It appears that with soils which are not rich in humus or not deficient in lime, calcium cyanamide is almost as good, nitrogen for nitrogen, as ammonium sulphate or sodium nitrate; but it is of doubtful value with peaty soils or soils containing little lime, nor is it usefully available as a top-dressing or for storing.
It has been found by experiment that the nitrogen needed by practically all farm crops except leguminous ones is best supplied in the form of a nitrate; the rapid effect of nitrate of soda when used' as a top dressing to wheat or other plants is well known to farmers..
The plant grows freely in good garden soil, preferring a deep welldrained loam, and is all the better for a top-dressing of manure as it approaches the flowering stage.
Malt-dust is an active manure frequently used as a top-dressing, especially for fruit trees in pots.
Gypsum, or sulphate of lime, applied as a top-dressing at the rate of 2 to 3 cwt.
