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| Titel |
Soil type as factor controlling the effects of forest transformation to agricultural use in soil aggregation and related properties |
| VerfasserIn |
Katarina Chrenková, Jorge Mataix-Solera, Pavel Dlapa, Victoria Arcenegui |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086211
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| Publikation (Nr.) |
 EGU/EGU2014-37.pdf |
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| Zusammenfassung |
| The stability of aggregates has an important role in soil functioning and its behavior to avoid
erosion and degradation, the ability to transfer liquids and gases, which are important features
for crop production and ecosystem health (Tisdall and Oades, 1982). It’s also a property that
is highly influenced by land use and management (Angers et al., 1993). The stability of
aggregates provides key information about the capacity of soil functions that defines the soil
quality.
This study has aimed to identify the long-term effects of forest transformation on
agricultural use on soil structure and related properties. For the research was chosen
seven localities in the Alicante Province (E Spain) with different soil types in all
cases to compare how the land use changes can affect as a function of soil type
and characteristics. In every site, samples were collected from agricultural land
use (dry crops with tillage management), and in forest areas close to them with
similar soil type that are used as references. On the samples, selected physical and
chemical properties were analyzed such as Soil aggregate stability (AS), Organic
matter (OM), Mean weight diameter (MWD) of aggregates and Water repellency
(WR).
As expected, in all cases the AS was significant lower in agricultural sites than in forest.
But in some cases the differences were much higher than in others. In forest sites the AS
varied between 46 to 82% while in agricultural sites ranged between 14 to 45%.
The results showed strong positive correlation of AS with OM. The lowest initial
values of AS were found in wettable sandy soils. The agricultural land use lead to
relative decrease in AS by 39 to 79% compared to forest soils, indicating that some
soils are much more vulnerable to land use than others. These differences can be
explained mainly because intrinsic soil properties, such as OM content, texture, and
WR. Particularly, the decrease in OM content and absence of WR are responsible
for the decrease in AS due to agricultural land use. Soil WR was found in three
of the sites, and its presence plays a key role in the aggregation and its stability,
especially in one of the sites with severe WR, since that type of soil is very sandy and
despite we expected initially a very low aggregation, the results showed 38 and
62% of AS for agricultural use and forest respectively, which is comparable to
other soils with high clay and carbonates content as stabilizing agents. The MWD
was in most cases higher in forest than in agricultural sites, except of two wettable
sandy soils with the lowest initial AS, where the MWD was higher in agricultural
sites.
As conclusions we can say that the use of tillage in agriculture affects aggregate stability,
but the magnitude is quite dependent of the soil organic matter, the texture and the presence
of WR. Some soils can be much more vulnerable than others to land use. In some cases the
presence of hydrophobic substances can play a key role in the formation and stabilization of
soil aggregates, contributing to maintain good levels of OM and avoiding higher levels of soil
degradation.
References:
Angers, D.A., N.Samson, and A.Légere. 1993. Early changes in water-stable aggregation
induced by rotation and tillage in a soil under barley production. Canadian J. Soil Sci. 73:
51-59.
Tisdall, J.M., Oades, J.M., 1982. Organic matter and water-stable aggregates in soils. J.
Soil Sci. 62, 141-163. |
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