1908.] 



Manuring of Forest Trees. 



745 



but also during seed time. Some similar conclusions in regard 

 to the flowering of fruit trees have been arrived at by Mr. E. P. 

 Sandsten, of the Wisconsin Agricultural Experiment Station 

 (Bulletin No. 137). He points out that the time of flowering 

 in the spring of a given variety of fruit is dependent upon a 

 number of causes or conditions, chief among them being, first, 

 the number of positive temperature units received in the spring 

 preparatory to flowering ; second, the stage of development 

 of the flower-buds as dependent upon the climatic conditions 

 of the summer and autumn preceding the flowering ; third, 

 the fruiting of the trees, whether light or heavy, the year previous 

 to flowering ; fourth, soil conditions and the amount of plant 

 food present in the soil ; and fifth, the individual charac- 

 teristics and state of health of the tree or plant. 



From the data given in the Bulletin, it would appear that 

 there is but little relationship between the time of flowering 

 and the temperature in the spring up to the time of flowering, 

 while there appears to be considerable evidence that the 

 temperature and other climatic conditions during summer and 

 autumn preceding flowering have much to do with the time of 

 flowering. 



The manuring of forest trees has been the subject of ex- 

 periment at the Prussian Forest Experiment Station at Ebers- 



walde, and elsewhere in Germany during 

 Manuring of Forest the past few years, and in the Mitteilungen 

 Trees. der Deutschen Land.-Gesell. (16th March, 



1907) Dr. Schwappach gives some account 

 of the various methods of manuring which have been tried. 

 From the experiments he concludes that the employment ol 

 nitrate of soda is of no value in nurseries of conifers on the 

 sandy soils of Germany, as it gets washed away before the young 

 plants are in a position to make use of it. These soils, moreover, 

 contain so much potash that the application of kainit is also 

 superfluous, while the phosphoric acid they contain is also 

 sufficient for pines. A decidedly favourable result was, how- 

 ever, obtained from nitrogen in a slowly acting form, such as 

 is provided by the cultivation of lupins. The growth of the 

 lupin is much stimulated by the use of kainit and basic slag. 

 The lupins are not now ploughed in, but allowed to die down. 



