49° Journal of Agriculture, Victoria. [lo July, 191 i. 



through the application of ammonium salts. Also, on the limed plots, 

 where peat had accumulated, the effect was a close sward of grass and the 

 disappearance of the peat. 



Nitrogetious fertilizers. — New nitrogenous fertilizers were further experi- 

 mented with, the results, however, bemg disappointing. Nitrate of lime 

 and cyanide gave poor returns, while nitrate of soda was the most 

 effective source of nitrogen applied. 



Nitrate supplies. — The conclusion adopted was that, under field con- 

 ditions, the factor limiting the formation of nitrates is really the preliminary 

 ammonia-producing process, and instead of the rate of nitrification, it is 

 the rate of ammonia production which determines the amount of nitrogen 

 available for the crop. 



Dressings of farmyard manure gave better returns than any of the 

 artificial fertilizers. 



Rotation cropping. — An experiment in connexion with rotation cropping 

 gave most useful information in regard to the preparation of the soil for 

 wheat, and bears special significance to soils that require building up in 

 humus and nitrogen. After the growth of \'etches the yield of wheat was 

 best, and after leguminous crops generally, such as crimson clover and 

 vetches, was 60 per cent, better than after rape or mustard. It was also 

 noticeable that on all the plots following green manuring, there was an 

 absence of the blight which characterized the wheat elsewhere. 



The yield of straw was even more favourable than the grain, after 

 clover and vetches, and was due, in all probability, to the storage of 

 nitrogen in the soil by these crops and the supply of humus in the shape 

 of decomposing roots, &c., This knowledge should be especially useful to 

 Victorian farmers in showing how humus and nitrogen can be supplied in 

 our soils as a partial substitute for farm manure which cannot be secured 

 in sufficient quantities in this country for our wheat areas. 



The accompanying table gives the actual returns: — 



Green Crop. 



Mustard 



Rape 



Crini.son Clover 



Vetches 



Other experiments such as " Clover sickness " and " The effects of 

 heating and of antiseptics on the fertility of the soil " have been continued 

 but have not yet reached the stage for report. 



