Soil carbon stocks and main nutrients under cocoa plantations of different ages

Figures & data

Table 1. Soil physical properties among different ages of cocoa plantation

Ages of cocoa plantation	Bulk density (g cm^−3)	Porosity (%)	Moisture (%)	Texture
				Sand (%)	Silt (%)	Clay (%)
5 years	1.38b	41.92b	14.97a	78.57a	8.00a	13.43a
10 years	1.38b	47.92a	20.03a	77.74a	8.67a	13.59a
14 years	1.31c	50.44a	21.56a	77.91a	8.67a	13.43a
18 years	1.53a	42.39b	18.60a	80.08a	6.93a	12.99a
23 years	1.29c	51.32a	18.60a	79.88a	7.73a	12.39a

Means in column followed by the same letters are not significantly different, P < 0.05.

Table 2. Soil chemical properties among different ages of cocoa plantation

Ages of cocoa plantation	pH (H2O)	SOC (%)	TN (%)	Available P (mg kg^−1)	Exchangeable
					K (cmolc kg^−1)	Ca (cmolc kg^−1)	Mg (cmolc kg^−1)
5 years	5.29a	0.71b	0.07b	9.1cd	0.19b	2.62a		1.11a
10 years	5.13a	0.73b	0.08b	7.4d	0.20b	2.91a		0.74a
14 years	4.98ab	0.80b	–*	9.9c	0.23a	3.22a		1.84a
18 years	4.58ab	0.83b	0.07b	12.8b	0.23a	1.79a		0.92a
23 years	4.86b	1.20a	0.11a	31.8a	0.24a	2.95a		1.38a
Critical level^#	5.6–7.2		0.09	20.0	0.25	7.50		1.33

Means in column followed by the same letters are not significantly different, P < 0.05.

*miss-measurement.

^#Critical levels were referred from Ahenkorah (1981) and Egbe, Ayodele, and Obatolu (1989).

Figure 1. Soil carbon stocks among different ages of cocoa plantations. Errors bars show the standard error. The same letters are not significantly different, P<0.05

Figure 2. Relationship between SCS and available P◯), and exchangeable K (☐) among different ages of cocoa plantations.

Ahenkorah, Y. 1981. “The Influence of Environment on Growth and Production of the Cacao Tree: Soils and Nutrition.” In Proceedings of the 7th International Cocoa Research Conference, 1979, 167–176. Douala, Cameroon.

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Egbe, N. E., E. A. Ayodele, and C. R. Obatolu. 1989. “Soils and Nutrition of Cacao, Coffee, Kola, Cashew and Tea.“ In: Progress in Tree Crop Research in Nigeria, 2nd Edition, 27–38. CRIN Ibadan.

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