ASHES WHICH ARE BENEFICIAL TO SOIL

Evening Star, Issue 22596, 13 March 1937, Page 24

ASHES WHICH ARE BENEFICIAL TO SOIL

Ashes are the waste products left from burning various refuse, such as clippings, wood, and other vegetable matter. These contain mineral matters, and vary in richness according to the material from which they are derived. Wood ashes are the material which is left when wood is burnt, and the quantity of ash varies according to the vegetable matter from which it is produced. Leaves, we are told, in 100 parts of dry matter give 15 per cent, ash, sapwood in 100 parts of dry matter give 3 per cent, ash, bark in 100 parts of dry matter give 7 per cent. ash. But the more from herbaceous plants the higher is the proportion of ash. The ash also varies considerably from the different species of wood burnt. Birch is poor in ash, containing only 10 per cent, potash. Oak a little higher. Poplar is very rich in potash, as rich as kainit (12 x 13 per cent.), and also contains a large percentage of phosphoric acid; but pine, which is very common in New Zealand, contains only about 10 per cent, of potash. It is also very poor in phosphoric acid, containing only about 4 per cent. Wood ashes form an excellent potassic manure for peas and beans and similar crops. The ashes should never be allowed to be exposed to the air, and should be protected from rains, so as to preserve the potash. Peat ashes are very beneficial for the dressing of lawns, as they contain sulphate of lime. To obtain the ash peat should bo allowed to dry and then placed into stacks., and then -it can be burnt verv slowly. In _ Holland, for hulb growing, it is used in large quantities. In the low-lying districts in and around Dunedin large quantities of peat are to be found under the sand and top soil. Coal ashes can be tised for improving heavy soils, especially where stiff clay is present. The whole can be made more workable. Coal ashes contain lime and also sulphuric acid, magnesia, and phosphoric acid. If the ashes are mixed with garden soil they make it earlier because of their black colour.

Furze and Bracken.—The ashes of these are rich in potash, containing about 30 per cent., also a small quantity of phosphoric acid; but where the plants are young it is more beneficial to turn them into the ground than burning. ■ ■ . Soot is one of the most valuable of the ashes we have for vegetable growing. It should he used freely in the gardens, as with coal ashes. Its, black colour tends to make soil earlier. Soot contains potash and sulphuric acid, from which sulphate of ammonia is formed, also a percentage of nitrogen. Where soot is used freely the vegetables contain a much higher flavour, and, what is most important, it keeps under many plant diseases. F.S.P.