Table 6. List of commonly used inorganic fertilizers used for mrigal culture and their calcium and NPK content
Type of fertilizer		Calcium	Nitrogen	Phosphorus	Potassium
CALCAREOUS
	Calcium carbonate (limestone)	40
	Calcium oxide (quicklime)	71.5
NITROGEN FERTILIZERS
	Sodium nitrate		16.5
	Ammonium sulphate		21.2
	Ammonium nitrate		35
	Urea		46.7
	Ammonium phosphate, dibasic		21.2	23.5
	Ammonium phosphate , monobasic		12.2	27
POTASSIUM (POTASH) FERTILIZERS
	Potassium chloride (murate of potash)				52.4
	Potassium nitrate		13.8		38.7
	Potassium sulphate				44.9
PHOSPHATE FERTILIZERS
	Di-calcium phosphate, anhydrous	29.5		22.8
	Bone meal	30		15
	Rock phosphate (fluoroapatite)	35		13
	Single superphosphate			7-8.7
	Triple superphosphate			19.2-23.6
Data source: Adapted from Tacon (1987)