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| Titel |
Identifying soil management zones in a sugarcane field using proximal sensed electromagnetic induction and gamma-ray spectrometry data |
| VerfasserIn |
Claire Dennerley, Jingyi Huang, Rod Nielson, Michael Sefton, John Triantafilis |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138604
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| Publikation (Nr.) |
 EGU/EGU2017-1672.pdf |
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| Zusammenfassung |
| Over 70% of the Australian sugarcane industry operates in alluvial-estuarine areas
characterised by sodic and infertile soils. There is a need to supply ameliorants and improve
fertilisers and minimise off-farm pollution to the Great Barrier Reef. Therefore, information
is required about the spatial variation in soils. However, traditional approaches are
cost-prohibitive. Herein we showed how a digital soil mapping (DSM) approach can be used
to identify soil management zones. In the first instance, ancillary data, including
electromagnetic induction and gamma-ray spectrometry data were collected. Using a fuzzy
k-means clustering algorithm management zones from two to six were identified. Using
restricted maximum likelihood (REML) analysis of various topsoil (0–0.3m) and subsoil
(0.6–0.9m) physical (e.g. clay) and chemical (e.g. exchangeable sodium percentage [ESP],
exchangeable calcium and magnesium) properties, 3 zones were determined from
minimising the mean squared prediction error. To manage the moderately sodic
topsoil ESP of zones 3A and 3C and sodic 3B, different gypsum requirements were
prescribed. Lime can also be added differentially to address low exchangeable Ca
in zone 3A, 3B and 3C. With regard to exchangeable Mg, zones 3A and 3C do
not require any fertiliser, whereas zone 3A requires the addition of a moderate
amount. The results were consistent with percentage yield variance, suggesting the
lower yield in 3C due to topsoil sodicity and strongly sodic subsoil with higher clay
content. We concluded that the DSM approach was successful in identifying soil
management zones and can be used to improve structural stability and soil fertility. |
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