794 JOUKNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Belgium seems to be in advance of all other countries in the use of 

 large quantities of fertilisers for forests. Sixteen to 18 inches is the 

 usual depth of ploughing there before planting, and if a subsoil plough 

 can be used 2 feet 4 inches to 2 feet 6 inches is not unusual. Large tracts 

 of waste lands are thus planted and fertilised, and to do so at the smallest 

 expense Eye and other crops are raised for some years between the rows 

 of the young trees. Green manuring mostly consists of Lupines, which 

 will penetrate even hard and pebbly soils to a depth of 3 feet, and thus 

 permit the moisture to rise, by means of the openings left by their dead 

 roots, for the benefit of the trees. Liming is also used, or in very sandy 

 soil marling is preferable. Potash and phosphoric acid are added to 

 improve the surface soil, which, when thus treated, is expected to keep 

 the trees in good health and growth for ten to fifteen years, after which 

 time the roots are likely to find sufficient nourishment in the deeper sub- 

 soil. Where green manuring with Peas was used on a sandy soil of the 

 eighth class, a good crop gave no less than 180 lb. of nitrogen per acre, 

 equal to about 1,150 lb. of nitrate of soda. Prof. Dr. Goetting used in 

 one instance 640 lb. of Thomas phosphate and also of kainit ; in another 

 twice as much ; and Dr. Dalgas, of the Association for Planting Danish 

 Heath-lands, actually recommends five to ten times as much potash, and 

 four to six times as much phosphoric acid. 



That it will pay to use fertilisers for forests can hardly be doubted. 

 The experiments, at least, are very encouraging, but more time must 

 elapse to decide whether any further fertilisers are required, whenever, for 

 instance, Pines show at a certain age a stoppage in their growth. Prof. 

 Dr. Wohltmann, after many experiments, declares that in most instances 

 large stores of mineral fertilisers are to be found in the deeper subsoils, 

 and thinks more manuring unnecessary. It is ascertained that 1 lb. of 

 nitrogen is sufficient to produce from 125 to 200 lb. of dry wood, 1 lb. of 

 potash up to 3,300 lb., and 1 lb. of phosphoric acid up to 5,000 lb. 

 Whenever fertilisers are given to single seedlings or to larger trees, 

 they should not be used in larger quantities, nor without being well 

 mixed with the soil. From 1 to 2 oz. of Thomas phosphate, ^ to 1 oz. of 

 40 per cent, kainit, and ^ to ^ oz. of nitrate of soda may be sufficient, the 

 last to be repeated the following year. In Eberswalde, in a forest of 

 seventy-year-old Pines in poor condition, 800 lb. of both Thomas phos- 

 phate and kainit and 160 lb. nitrate of soda per acre were used. At 

 Hadamar, Oaks eighty years old have been felled, and Pines sown amongst 

 the stumps wdth the same quantity of fertihsers. The stumps showed 

 shoots as much as 6 feet long, while on unmanured land these were only 

 2 to 3 feet long. Fifteen-year-old Pines in miserable condition, only 

 1 foot 8 inches high, and making only 2-indi shoots annually, were three 

 years ago mulched with horse-dung. In the very first year they showed 

 a fine green colour, and the average annual shoots made since are more 

 than a foot long. Mulching with potato haulm or other material gave not 

 quite so good a result. The annual shoots averaged 8 inches ; the 

 nourishing constituents in the dung caused, therefore, the growth of the 

 extra 4 inches. 



