10 Aug., 1918.] Lucerne Manurial Trials. 497 



LUCERNE MANURIAL TRIALS AT RESEARCH FARM, 



WERRIBEE. 



THE VALUE OF WINTER TOP=DRESSING AND RENOVATION. 



(H. A. Mullett, B.Ag.Sc.) 

 Object of the Trials. 



Lucerne is a plant wliich has wonderful foraging powers. When 

 properly treated, yields from 6 to 8 tons of hay per annum may be 

 obtained. It, however, makes large demands on the soil minerals, and, 

 further, the watering which is usually neAessary is not without its effect 

 on fertility. 



On most soils continual application of water results in the surface 

 setting down. This leads to bad aeration and sour conditions, which, if 

 not treated, will inevitably depress yields. 



In extreme cases, such as may be seen in parts of the Goulburn 

 Valley, so great is the need for manures that many of- the stands are 

 now quite unprofitable, while often the continual watering and lack of 

 cultivation and drainage have caused such sour conditions, rushes have 

 come up during the last two years on farms where they have never been 

 seen before. It was with the object of determining the relative effect of 

 manures in supplying mineral deficiencies and in augmenting and arrest- 

 ing the decline of yields, that a series of top-dressing trials was laid 

 down at Werribee in 1913. 



Thorough winter renovation was adopted as standard practice, and 

 the success of both the manuring and the cultivation in maintaining 

 yields and the freedom from rushes has been strikingly demonstrated. 

 Similar results have been obtained in the northern irrigation districts. 



Lay=out of the Plots. 



The manures to be tested are top-dressed in parallel strips at right 

 angles to the direction of the greatest slope of the land; even watering 

 is therefore insured. The manurial application, which is top-dressed 

 after the winter renovation in August, is made only every second year. 

 Check plots, on which no manure is dressed are provided, and the dry- 

 cured hay from each is weighed separately. Up to six cuttings are 

 usually obtained per annum, but in some years, owing to failure of 

 irrigation supplies and to other causes, fewer cuts have resulted. Last 

 year four cuts were obtained, but, owing to shortage of labour, only three 

 of the four were weighed, so that the figures for the yields of 1917-18 

 are for these three cuts only. 



Results of Trials. 



From the very first it was evident that certain of the manures, par- 

 ticularly superphosphate and stable manure, were having a marked 

 effect on the yields. The effect of relatively insoluble manures like 

 Thomas' phosphate and bone fertilizer has not been marked. The use of 

 soil amendments like lime and ground limestone have given payable 



