Wet Chemical and Phosphorus-31 Nuclear Magnetic Resonance Analysis of Phosphorus Speciation in a Sandy Soil Receiving Long-Term Fertilizer or Animal Manure Applications
G. F. Koopmans*,a,
W. J. Chardona,
J. Dolfinga,
O. Oenemaa,
P. van der Meerb and
W. H. van Riemsdijkc
a Alterra, Wageningen University and Research Centre (WUR), P.O. Box 47, 6700 AA, Wageningen, the Netherlands
b ATO, WUR, P.O. Box 17, 6700 AA, Wageningen, the Netherlands
c Department of Soil Quality, Wageningen University, WUR, P.O. Box 8005, 6700 EC, Wageningen, the Netherlands
View larger version (27K):
[in a new window]
|
Fig. 1. Inorganic and organic P for the different fertilizer regimes, measured in NaOH–Na2EDTA extracts by wet chemical analysis.
|
|
View larger version (13K):
[in a new window]
|
Fig. 2. Recovery of extracted organic P by NaOH–Na2EDTA relative to organic soil P plotted against the soil pH (KCl).
|
|
View larger version (25K):
[in a new window]
|
Fig. 3. Phosphorus-31 nuclear magnetic resonance (31P NMR) spectra of NaOH–Na2EDTA extracts from soils either amended with solid poultry manure mixed with litter (A) or amended with calf slurry (B). MDP denotes the P standard.
|
|
View larger version (24K):
[in a new window]
|
Fig. 4. Phosphorus-31 nuclear magnetic resonance (31P NMR) spectra of water extracts from soils either amended with poultry slurry (A) or amended with pig slurry (B). MDP denotes the P standard.
|
|
Copyright © 2003 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.
