L'4<i THE FARMERS' BANKBOOK. 



Rotation on the Wheat Farm. 



Many of the problems that confront the wheat-grower may be solved by 

 rotation of crops. 



All farm crops require very much the same plant foods, but different crops 

 require them in different proportions. Hence, the production of the same 

 crop from the same land year after year tends to use up the supply of one or, 

 perhaps, two kinds of plant food faster than they are made available by the 

 ordinary processes that are going on in the soil, with the result that in a few 

 years the yields become consistently disappointing. The introduction, from 

 time to time, of a crop that uses different elements of plant food, or uses them 

 in different proportions, allows the renewal of the supply of that particular 

 element upon which the previous crop has made the heaviest demand, and 

 enables the farmer to return to his main crop with the assurance of greater 

 profit. 



The Value of Rotation. 



A change of crops, indeed, may sometimes actually result in an increase in 

 the supply of plant food in the soil. An illustration is afforded by the prac- 

 tice in parts of the tablelands of the State, where oats for hay and potatoes 

 are rotated. The cultivation required by the potatoes is quite different from 

 that required by the oats, and the effect of the different treatments is cer- 

 tainly to hasten the break-up of the chemical compounds in the soil, and thus 

 to render certain elements available that, though present previously, could 

 not be used by the plants. Another illustration may be quoted — that of 

 lucerne and wheat. Farmers know that no wheat-land yields grain like that 

 on which lucerne has been grown, and the reason is that the deep-rooting 

 habit of the lucerne has led to plant food being bi'ought from the subsoil and 

 made available for the surface-feeding wheat when the lucerne has been broken 

 up and the roots have decayed. 



Rotation has an important relation, also, to some of the active enemies of 

 crops — notably weeds, insects, and fungi. It is now widely recognised by 

 farmers that the occurrence of wild oats is closely associated with continuous- 

 cropping for wheat, and that some change is imperative if a dirty paddock is 

 to be cleaned up. Better illustration of this can hardly be furnished than by 

 the result of the "continuous wheat experiment" at Cowra Experiment 

 Farm. Certain land on that farm was cleared in 1906 and divided into 

 three main parts — one of these being devoted to wheat every year, another to 

 wheat alternated with fallow, and the third to wheat alternated with a fodder 

 crop. That experiment was initiated to prove that wheat cannot be grown 

 continuously without a serious loss in the eventual yields. And that was 

 exactly what happened. Seed of the cleanest and best quality was used \ 

 cultivation methods were adopted that should have tended to check and 

 destroy any oats that might have been on the land (an old common) ; but it 

 was to no purpose. Wild oats and Saucy Jack were to be seen by 1910, and 

 by 1912 they had so taken possession that the manager reported that " but 

 little wheat is now taken from the area, and the weeds have become a menace 

 to the cleared adjoining areas." It is a most significant fact that on the 

 sections where wheat was grown alternately with fallow and with fodder crops, 

 the oats were a negligible factor. A valuable experiment had thus to be 

 interrupted and started on a new area, simply because the "wheat-every-j ear" 

 portion had become infested with wild oats. The Department set out to 

 prove that continuous wheat is not profitable compared with some rotation, 



