=Nitrate of soda= supplies the single plant food-element, nitrogen, and the soda for all practical purposes may be disregarded.  It dissolves very easily in water and is taken up immediately by growing plants, its effect being plainly seen a few days after application.  As this artificial readily drains away from uncropped land it should only be administered to growing plants.  It is best applied in spring and summer and in small quantities; for example, at the rate of one pound per square rod, repeated at intervals of two or three weeks, rather than in a single large dose.  Nitrate of soda must not be mixed with superphosphate, but it may be added to basic slag and the potash manures.

=Sulphate of ammonia= is another nitrogenous fertiliser, similar in its effects to nitrate of soda, but slower in action since its nitrogen must undergo a change into nitrate before it is available for plants.  It is held by the soil, and can therefore be applied earlier in spring than nitrate of soda without fear of loss.  The continued use of this manure, however, is liable to make the soil sour, and consequently it should only be employed on ground containing lime, or to which lime has been added.  Never mix sulphate of ammonia with basic slag or with lime, but it may be mixed with superphosphate and the potash manures.

==Phosphatic manures== have the opposite effect to the nitrogenous fertilisers, checking rampant growth and encouraging the early formation of flowers, fruit, and seeds.  They are comparatively inexpensive and should be liberally applied to all soils for all crops. =Superphosphate= is an acid manure and best suited for use on soils containing lime. =Basic slag= is a better material for ground deficient in lime, or where ‘club-root’ is prevalent.  It is less soluble and therefore slower in action than superphosphate.  Both these fertilisers should be dug into the soil some time before the crop is planted or seed sown—­superphosphate at the rate of two to three pounds per square rod; basic slag in larger amount, five to six pounds per square rod.  Superphosphate may also be employed as a top-dressing and worked into the surface around growing plants with the hoe. =Steamed bone meal= or =flour= is another useful phosphatic fertiliser, valuable on the lighter classes of soil.

==Potash manures== are of benefit to plants in all stages of growth.  They are particularly valuable to Potatoes, leguminous crops, Carrots, Parsnips, Turnips, and Beet.  Like the phosphatic manures they should be worked into the soil before seeds are sown or plants are put out. =Kainit= is best applied in autumn, for it contains a considerable amount of common salt and magnesium compounds which are sometimes deleterious and best washed away in the drainage water during winter.  It should be dug in at the rate of about three pounds per square rod. =Sulphate of potash= is three or four times as rich in potash as kainit, and is correspondingly more expensive; apply in spring and summer, a little in advance of sowing or planting, at the rate of about one pound per square rod.