Details
| Original language | English |
|---|---|
| Pages (from-to) | 155-164 |
| Number of pages | 10 |
| Journal | Journal of Plant Nutrition and Soil Science |
| Volume | 178 |
| Issue number | 1 |
| Publication status | Published - 1 Feb 2015 |
Abstract
Peat is commonly used as the main component of horticultural substrates, but it has a very low buffering capacity for the anionic macronutrient phosphorus (P), which can be increased by the addition of clays. The aim of this study was to characterize the P adsorption capacity of different substrate clays and to evaluate its significance for plant P uptake. Substrate clays were characterized with a single-point batch experiment and adsorption and desorption isotherms. The data were fitted to the Langmuir equation for a calculation of the maximum adsorption capacity. Additionally, the contents of oxalate extractable Fe and Al (ΣFeox + Alox) were determined. The influence of a varying P adsorption capacity of the clays on the P availability to plants in the respective peat-clay substrates and pure peat was investigated in a growth experiment with Impatiens walleriana fertigated with 0, 17, and 35 mgP L-1 solution, respectively. The observed and calculated (Langmuir) P adsorption capacity of the clays could be well-characterized by both the batch experiment and the adsorption isotherms and was highly correlated with the ΣFeox+Alox. A higher P adsorption capacity of the clay amendment in mixed substrates resulted in a lower P concentration in the substrate solution, while the CAT extractable P concentration (PCAT) was the same. Plant growth and shoot P concentrations were enhanced in the substrates, showing a higher P adsorption capacity, since plants were able to take up the whole amount of PCAT, and also part of the non-CAT extractable P. However, the release rate was too low to ensure optimal plant growth, which was in accordance with the result of the desorption experiment. The absolute extent of P release was increased with the increasing P adsorption capacity of the clays and higher degree of P saturation (DPS).
Keywords
- Batch experiment, CAT extraction, Degree of P saturation, Peat-clay blend, Phosphorus adsorption
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Soil Science
- Agricultural and Biological Sciences(all)
- Plant Science
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Journal of Plant Nutrition and Soil Science, Vol. 178, No. 1, 01.02.2015, p. 155-164.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Phosphorus buffering capacity of substrate clays and its significance for plant cultivation
AU - Binner, Inga
AU - Dultz, Stefan
AU - Schenk, Manfred K.
N1 - Publisher Copyright: © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copyright: Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/2/1
Y1 - 2015/2/1
N2 - Peat is commonly used as the main component of horticultural substrates, but it has a very low buffering capacity for the anionic macronutrient phosphorus (P), which can be increased by the addition of clays. The aim of this study was to characterize the P adsorption capacity of different substrate clays and to evaluate its significance for plant P uptake. Substrate clays were characterized with a single-point batch experiment and adsorption and desorption isotherms. The data were fitted to the Langmuir equation for a calculation of the maximum adsorption capacity. Additionally, the contents of oxalate extractable Fe and Al (ΣFeox + Alox) were determined. The influence of a varying P adsorption capacity of the clays on the P availability to plants in the respective peat-clay substrates and pure peat was investigated in a growth experiment with Impatiens walleriana fertigated with 0, 17, and 35 mgP L-1 solution, respectively. The observed and calculated (Langmuir) P adsorption capacity of the clays could be well-characterized by both the batch experiment and the adsorption isotherms and was highly correlated with the ΣFeox+Alox. A higher P adsorption capacity of the clay amendment in mixed substrates resulted in a lower P concentration in the substrate solution, while the CAT extractable P concentration (PCAT) was the same. Plant growth and shoot P concentrations were enhanced in the substrates, showing a higher P adsorption capacity, since plants were able to take up the whole amount of PCAT, and also part of the non-CAT extractable P. However, the release rate was too low to ensure optimal plant growth, which was in accordance with the result of the desorption experiment. The absolute extent of P release was increased with the increasing P adsorption capacity of the clays and higher degree of P saturation (DPS).
AB - Peat is commonly used as the main component of horticultural substrates, but it has a very low buffering capacity for the anionic macronutrient phosphorus (P), which can be increased by the addition of clays. The aim of this study was to characterize the P adsorption capacity of different substrate clays and to evaluate its significance for plant P uptake. Substrate clays were characterized with a single-point batch experiment and adsorption and desorption isotherms. The data were fitted to the Langmuir equation for a calculation of the maximum adsorption capacity. Additionally, the contents of oxalate extractable Fe and Al (ΣFeox + Alox) were determined. The influence of a varying P adsorption capacity of the clays on the P availability to plants in the respective peat-clay substrates and pure peat was investigated in a growth experiment with Impatiens walleriana fertigated with 0, 17, and 35 mgP L-1 solution, respectively. The observed and calculated (Langmuir) P adsorption capacity of the clays could be well-characterized by both the batch experiment and the adsorption isotherms and was highly correlated with the ΣFeox+Alox. A higher P adsorption capacity of the clay amendment in mixed substrates resulted in a lower P concentration in the substrate solution, while the CAT extractable P concentration (PCAT) was the same. Plant growth and shoot P concentrations were enhanced in the substrates, showing a higher P adsorption capacity, since plants were able to take up the whole amount of PCAT, and also part of the non-CAT extractable P. However, the release rate was too low to ensure optimal plant growth, which was in accordance with the result of the desorption experiment. The absolute extent of P release was increased with the increasing P adsorption capacity of the clays and higher degree of P saturation (DPS).
KW - Batch experiment
KW - CAT extraction
KW - Degree of P saturation
KW - Peat-clay blend
KW - Phosphorus adsorption
UR - http://www.scopus.com/inward/record.url?scp=84922212367&partnerID=8YFLogxK
U2 - 10.1002/jpln.201400523
DO - 10.1002/jpln.201400523
M3 - Article
AN - SCOPUS:84922212367
VL - 178
SP - 155
EP - 164
JO - Journal of Plant Nutrition and Soil Science
JF - Journal of Plant Nutrition and Soil Science
SN - 1436-8730
IS - 1
ER -