|
1. Definition
| Name |
RECLAMATION
OF AFFECTED SOILS |
| Brief
definition |
According to UNCCD, the
main processes included in National Action Plans as leading
to desertification are soil erosion, acidification, salinization
and heavy metal contamination. Soils affected by acidification,
salinization or heavy metal contamination are considered here
as affected areas sensitive to desertification. Such areas
can be reclaimed by applying various techniques depending
on the degradation process.
 |
Plain
area with shallow ground brackish water table, desertified
due to salinization (photo by C. Kosmas) |
|
| Unit of measure |
None |
| Spatial scale |
|
| Temporal scale |
|
2. Position
within the logical framework DPSIR
| Type of Indicator |
Response |
3. Target and
political pertinence
| Objective |
Contribution
to the measures to combat desertification. |
| Importance
with respect to desertification |
Salinization,
acidification and chemical pollution are processes causing chemical
degradation of soils, adversely affecting the chemical environment
in the rootzone for the growing plants. The implications for
plant growth are often related to toxicities due to high concentration
of toxic elements such as aluminum, manganese, lead, chloride
or boron or to reduction in the availability of water by lowering
the osmotic potential. Under such conditions vegetation declines,
leading to desertification in coastal plain areas or other areas
with undisturbed soils from erosion or deposition of new soil
materials receiving large amounts of acidified fertilizers.
|
| International
Conventions and agreements |
There
exists a variety of legislations and regulations for conservation
of the natural environment and protection from degradation resulting
from human activities. |
| Secondary objectives
of the indicator |
Improving plant
growth, crop production and farmer's income and therefore favoring
application of management practices for combating desertification.
|
4. Methodological
description and basic definitions
| Definitions
and basic concepts |
The area of irrigated
land across the Mediterranean has substantially increased
in the last decades. However, extensive irrigation without
effective drainage practices in areas with high moisture deficits
may lead to soil salinization. Moreover, water consumption
has increased along with the increase in tourism and, combined
with the substantial increase in water requirements associated
with high input agriculture, brings about a significant water
allocation problem with further degradation of the plain areas
through salinization.
Soil acidification affects
a great portion of the area of cultivated land. Old alluvial
terraces or areas with soils formed on acid parent materials
show a rapid soil fertility degradation and productivity depression.
The use of heavy amount of ammonia-based fertilizers has resulted
in a rapid increase of soil acidity.
 |
Reclamation
of acidified soils by applying lime (Ca(OH)) (photo by
C. Kosmas) |
The reclamation of salt-affected
soils includes techniques such as: (i) construction of a channel
network and lowering the ground water table, and (ii) application
of excess of good water quality for leaching of soluble salts.
The reclamation of acidified soils is achieved by applying
lime in order to reduce soil acidity.
|
| Benchmarks
Indication of the values/ranges of value |
The applied management
practices for reclaiming such areas (if any) are rated as:
- adequate
- moderate
- low
- none
|
| Methods of
measurement |
This indicator
is assessed qualitatively subjected to personal judgment or
by measuring electrical conductivity of the soil, concentration
of available heavy metals, and soil pH. |
| Limits of the
indicator |
There are no
limits of the indicator.
|
| Linkages
with other indicators |
Aridity
index (1), Rainfall, Drainage,
Parent material, Infiltration
capacity, Fertilizer
application, Water quality,
Water availability, Flooding
frequency. |
5. Evaluation
of data needs and availability
| Data required
to calculate the indicator |
Land management
practices for soils subjected to chemical degradation. |
| Data sources |
Necessary data
are usually available and accessible. |
| Availability
of data from national and international sources |
Data
can be obtained from national agencies, various regional institutions
involved in collecting and elaborating data on natural resources
management. |
6. Institutions
that have participated in developing the indicator
| Main institutions
responsible |
Agricultural
University of Athens. |
| Other contributing
organizations |
Universities
of Lisbon, Murcia and Basilicata.
|
7. Additional
information
| Bibliography
|
Lai,
R., Blum, W.H., Valentine, C., and Stewart, B.A. 1998. Methods
for assessement of soil degradation. CRC Press, New York, 558
p. |
| Other references |
Rowell D.L. 1995. Soil
Science, Methods & Applications. Longman Scientific &
Technical, Longam Group Limited, England, 350 p.
Conacher, A., and Sala,
M., 1998. Land Degradation in the Mediterranean Environments
of the World: Nature and Extent, Causes and Solutions. J.
Wiley & Sons, Chichester, 491 p.
|
| Contacts Name
and address |
Dr. C. Kosmas
Agricultural University
of Athens, Laboratory of Soils and Agricultural Chemistry,
Iera Odos 75, Athens 11855, Greece
email: lsos2kok@aua.gr
|
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