Technologies

Wetland system [Italy]

Aree umide in territori agrari

technologies_1647 - Italy

Completeness: 78%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:
SLM specialist:

Morari Francesco

University of Padova

Italy

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
University of Padova (UNIPD) - Italy

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Ja

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Vegetated water basins for the control of diffuse pollution

2.2 Detailed description of the Technology

Description:

In the last 50 years high intensive monoculture practices implied an oversimplification of agro-ecosystems, a decline of biodiversity and a deterioration in the quality of water resources. The need to prevent nonpoint surface water pollution form agricultural practices has recently led to consider wetlands as effective depurative systems. Construction and maintenance of wetlands have been supported by the Veneto region as an agri-environmental measure through the Rural Development Programme (RDP).

Purpose of the Technology: Wetland systems (WSs) depurate water resources from diffuse pollution, creating a semi-natural environment that promote wildlife and generally biodiversity. WS are characterised by the complete submersion (or for most part of the year) of the soil and a slow water flow that favour environmental and natural functions such as denitrification, flood control, suspended solids sedimentation. Moreover wetlands have been proposed as an alternative land use in reclaimed areas below the sea level which are facing problems of subsidence.

Establishment / maintenance activities and inputs: Thanks to their effectiveness on the improvement of agri-ecosystems, the maintenance and creation of wetland systems have been supported by the regional government in order to reduce the environmental impacts of conventional agriculture practices. The area invested to create a wetland depends on the input pollutants, the size of the area that is considered and the availability of space. The creation of a wetland system provides the establishment of emergent and submerged aquatic macrophytes on a water basin ca. 50 cm depth. The efficacy of water depuration is strictly related to the water residence time.

Natural / human environment: Adopting wetland systems allows to achieve several environmental benefits. Generally, the ecosystem is positively affected by the introduction of a water basin as it provides food, nesting cover and shaded areas to wildlife species. Sediment deposition, anaerobic denitrification conditions and the purifying effect of aquatic plants reduce eutrophication and improve the water quality. Due to their semi-natural structure and high differentiation of plant species, WSs enhance the quality of life through the improvement of agricultural landscape and the creation of recreational areas.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Italy

Region/ State/ Province:

Italy

Further specification of location:

Veneto region

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • 10-50 years ago

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • during experiments/ research

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • conserve ecosystem
  • protect a watershed/ downstream areas – in combination with other Technologies

3.2 Current land use type(s) where the Technology is applied

Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • cereals - maize
  • legumes and pulses - soya
  • wheat
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 210 Longest growing period from month to month: March to OctoberSecond longest growing period in days: 180

Waterways, waterbodies, wetlands

Waterways, waterbodies, wetlands

  • Swamps, wetlands
Comments:

Major land use problems (compiler’s opinion): Diffuse water pollution due to intensive agriculture
Future (final) land use (after implementation of SLM Technology): Other: Oo: Other: wastelands, deserts, glaciers, swamps, recreation areas, etc

3.3 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?
  • Yes (Please fill out the questions below with regard to the land use before implementation of the Technology)
Cropland

Cropland

  • Annual cropping

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • mixed rainfed-irrigated
Comments:

Water supply: rainfed, full irrigation

3.5 SLM group to which the Technology belongs

  • wetland protection/ management

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S11: Others
Comments:

Main measures: structural measures

Specification of other structural measures: Water basin

3.7 Main types of land degradation addressed by the Technology

biological degradation

biological degradation

  • Bh: loss of habitats
  • Bs: quality and species composition/ diversity decline
water degradation

water degradation

  • Hp: decline of surface water quality
Comments:

Main type of degradation addressed: Bh: loss of habitats, Bs: quality and species composition /diversity decline, Hp: decline of surface water quality

Main causes of degradation: soil management, population pressure

Secondary causes of degradation: crop management (annual, perennial, tree/shrub), deforestation / removal of natural vegetation (incl. forest fires)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • reduce land degradation
Comments:

Main goals: prevention of land degradation

Secondary goals: mitigation / reduction of land degradation

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Plan and longitudinal view of a constructed wetland sited at the Experimental Farm of University of Padova. A-B: longitudinal section; C: pump; D: wetland inlet; E: wetland outlet; F: side bank; G: stream.

Location: Legnaro. Padova, Italy

Technical knowledge required for field staff / advisors: high

Technical knowledge required for land users: moderate

Main technical functions: control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, improvement of water quality, buffering / filtering water

Dam/ pan/ pond
Height of bunds/banks/others (m): 0.3
Width of bunds/banks/others (m): 10
Length of bunds/banks/others (m): 40

Construction material (earth): Wetland banks are made locally by soil. Dimensions refer to 1 m3 water to treat/day

Author:

Passoni et al., 2009

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Euro €

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

0.8

Indicate average wage cost of hired labour per day:

21.00

4.3 Establishment activities

Activity Timing (season)
1. Capital costs for land, site investigation, plants, water control, media
2. Not available

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Other Capital costs. System implementation ha 1.0 2500.0 2500.0 30.0
Total costs for establishment of the Technology 2500.0
Total costs for establishment of the Technology in USD 3125.0

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • sub-humid

Thermal climate class: temperate

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
Landforms:
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • coarse/ light (sandy)
  • medium (loamy, silty)
Topsoil organic matter:
  • medium (1-3%)
  • low (<1%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility is low-medium
Soil drainage/infiltration is medium
Soil water storage capacity is medium

5.4 Water availability and quality

Ground water table:

on surface

Availability of surface water:

good

Water quality (untreated):

for agricultural use only (irrigation)

Comments and further specifications on water quality and quantity:

Water quality (untreated): For agricultural use only (surface water) and good drinking water (groundwater)

5.5 Biodiversity

Species diversity:
  • medium

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • commercial/ market
Off-farm income:
  • less than 10% of all income
Relative level of wealth:
  • average
  • rich
Individuals or groups:
  • individual/ household
Level of mechanization:
  • mechanized/ motorized
Indicate other relevant characteristics of the land users:

Population density: 200-500 persons/km2

Annual population growth: 0.5% - 1%

5.7 Average area of land used by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • medium-scale

5.8 Land ownership, land use rights, and water use rights

Land use rights:
  • individual

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased
Water availability and quality

irrigation water availability

decreased
increased

irrigation water quality

decreased
increased

Socio-cultural impacts

cultural opportunities

reduced
improved
Comments/ specify:

Increased awareness on biodiversity

recreational opportunities

reduced
improved
Comments/ specify:

Agro-tourism in improved natural areas

Improved livelihoods and human well-being

decreased
increased
Comments/ specify:

Improved agricultural landscape, biodiversity, agro-ecology and generally natural spaces, even for recreational activities. Moreover reduced water pollution.

Ecological impacts

Water cycle/ runoff

water quality

decreased
increased
Biodiversity: vegetation, animals

plant diversity

decreased
increased

beneficial species

decreased
increased

habitat diversity

decreased
increased

6.2 Off-site impacts the Technology has shown

water availability

decreased
increased

reliable and stable stream flows in dry season

reduced
increased

downstream siltation

increased
decreased

groundwater/ river pollution

increased
reduced

buffering/ filtering capacity

reduced
improved

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season increase or decrease How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
Climatological disasters
How does the Technology cope with it?
drought not well
Hydrological disasters
How does the Technology cope with it?
general (river) flood well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period well

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

negative

Long-term returns:

positive

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

neutral/ balanced

Long-term returns:

positive

Comments:

There is a need of initial investment, however wetlands can improve the multifunctionality of agricultural systems and create additional economic opportunities to the agro-ecological benefits.

6.5 Adoption of the Technology

Comments:

Comments on acceptance with external material support: The technology was supported by regional government and some farmers adopted it. However small farms (the majority in the area, just few hectares) can more difficulty adopt the technology due to a wide area required for its implementation.

Comments on spontaneous adoption: Very few adopted spontaneusly the technology

There is a little trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Improves surface water quality

How can they be sustained / enhanced? strenghten and support maintenance activity
Increases recreational areas

How can they be sustained / enhanced? Better territorial marketing
Favours biodiversity and faces the loss of habitats

How can they be sustained / enhanced? Enlarge wetland areas

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Reduces crop production Differentiate the farmers' income

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Treatment wetlands, Kadlec R.H & Wallace S.D., 2008

Title, author, year, ISBN:

Programma di sviluppo rurale per il veneto 2007-2013, Regione Veneto, 2007. Dipartimento Agricoltura e Sviluppo Rurale.

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