548 THE farmers' handbook. 



The Life of a Stand. 



The time during which lucerne, once properly established, will continue 

 to yield payable crops will be found to vary with the nature of the soil and 

 subsoil, and the use to which the plants are put. On the best soils, such as the 

 deep, well-drained alluvial soils of the Hunter VaDey, the period for which 

 it will pay to crop lucerne before breaking up the ground is much longer 

 than on granitic uplands with an unfavourable subsoil or rock close to the 

 surface. Grazing any kind of stock on lucerne is much more injurious to 

 the life of the plants, owing to the consequent trampling, than removing the 

 cuttings for hay. While, therefore, it may be said that the average profit- 

 able life of a lucerne paddock is seven years, this estimate will be found to 

 be the mean between rather wide extremes. 



Lucerne gradually dies out, the termination of the life apparently being 

 due to the plants losing their vitality, as all plants do; but the termination 

 of its profit-yielding period is governed by other factors as well. The con- 

 tinuous growth of the one class of crop exhausts the fertility of the soil, 

 although lucerne, unlike clover, does not appear to cause land to become 

 " sick " in the ordinary sense of the term. After the land has been utilised 

 for other crops for a time, it can again be successfully laid down to lucerne. 



TOP-DRESSING WITH SUPERPHOSPHATE. 



There is a mistaken idea, prevalent among certain growers, that a lucerne 

 field requires no further attention than perhaps the usual cultivation given 

 early in the spring, and that it naturally increases in fertility. These 

 farmers argue that lucerne, being a legume, can gather nitrogen from the 

 air and enrich the soil; moreover, say they, its wonderful root system can 

 traverse a wide area in the soil in search of other necessary plant-foods. All 

 these things are undoubtedly true; but to be profitable, and to be continuously 

 so, lucerne requires attention as much as any other crop, and the farmer who 

 would lengthen the life of his stand and also derive from it the maximum 

 return while it is with him, will take care of it and neglect nothing that will 

 invigorate and maintain it. Lucerne removes much larger quantities of 

 other plant-food from the soil than most farm crops, and therefore depletes 

 the soil of these elements more quickly. 



The value of top-dressing lucerne with superphosphate as a means of 

 increasing the yield has been proved in quite a number of trials conducted by 

 the Department, first at Glen Innes Experiment Farm some years ago, and 

 more recently in several other parts of the State. 



On the Coast. — During the season 1919-20 a number of tests were made at 

 different centres in the central coastal district, viz., Mondrook, Pampoolah, 

 and Dungog. Amounts of 1 and 2 cwt. of superphosphate per acre were 

 used on the plots, and comparisons made with unmanured plots. Very 

 considerably increased yields resulted from the application of the super- 

 phosphate, the difference attributable to the top-dressing being as much as 

 8 tons from a total of four cuts in one instance. These increases in the 

 yields speak for themselves, but it was also observed at each centre 

 that the general condition of the stand was improved and that the crop was 

 of better quality. 



On the Tablelands. — In a trial conducted in 1916 and 1917 at Glen Innes 

 Experiment Farm, increased yields of 3 tons 17 cwt. and 6 tons 10 cwt. 

 resulted from applications of 1 cwt. and 2 cwt. per acre respectively of 

 superphosphate. Top-dressing now forms part of the regular farm practice. 



