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| Titel |
Nitrogen, phosphorus, potassium, calcium and magnesium release from two compressed fertilizers: column experiments |
| VerfasserIn |
M. J. Fernández-Sanjurjo, E. Alvarez-Rodríguez, A. Núñez-Delgado, M. L. Fernández-Marcos, A. Romar-Gasalla |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1869-9510
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| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 5, no. 2 ; Nr. 5, no. 2 (2014-12-21), S.1351-1360 |
| Datensatznummer |
250115362
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| Publikation (Nr.) |
 copernicus.org/se-5-1351-2014.pdf |
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| Zusammenfassung |
| The objective of this work was to study nutrients release from two
compressed nitrogen–potassium–phosphorous (NPK) fertilizers. In the
Lourizán Forest Center, tablet-type controlled-release fertilizers (CRF)
were prepared by compressing various mixtures of fertilizers without covers
or binders. We used soil columns (50 cm long and 7.3 cm inner diameter) that
were filled with soil from the surface layer (0–20 cm) of an A horizon
corresponding to a Cambic Umbrisol. Tablets of two slow-release NPK
fertilizers (11–18–11 or 8–8–16) were placed into the soil (within the first
3 cm), and then water was percolated through the columns in a
saturated regime for 80 days. Percolates were analyzed for N, P, K+,
Ca2+ and Mg2+. These elements were also determined in soil and
fertilizer tablets at the end of the trials. Nutrient concentrations were
high in the first leachates and reached a steady state when 1426 mm of water
had been
percolated, which is equivalent to approximately 1.5 years of rainfall in
this geographic area. In the whole trial, both tablets lost more than 80%
of their initial N, P and K contents. However, K+, Ca2+ and
Mg2+ were the most leached, whereas N and P were lost in leachates to a
lesser extent. Nutrient release was slower from the tablet with a composition
of
8–8–16 than from the 11–18–11 fertilizer. In view of that, the 8–8–16 tablet
can be considered more adequate for crops with a nutrient demand sustained
over time. At the end of the trial, the effects of these fertilizers on soil
chemical parameters were still evident, with a significant increase of pH,
available Ca2+, Mg2+, K+, P and effective cation exchange
capacity (eCEC) in the fertilized columns, as well as a significant decrease
in exchangeable Al3+, reaching values < 0.08 cmol (+) kg−1. |
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