258 



In regard to the injuriousness of spring fertilizing, reference should be 

 made to the reports of the General Assembly of the Society for the Advance- 

 ment of the Cultivation of Moors\ Here it is especially emphasized, that 

 kainit and Thomas slag must be scattered in the fall because spring fertiUz- 

 ing reduces the sugar and starch content in vegetables which require hoeing. 

 For Thomas slag, the fall fertilizing is said also to be more beneficial because 

 the acid of the moor can then act as a solvent for a longer time. Chili saltpetre 

 in cultural experiments had decreased the sugar content in edible roots about 

 1.5 per cent. The preceding crop also seems to have an influence on moor 

 cultures, as is shown by a case from the province of Posen-. There sugar 

 and late grown fodder beets became diseased when grown after mustard. In 

 regard to beet cultivation, Hollrung^ arrives at the conclusion that pure moor 

 land should be avoided entirely and even that which has been sanded should 

 be used only with care. 



Rotten Bark. 



Up to this point we have learned to recognize the characteristic starved 

 types of growth on acid moor soil ; these are due not only to the scarcity of 

 nutriment but to moisture conditions as well, either a lack of water 

 arising from the fluctuations in the subsoil, or an excess. These manifest 

 themselves in older trees by a greater formation of bark, when high cushions 

 of heather and moss surround the base of the trunk. These dense cushions 

 store up water, in part retaining that of the moor soil, in part collecting that 

 of the atmosphere, and in this way forming a moist felt constantly growing 

 up higher around the base of the trunk. Such damp cushions decrease the 

 temperature variations necessary for the pushing off of the old bark scales. 

 However, they hinder the supply of air especially and cause the decom- 

 position of those cell layers in the bark scales, which are especially loosely 

 constructed, into a deep brown mass, powdery in a dry condition and slimy 

 when very damp, which is called "rotted bark." In these are found the 

 brooding places of many animal and vegetable organisms which carry on 

 and hasten decomposition. 



An investigation of the younger layers under the old bark scales throws 

 light on the production of these rotted masses. One of the pieces of bark 

 furnished by Dr. Graebner from the Liineburger moor was 3.5 cm. thick and 

 differed from equally old, healthy bark in that it could be peeled with un- 

 usual ease into separate layers varying in thickness. The upper surface of 

 the different bark layers, as they fell apart, was rough like a relief map and 

 covered in places with hard, woody processes in the form of broad cones up 

 to 2.5 mm. high and often with crater-like depressions. Such processes, just 



1 Berichte der Generalversammlung des Vereins zur Forderung- der Moorkultur 

 Jahrg. 1895, p. 123. 



2 Elfter Jahresber. d. Sonderausschusses f. Pflanzenschutz. Arb. d. Deutsch. 

 Landw. Ges. Part 71, p. 130. 



3 Hollrung-, Die verschiedenen Bodenarten und ihre Eignung fiir den Riibenbau. 

 Blatter f. Zuckerrubenbau, 1905, No. 14, p. 217. 



