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phosphatic manures are compounds of phosphoric acid with lime. 

 Only one, superphosphate, is freely soluble in water, and the value 

 and price of phosphatic manures depend on the amount of soluble 

 phosphates they contain. 



Superphosphate was the first to be discovered. It is usually 

 guaranteed to contain 26 per cent, soluble phosphate, emd is sold at 

 about £5 to £6 a ton. It is best to apply it early in the spring, and 

 a dressing of 8 cwt. an acre, or 8 lb. to forty square yards is 

 quite enough. Care must be taken in spreading it, as it bums the 

 leaves if a large deposit falls on them. Superphosphate is especially 

 valuable not only in helping the fruit to mature, but also in stimu- 

 lating the root-action of young plants. It is the most effective of 

 the phosphatic manures on most soils, except very sandy soils deficient 

 in lime, and all acid soils. The presence of plenty of hme to ensure 

 the precipitation of the soluble phosphoric acid should determine its 

 choice. On most heavy clays basic slag is better, at about half the 

 price of superphosphate, and is nearly as effective, when it is appUed 

 in early winter and has had time to saturate the soil water. Thus the 

 choice between the two should be determined by the amount of lime 

 in the soil, superphosphate being suitable for chalky and loamy soils, 

 and basic slag for heavy soil, and soils deficient in lime, as it pro\ades 

 lime. For very Ught sandy soils a good mixture may be made as 

 follows : — ^Two parts of superphosphate, with one of steamed bone 

 flour or bone meal. Leave the heap for a time and break up thoroughly 

 when caked. For sandy soils use " Super," as basic slag is not much 

 use on them. 



Phosphate of potash is very soluble in water, and a valuable though 

 costly fertihzer, the price being £40 a ton. A very effective hquid 

 manure for such greenhouse plants as tomatos is made by dissolving 

 J to ^ oz. of it to a gallon of water. 



Phosphate oj ammonia is also dear, but makes a good stimulant, 

 i to I oz. of it to one gallon of water being a satisfactory hquid manure 

 for greenhouse purposes. The price is about £50 a ton. 



Insoluble phosphates are very slow in action, as mentioned before, 

 and should only be used when a reserve is needed for plants to 

 draw upon gradually. Steamed bone flour is the best form, costing 

 £10 to £12 a ton, and is very useful to mix in a fruit border under 

 glass. 



Bones and phosphatic guanos should be avoided, unless obtainable 

 at very low prices. 



Potassic Manures. — ^These are chiefly valuable on Ught sandy 

 soils, especially for starch and sugar-producing crops, such as roots 

 and fruits, and also for leguminous crops, peas, beans, &c. Moreover, 

 fungoid diseases are less deadly to plants well suppHed with potash 

 than to those that are not. Plants benefit most in dry seasons from 

 potcissic maniures, as they tend to delay maturity of the fruit until 

 growth is completed. Wet clay soils do not seem to benefit by it 

 much, as it increases their stickiness. In fact potassic fertihzers need 



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