702 Agncullural Gazette of N.S.JF. [Sept. 2, 1908. 



food and luoistui-c should lie aimed at. An applirat ion of sii]M'r])liospl)ate 

 ii)duces a vigorous stai't and uiaturcs tlie cioi) at)<)ut a. week eailicr t!iaii it' 

 iinmanured, two vci-y dcsiraliln effects under certain cunditions. Upon very 

 light sandy soils an application of potash may he desirable ; this should be 

 ascei'taincd by experiment. Sucli soils aie leachv in districts of heavy 

 rainfall and may respond to an application of -^nitrogenuu.s manures, such as 

 sulphate of ammonia or nitrate of soda. Mixed manures may be purchased 

 when the retjuirements of the .soil are ascMtaincd by experiment. 'The 

 majority of our wheat soils have suliicicnt clav in tlietn to be retentive of 

 potash and lutrates, and are content with phosphates alone, at any rate 

 for a time. Tlu' lack of response* when nitrogenous manures are userl is in 

 contradistinction to English recjuirements. Such is due to the light rainfall 

 not washing away a portion of the nitrates as they are formed from the soil. 

 Also that nitr-ates are formed practically throughout the year when the 

 winters are not severe and soil tempeiatures. dui'ing the heat of sunnner 



i 



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-r-mn 



Rape crop. 

 Battiursi Experiment Farm. 



reduced by cultivation and sutHcient moi;Uure consf-rved. The fact r^-mains 

 that, generally speaking, superphosphates increase the yields profitably, 

 whereas nitrogen and potash do not apprecial)ly increase returns. Tt is impos- 

 sible to state how long si/cli \n ill remain the case. Manures recpnre moisture 

 to render them available to p)lants. Conservation, of soil moisture by every 

 possible means sliould be carried out in conjunction with manuring. ^\ hen 

 a rotation of crops is followed in conjunction ^\ itli an occasional bare-fallow, 

 manuring presents very dilferent aspects than when wheat is grown 

 continuously upon the same land. 



Fal/oimni/. — In the driei' districts fallow ing is indispensable to successful 

 wheat-growing. By such, moisture is conserved and the i-ainfall of one 

 season carried over to supplempiit that of the next. Fallows are readily 

 ])ermeable by rains. The loose condition of the soil renrlers it a non-conductor 

 of heat ; soil temperatures are thereby kept lower throughout the heat of 

 summer. Australian soils get very hot in summer and the functions of the 

 valuable micro-organisms wliich libeiate plant food, itc, are suspended. Hot 

 soils dissipate moisture. It will thus be seen that fallowing, in keeping the 



