors which have assisted in pushing back this margin 

 of cultivation — 



(1) Improved cultivation methods, particularly the practice of fal- 



lowing, combined with thorough cultivation of the soil. 



(2) The use of superphosphate, wbich gives the young plant a start, 



encourages deep rooting, and makes the available soil mois- 

 ture more efficient. 



(3) The introduction of labour-saving implements, which get over 



a large area of ground in an efficient and economical way. 



(4) The use of varieties of wheat specially suited to arid districts. 



Fallowing is essential in these arid localities. The arnount of rain 

 in one year is not suflicient to grow a heavy crop ; but bj fallowing, 

 combined with careful working, one can make available the rainfall of 

 two winters for the use of the one crop. 



Experiments conducted at Longerenong, Rutherglen, and Werribee 

 show that it is possible by careful cultivation, to carry over from one 

 season to another at least 4 inches of conserved soil moisture in the first 

 '6 feet of soil. This quantity is sufficient, if it is all passed through the 

 plant, to grow an extra 10-12 bushels of wheat |>er acre. 



Superphosphate has been a most useful adjunct in these areas. .Sown 

 with the seed, it encourages deep rooting and rapid growing. It makes 

 the soil moisture more efficient by increasing the concentration of the 

 soil solution with respect to the most deficient plant food element, and, 

 therefore, lowering the transpiration ratio of the crop, i.e., the amount 

 of water required to elaborate 1 lb. of dry matter. 



Wheat for Arid Districts. 



The most important factor of all has been the growth of varieties 

 particularly suited to the drier districts. The ideal wheat would be that 

 variety which elaborated the greatest quantiy of grain per unit of water 

 consvimed. 



There seems to be very little difference in the transpiration ratio for 

 the different varieties of wheat as expressed in dry matter. An exami- 

 nation of six varieties in the pot culture house at Rutherglen last season 

 showed that to produce a ton of dry matter in Yandilla King variety 

 209 tons of water were required, whilst to produce the same quantity of 

 dry matter in Huguenot 243 tons of water were required. But when 

 we consider the quantities of water required to produce 1 ton of grain 

 we find remarkable differences, because the different varieties of wheat 

 differ very much in the amount of grain they produce, compared with 

 the dry matter. 



The ratio of the amount of grain produced compared with total straw 

 is called by Beaven the migration ratio. In a series of tests at Ruther- 

 glen it was found that Yandilla King was able to produce a ton of grain 

 for every 660 tons of water used, i.e., 6.4 inches of rain. Federation 

 required 750 tons, whilst Huguenot required 1,081 tons, and Kubanka 

 1,188. This is an interesting illustration of the efficiency of the two 

 varieties which are used in the drier districts of the State. 



