Phosphorus Speciation by ³¹P NMR Spectroscopy in Leaf Litters and Crop Residues from Para Rubber, Cocoa, Oil Palm, and Banana Plantations in the Humid Forest Zone of Cameroon

Table 4

The relative percentage of total extractable inorganic and organic P species in the NaOH-EDTA extracts based on total NMR peak area. Total P and total NaOH -EDTA-P concentration in mg kg⁻¹ and % recovery.

	Inorganic P			Organic P		Total P (HNO3) mg kg^−1	Total NaOH-EDTA-P mg kg^−1	Recovery %
Samples	Ortho-P	Pyro-P	Phytate	Other monoesters	Other diesters
	Relative percentage (%)
JN-01	89.2	5.8	-	5.0	-	1436.0	1113.4	77.5
JN-02	79.6	4.6	-	15.9	-	729.8	688.4	94.3
JN-03	72.5	3.1	-	24.4	-	1252.1	1112.9	88.9
JN-04	45.9	14.3	-	39.9	-	986.1	821.9	83.4
JN-05	54.3	-	-	34.3	11.4	1221.9	968.9	79.3
JN-06	81.4	4.8	-	13.8	-	1449.4	1260.8	87.0
JN-07	85.5	2.6	6.7	5.1	-	4001.2	4229.8	105.7
JN-08	53.0	5.7	-	41.3	-	865.2	618.9	71.5

Determined by Colorimetry [20].