Research Article

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

Figure 3

Effects of treatments (T0, T1, T2, T3, and T4) and periods (30, 60, and 90 days) of incubation on soil exchangeable ammonium. Note. T0: 250 g soil (no urea); T1: 250 g soil + 7.40 g urea (no additives); T2: 250 g soil + 7.40 g urea + 6 g clinoptilolite zeolite; T3: 250 g soil + 7.40 g urea + 6 g compost; T4: 250 g soil + 7.40 g urea + 6 g compost + 6 g clinoptilolite zeolite. Means with the same letter are not significantly different by Tukey’s test at . Note. Letters without prime represent 30 DAI, single prime superscript represents 60 DAI, and double prime superscript represents 90 DAI.