Evaluation of Physicochemical Properties of Sandy-Textured Soils under Smallholder Agricultural Land Use Practices in Sarawak, East Malaysia

Table 6

Soil nutrient stocks in various agricultural land uses.

Soils (0–40 cm)^a	Total N (kg·ha^−1)	Available P (kg·ha^−1)	Exchangeable K (kg·ha^−1)	Exchangeable Mg (kg·ha^−1)	Exchangeable Ca (kg·ha^−1)
Secondary forest (SF)	3220	24	92	64	336
Oil palm land use (OP)	4671	58	71	56	300
Pepper land use (P)	4216	32	97	59	278

^aAverage values for all sites. Amounts of nutrients in soils were calculated as the sum of the value determined for 0–10 cm depth and three times the value determined for 30–40 cm depth. For the surface soils in oil palm farmlands and pepper farmlands, the average of the values determined for the centre point and fertilizing point samples was used.