Technologies

Straw mulching to improve soil quality [Spain]

Efecto de la cubierta de paja en la calidad del suelo (spanish)

technologies_1255 - Spain

Completeness: 84%

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:
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Universidad de Valencia (Universidad de Valencia) - Spain

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

28/05/2015

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

Ja

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

Nee

Comments:

It is a good way to restore land

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Straw mulch application on bare soil in order to prevent soil erosion, reduce overland flow, and increase soil organic matter.

2.2 Detailed description of the Technology

Description:

In a persimmon crop area near Valencia (South-East Spain), the research team of the University of Valencia has set up an experiment in 2015 to test the effect of the straw mulch technique in order to avoid water erosion and improve soil properties. Straw mulch was applied at a rate of 75 g per m2 and spread over 40 erosion plots (20 treated/20 non-treated). Afterwards, rainfall simulations at 78 mm h-1 of I30 mimic a high-magnitude storm.
The straw provides an initial cover of 60%, and was found to reduce runoff from 60% (in non-treated plots) to 29% (in treated plots), and erosion from 5.1 Mg ha-1 to 0.2 Mg ha-1.

Purpose of the Technology: The increase in ground cover will decrease soil erosion by reducing raindrop impact over the bare soil. Runoff also decreases by increasing water surface storage, decrease of runoff velocity, and increase infiltration.
Its application must to be done before high-storm events in the Mediterranean; namely end of summer to early autumn, in order to protect raindrop impact and avoid detachment of bare soil.

Establishment / maintenance activities and inputs: The straw mulch was delivered from a nearby farm in straw bales and was manually applied to the research plots.

Natural / human environment: The wine production in the area was implemented by old civilizations. Nowadays, vineyards production is spread over the entire study area, together with new plantations of persimmon, apricots, olives and oranges. The landscape reflects the long history of management where several constructions related with wine production depicted its importance on this region. Since the late 1960s, conventional agriculture with fertilizers and herbicides has led to a seasonally bare soil surface, triggering huge erosion rates.

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:

Spain

Region/ State/ Province:

Spain

Further specification of location:

Valencia district

Comments:

Specify the spread of the Technology:
evenly spread over an area

If the Technology is evenly spread over an area, indicate approximate area covered:
< 0.1 km2 (10 ha)

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • during experiments/ research
  • through projects/ external interventions

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation

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

Forest/ woodlands

Forest/ woodlands

Products and services:
  • Fruits and nuts
  • Other forest products
  • grapes, persimmon, apricots, olives and oranges
Unproductive land

Unproductive land

Specify:

shrub vegetation: quercus ilex, quercus coccifera, pistacia lentiscus, rosmarinus officinalis; Grass species: brachypodium retusum

Comments:

Major land use problems (compiler’s opinion): Increased runoff and soil erosion, resulting in a decrease of on-site fertility, water reservoir, and weakness of hydrological soil properties.
Major land use problems (land users’ perception): Loss of water-soil resources and productivity.

If land use has changed due to the implementation of the Technology, indicate land use before implementation of the Technology:

The landscape reflects the long history of management where several constructions related with wine production depicted its importance on this region. Since the late 1960s, conventional agriculture with fertilizers and herbicides has led to a seasonally bare soil surface, triggering huge erosion rates.

Change of land use practices / intensity level: yes, change due to diminish herbicides application, and minimize bare soil exposition.

3.3 Further information about land use

Water supply for the land on which the Technology is applied:
  • rainfed
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 180, Longest growing period from month to month: February to July

3.4 SLM group to which the Technology belongs

  • improved ground/ vegetation cover

3.5 Spread of the Technology

Specify the spread of the Technology:
  • evenly spread over an area
If the Technology is evenly spread over an area, indicate approximate area covered:
  • < 0.1 km2 (10 ha)

3.6 SLM measures comprising the Technology

agronomic measures

agronomic measures

  • A1: Vegetation/ soil cover
vegetative measures

vegetative measures

  • V1: Tree and shrub cover
management measures

management measures

  • M2: Change of management/ intensity level
Comments:

Type of agronomic measures: mulching

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
physical soil deterioration

physical soil deterioration

  • Pk: slaking and crusting
biological degradation

biological degradation

  • Bc: reduction of vegetation cover
water degradation

water degradation

Comments:

Causes of degradation: soil management, crop management (annual, perennial, tree/shrub), over-exploitation of vegetation for domestic use, disturbance of water cycle (infiltration / runoff), Heavy / extreme rainfall (intensity/amounts)

3.8 Prevention, reduction, or restoration of land degradation

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

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

4.1 Technical drawing of the Technology

Author:

Artemio Cerdà, University of Valencia. Dept. geography

4.2 Technical specifications/ explanations of technical drawing

Straw mulch must be spread homogeneously in bare soil areas between trees lines in order to keep as much as possible the soil covered.

Location: Canals. Valencia, Spain

Technical knowledge required for field staff / advisors: low (It is easy to implement)
Technical knowledge required for land users: low

Secondary technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, improvement of ground cover, increase of surface roughness, improvement of topsoil structure (compaction), increase in organic matter, increase in nutrient availability (supply, recycling,…), increase of infiltration, increase / maintain water stored in soil, improvement of water quality, buffering / filtering water, sediment retention / trapping, sediment harvesting, increase of biomass (quantity), promotion of vegetation species and varieties (quality, eg palatable fodder)

Mulching
Material/ species: SPRING BARLEY
Quantity/ density: 75g/m2

Slope (which determines the spacing indicated above): 2%
Change of land use practices / intensity level: yes, change due to diminish herbicides application, and minimize bare soil exposition.

4.3 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:
  • per Technology unit
Specify unit:

ha

Specify currency used for cost calculations:
  • US Dollars
Indicate exchange rate from USD to local currency (if relevant): 1 USD =:

800.0

Indicate average wage cost of hired labour per day:

80

4.4 Establishment activities

Activity Type of measure Timing
1. Apply straw mulch (75g/m) Agronomic summer

4.5 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Straw Kg 1000.0 100.0

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The price of straw varies, depending on the quality. Transport and application will increase the cost.

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
Specifications/ comments on rainfall:

Dry spells of 3 months (june, august, september)
Other rainfall annual averages are 250-500mm (ranked 2) or >250mm or 750-1000 mm (both ranked 3)

Agro-climatic zone
  • sub-humid
  • semi-arid

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.
Indicate if the Technology is specifically applied in:
  • not relevant

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):
  • medium (loamy, silty)
Topsoil organic matter:
  • medium (1-3%)
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 medium
Soil drainage/infiltration is medium
Soil water storage capacity is medium

5.4 Water availability and quality

Ground water table:

5-50 m

Water quality (untreated):

for agricultural use only (irrigation)

Is water salinity a problem?

Nee

Is flooding of the area occurring?

Nee

Comments and further specifications on water quality and quantity:

Availability of surface water: excess, poor/ none (surface water is only available when rains. Heavy rains produce overland flow)

5.5 Biodiversity

Species diversity:
  • low
Comments and further specifications on biodiversity:

Only trees on cultivations and anual herbs and grasses.

5.6 Characteristics of land users applying the Technology

Sedentary or nomadic:
  • Sedentary
Market orientation of production system:
  • commercial/ market
Off-farm income:
  • less than 10% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
Gender:
  • men
Age of land users:
  • middle-aged

5.7 Average area of land owned or leased 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 ownership:
  • individual, titled
Land use rights:
  • individual
Water 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

fodder production

decreased
increased

fodder quality

decreased
increased

animal production

decreased
increased

wood production

decreased
increased

risk of production failure

increased
decreased

product diversity

decreased
increased

production area

decreased
increased

land management

hindered
simplified
Water availability and quality

demand for irrigation water

increased
decreased
Income and costs

expenses on agricultural inputs

increased
decreased

farm income

decreased
increased

economic disparities

increased
decreased

workload

increased
decreased

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased

water quality

decreased
increased

surface runoff

increased
decreased

excess water drainage

reduced
improved

groundwater table/ aquifer

lowered
recharge

evaporation

increased
decreased
Soil

soil moisture

decreased
increased

soil cover

reduced
improved

soil crusting/ sealing

increased
reduced

soil compaction

increased
reduced

salinity

increased
decreased

soil organic matter/ below ground C

decreased
increased
Biodiversity: vegetation, animals

pest/ disease control

decreased
increased
Climate and disaster risk reduction

fire risk

increased
decreased

wind velocity

increased
decreased

6.2 Off-site impacts the Technology has shown

water availability

decreased
increased

reliable and stable stream flows in dry season

reduced
increased

downstream flooding

increased
reduced

downstream siltation

increased
decreased

groundwater/ river pollution

increased
reduced

buffering/ filtering capacity

reduced
improved

wind transported sediments

increased
reduced

damage on neighbours' fields

increased
reduced

damage on public/ private infrastructure

increased
reduced

impact of greenhouse gases

increased
reduced

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 Type of climatic change/ extreme How does the Technology cope with it?
annual temperature increase not well

Climate-related extremes (disasters)

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

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period not known

6.4 Cost-benefit analysis

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

neutral/ balanced

Long-term returns:

neutral/ balanced

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

neutral/ balanced

Long-term returns:

neutral/ balanced

Comments:

Mulch is seen as an expensive treatment without any advantage.

6.5 Adoption of the Technology

  • single cases/ experimental
Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 0-10%
Comments:

Comments on adoption trend: The owners are not aware because of the costs, but they will change if the government start funding it.

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

Nee

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
It will prevent soil losses and promotes soil organic matter incorporation. High levels of soil moisture will prevent for drought periods.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
It is a technology very easy to apply, with low failure possibilities and a strong soil erosion control and local soil properties improvement.

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

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
The costs are not very high, but enough to discourage the landowners to cover the expenses. Look for Government funding.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
When applying high-density mulches the application labours will be higher. High decomposition rate. Distribute the mulch in strips, and try to reduce the application rate.

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys
  • interviews with land users

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