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Phosphorus Status of a Soil Catena under Liberian Evergreen Rain Forest: Results of 31 P NMR Spectroscopy and Phosphorus Adsorption Experiments
Author(s) -
Forster Jürgen C.,
Zech Wolfgang
Publication year - 1993
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19931560110
Subject(s) - phosphorus , hectare , chemistry , nutrient , evergreen , fertilizer , adsorption , sorption , environmental chemistry , zoology , botany , ecology , biology , organic chemistry , agriculture
Phosphorus NMR spectra were recorded of the A horizons of a soil catena under vital stands of Liberian tropical high forest. Organic P compounds play a major part in the total P reserves (ca. 1/2 of total extractable P which is 1/5 of total soil P). Thereof, between 3.3 and 5.3 kg orthophosphate diester P per hectare participate in the plant available nutrient pool; similar amounts were calculated for the calcium acetate‐lactate soluble fraction. Persistent orthophosphate monoester P makes up an even greater percentage of soil P (10 to 25 kg ha −1 ). Mineral fertilizer requirements are in the range of 25 to 50 kg per hectare for 10 cm depth (based on a 48 hrs. adsorption experiment) when a soil solution concentration of 0.02 mg L −1 is considered adequate for the P supply of plants. P sorption can be explained by the amorphous fractions of Al and Fe hydroxides and the percentage of clay. The apparent vitality and absence of P deficiency symptoms of forest trees suggest the existence of an intact, however delicate, natural P cycle.