Effects of Biochar, Lime, and Compost Applications on Soil Physicochemical Properties and Yield of Pomelo (Citrus grandis Osbeck) in Alluvial Soil of the Mekong Delta

Table 3

Effects of soil amendments and years on subsoil properties (20–40 cm).

Factors		pH	SOM (%)	Ca^2+	K^+	Mg^2+	BD (g cm^−3)
				cmolc kg^−1
(A) Soil amendments	Control	4.45^b	3.04^d	3.37^b	0.94	4.05^b	1.19^b
	Biochar	5.56^a	3.89^b	4.72^a	0.88	5.02^a	1.01^a
	Lime	5.52^a	3.22^c	4.82^a	0.89	5.00^a	1.03^a
	Compost	5.62^a	4.12^a	4.71^a	0.93	5.10^a	1.01^a
(B) Years	2018	4.93^c	3.43^b	4.09^c	0.89	4.64^b	1.06
	2019	5.26^b	3.57^a	4.47^b	0.92	4.79^ab	1.07
	2020	5.68^a	3.70^a	4.72^a	0.93	4.94^a	1.04
F (A)					ns
F (B)					ns		ns
F (A × B)					ns		ns

Different letters in the same column indicate significant differences at , , and ; ns indicates no significant difference at . Control, NPK fertilizer; biochar, NPK fertilizer +5 ton·ha⁻¹·yr⁻¹ of biochar; lime, NPK fertilizer +2 ton·ha⁻¹·yr⁻¹ of lime; compost, NPK fertilizer +5 ton·ha⁻¹·yr⁻¹ of compost.