Improving Ammonium and Nitrate Release from Urea Using Clinoptilolite Zeolite and Compost Produced from Agricultural Wastes

Table 2

Selected chemical properties of clinoptilolite zeolite.

Property	Present study	Reference
	(mean ± SE)
pH	6.80 (±0.03)	8-9
CEC (cmolc kg^−1)	100.33 (±0.35)	160
Total nitrogen (%)	1.18 (±0.04)	1.36
Calcium (mg kg^−1)	18,400 (±19.09)	25,600
Magnesium (mg kg^−1)	11,200 (±4.48)	15,000
Potassium (mg kg^−1)	14,850 (±10.17)	22,600
Ammonium (mg kg^−1)	12.60 (±0.43)	nd
Nitrate (mg kg^−1)	11.58 (±0.18)	nd

Note. CEC = cation exchange capacity, nd = not determined. Data were obtained from Luxurious Empire Sdn. Bhd., Kulaijaya, Malaysia. Values in parenthesis represent standard error of the mean.