172 



Manuring of Forest Trees. 



[JUNE, 



This is a point to which Pfeiffer attaches great importance, and 

 he recommends that plants should be selected for the green 

 crop the roots of which will penetrate the subsoil and prepare the 

 way for the roots of the young trees. By this means also the 

 subsoil moisture is made available, which in a dry year, such as 

 1904 was in Germany, is of great importance. The crop selected 

 for this purpose was peas. The soil was deeply cultivated 

 in autumn and left in a rough state ; in spring, about the end of 

 March, peas were sown broadcast on the undisturbed sod. 

 From the middle to the end of June the crop was ploughed 

 under, and shortly after mustard was sown in order to employ 

 the nitrogen from the peas. The mustard grew luxuriantly 

 and reached a height of four to six feet ; in autumn the mustard 

 was ploughed under, and its strong stalks served to keep the 

 soil open and expose it to the frost and weather. By this 

 system no other manure is necessary. The cultivation of crops 

 between the rows is not recommended, except perhaps on well 

 manured soil. After three or four years of green manuring, 

 strawberries might be planted and cropped for two years, and 

 then green manuring resumed ; or vegetables might be grown, 

 the same crop only recurring on the same plot every six or eight 

 years. The first crop of green manure, i.e., peas, can, if desired, 

 be used for fodder, as the roots will supply sufficient nourish- 

 ment to the mustard. 



Forest trees, after they have left the nursery, are not usually 



considered to require manure even in the early stages of their 



growth, and no special measures are taken 



Manuring" ^ 0 prepare the soil before transplanting, 

 of Forest Trees. „ r £. v . . , f , F ^ 



Within the last few years, however, the 



advisability of cultivating and manuring the soil before planting 



out has attracted attention in Belgium, Germany, and Holland, 



and, so far as experiments have gone, it may be concluded that 



a considerable increase in growth may be obtained by this 



means. A scheme* has been drawn up for a series of trials, to 



be conducted under the direction of the German Agricultural 



* Mitt, dentschen Land. GeseUschaft, 29 Apl., 1905. 



