International Journal of Agronomy

Research Article

Impact of Forage Fertilization with Urea and Composted Cattle Manure on Soil Fertility in Sandy Soils of South-Central Vietnam

Table 9

Treatment P values for the difference between postexperiment soil fertility parameters and preexperiment parameters in the 15 to 25 cm stratum. Each row represents a single model. Models include block as a random effect. Elemental analyses are for Mehlich-3 extractable elements. Significant effects (P ≤ 0.05) are in bold.


Parameter	Compost	Urea	Compost × urea

Total exchange capacity (cmol₊/kg)	0.9317	0.8727	0.8756
pH (1 : 1 soil : water)	0.0269	0.1749	0.0595
Organic matter (g/kg)	0.1604	0.0036	0.7973
S (mg/kg)	0.3240	0.4647	0.7185
P (mg/kg)	0.4661	0.2771	0.4179
Ca (mg/kg)	0.4523	0.8386	0.8740
Mg (mg/kg)	0.3694	0.0898	0.6977
K (mg/kg)	0.7658	0.4829	0.0413
Na (mg/kg)	0.2887	0.1182	0.4206
B (mg/kg)	0.2849	0.1422	0.5266
Fe (mg/kg)	0.3824	0.6983	0.1219
Mn (mg/kg)	0.2557	0.2068	0.4542
Cu (mg/kg)	0.1078	0.4458	0.1693
Zn (mg/kg)	0.7921	0.2485	0.0816
Al (mg/kg)	0.0189	0.2622	0.1371
NO₃-N (mg/kg)	0.4310	0.4914	0.1622
NH₄-N (mg/kg)	0.9296	0.3301	0.0985