18.5 



Scientific Agriculture. 



agriculture. It is an effective source of phosphoric acid for use upon all kinds of 

 soils, and on account of its high percentage of lime it is of special promise in the 

 reclamation not only of acid upland soils, particularly if rich in organic matter, 

 but also of marsh or muck soils. 



UXLEACHBD WOOD Ashes contain about 35 pounds of actual lime (calcium 

 oxid) in every hundred, 3 tons being, therefore, a little more than equivalent, in 

 lime, to 1 ton of burned lime. They also contain from 5 to 7 per cent of potash, 

 1 to 2 per cent, of phosphoric acid, and from 8 to 5 per cent, of magnesia. This 

 latter ingredient, though usually ignored, is of approximately as much value as 

 lime on acid soil. Soils are sometimes deficient in magnesia, and when this is the 

 case the magnesia applied in ashes has a direct manurial action. 



Leached wood ashes contain usually less than 1 per cent, of potash and 

 rather more lime than unleached ashes. Frequently they are sold in a wet condi. 

 tion, which of course lessens the quantity of actual lime present in a ton. 



Limekiln Ashes often contain approximately 40 per cent of lime, and when 

 wood is employed in the burning instead of coal they sometimes contain 2 per cent 

 or more of potash. 



Finely Ground Limestone and Oyster Shells can be used to advantage, 

 if obtainable, especially upon sandy soils. They are not as efficacious as after burn- 

 ing upon heavy clay soils, and such soils, as are very acid and contain large amounts 

 of sour humus. This is for the reason that they are not so active chemically, and 

 they cannot be reduced to so fine a state before burning as afterwards. 



Dye-house Lime usually contains only a small percentage of lime, and 

 if moist cannot be transported long distances at a profit. A rule that applies 

 well to this and all other waste products of a similar character is not to use 

 them until they have been subjected to chemical analysis, for by changes in the 

 processes of manufacture their value may be materially influenced and substances 

 injurious to A r egetatiou may have found access to them. 



Gas-house Lime. — It is never safe to use this substance until it has first 

 been allowed to weather for several months. On acid soils such lime is less 

 effective than burned lime, wood ashes, and limekiln ashes. Owing to recent 

 changes in the process of gas manufacture, lime is used less than formerly. 



Waste Lime from Beet-sugar Factories may be effectively applied to soils 

 after it has been allowed to dry. It contains some potash, phosphoric acid, 

 and nitrogen, which still further increase its value. If this material is applied 

 to the soil in a wet condition it tends to cake in the same manner as water- 

 slaked lime does when not immediately worked into the soil. It is sometimes 

 put in piles by itself and worked over every few weeks. It may also be dumped 

 in the field during the winter in small piles, where it is allowed to remain 

 until spring, when, after drying sufficiently, it may be spread and incorporated 

 with the soil. According to Heinrich, this material contains : Water 35 to 60 

 per cent ; nitrogen, 0.1 to 0.4 ; potash, 0.1 to 0.3 ; phosphoric acid, 0.5 to 1.5, and lime, 

 15 to 30 per cent. It is evident that this waste material in its moist condition could 

 not be transported to any considerable distance at a profit, and in this country, 

 where labor is such an important item, it would not pay to shovel it over much in 

 order to get it into condition to use. 



Waste Lime proai Soda ash Works usually contains considerable water, 

 and can for this reason only be employed to advantage where the cost of transport- 

 ation is small. If some economical means of drying it could be devised, the range of 

 distance to which it could be profitably shipped would be much increased. 



