General
National Id
Spain_04
Site name
"La Conchuela"; commercial olive orchard, 10 km west of Córdoba, Andalusia, south-western Spain.
Summary
Cover Crops and No-Tillage in an Olive Grove (Andalusia, Spain).
"La Conchuela" is commercial olive orchard (Cordoba, Andalusia, Spain) in which alternative soil management practices (no-tillage and green cover) to reduce soil erosion and runoff have been studied during 7 years. This case study shows how the use of a cover crop can be a simple, feasible soil and water conservation practice in olive groves on rolling lands in the region.
"La Conchuela" is commercial olive orchard (Cordoba, Andalusia, Spain) in which alternative soil management practices (no-tillage and green cover) to reduce soil erosion and runoff have been studied during 7 years. This case study shows how the use of a cover crop can be a simple, feasible soil and water conservation practice in olive groves on rolling lands in the region.
NUTS Code
Andalucía
RBD code
ES060
Transboundary
0
Data provider
Fernanda Milans (IMDEA Water) in close cooperation with José Alfonso Gómez (IAS-CSIC) whose valuable contribution is acknowledged and very much appreciated.
Source(s)
NWRM(s) implemented in the case study
Longitude
-4.8980556
Latitude
37.815
Site information
Climate zone
warm temperate dry
Mean rainfall
577
Mean rainfall unit
mm/year
Average temperature
22
Mean runoff
25,8999996185303
Mean runoff unit
450 - 600 mm
Average runoff coefficient
3,09999990463257
Type
Actual Test Site
Light or indepth?
Light
Average slope range
10-15%
Monitoring maintenance
Monitoring impacts effects
1
Performance
Performance impact estimation method
Edge of Field/Plot
Performance impact estimation information
Rainfall, runoff and soil loss were recorded during 7 years under three different soil management systems: no tillage, conventional tillage and cover crops. The results of the three alternatives on soil properties and on runoff and sediment losses were thus compared.
Design & implementations
Application scale
Plot
Lifespan
1
Age
7
Performance timescale
1 - 4 years
Area (ha)
0,0287999995052814
Area subject to Land use change or Management/Practice change (ha)
0,0288800001144409
Design capacity description
Sediment losses: Cover Crops: 0,8; No-Tillage: 6,9 (t ha-1 year -1)
Constraints
Cover crops should be sown in early autumn after the onset of rains. Also the choice of the correct killing date to avoid water competition. They should be mown in early spring in order to prevent competition with the olive tree for water and nutrients. Cover crops can increase the probability of the development of pests an diseases associated to cover crops and increase the probability of wildfires. There are some technical problems related to the seed selection and its maintenance.
Favourable preconditions
The risk of competition for soil, water and nutrients between the tree and the cover crops is minimal in the initial years of the plantation (small and less trees density). Also in the case of irrigated groves that are adequately fertilized.
Design contractual arrangement
| Arrangement type | Responsibility | Role | Comments | Name |
|---|
Design consultation activity
| Activity stage | Key issues | Name | Comments |
|---|
Design land use change
| Land use change type |
|---|
Design authority
| Authority type | Role | Responsibility | Name | Comments |
|---|
Lessons, risks, implications...
Key lessons
The study shows that the use of a cover crop can be a simple, feasible soil and water conservation practice in olive groves on rolling lands in the region. A key factor in its practical use is to establish it early enough to protect the soil in the critical initial years of the grove, when most of the soil is unprotected by the small olive canopy. The no-tillage treatement, bare soil with herbicide, does not benefit soil and water conservation. Despite this work, long-term studies that simultaneously assess the effects of different soil management on soil properties and on soil and runoff losses in olive groves are lacking. The sutdy is based on 7 years of data collection; results may change over a longer period.
Success factor(s)
| Success factor type | Success factor role | Comments | |
|---|---|---|---|
|
Specific incentives for stakeholder involvement
|
main factor
|
Financing
| Financing type | Comments | |
|---|---|---|
|
Local funds
|
The Autonomous Andalusian Government through projects CAO 01-001-C4-0, AGR2005- 00595 and AGR2349.
|
|
|
Private funds
|
INIA through project CAO98-15
|
Driver
| Driver type | Driver role | Comments | |
|---|---|---|---|
|
Balancing different objectives
|
main driver
|
Financing share
| Financing share type | Share | Comments |
|---|
Policy, general governance and design targets
Policy description
To date, 31% of the olive acreage in Andalusia is located on very steep terrains, on slopes of above 15%; 38% of the acreage is on moderate slopes, in the 7-15% range; the rest on slopes of under 7%. Traditional olive production is based on low tree densities weed control via frequent tillage and canopy size limited by pruning, to ensure the productivity and survival of the plantation in a limited rainfall environment. Olive production in the region has been associated with severe soil erosion problems accompanied by fertility depletion and loss of biodiversity.
Policy target
| Target purpose | |
|---|---|
|
Runoff control
|
|
|
Erosion Control
|
Policy pressure
| Pressure directive | Relevant pressure |
|---|
Policy area
| Policy area type | Policy area focus | Name | Comments |
|---|
Policy impact
| Impact directive | Relevant impact |
|---|
Policy wider plan
| Wider plan type | Wider plan focus | Name | Comments |
|---|
Policy requirement directive
| Requirement directive | Specification |
|---|
Socio-economic
Direct benefits information
Economic benefits of improving productivity and avoided cost of improving the soil quality. Economic benefit from reducing tillage (reduce working hours, fuel consumption, machine fix cost).
Ancillary benefits information
CO2 sequestration, reduction in soil erosion, increase soil and water storage capacity and enhanced biodiversity
Information on Economic costs - income loss
Economic cost of increase in the use of herbicide and application cost
Ecosystem improved biodiversity
1
Information on Ecosystem improved biodiversity
Changing from bare soil managements (CC and NT) to the use of CC (where the amount of herbicide and frequency of tillage is reduced) increase the biodiversity of the agricultural system (De la Concha et al., 2007). Reducing tillage and heavy herbicide enhance the specturm ground flora and on insect populations. Moreover a permanent grass cover, managed by mowing or grazing, benefits soil and wildlife conservation (Beaufoy, 2001).
Ecosystem provisioning services
0
Ecosystem impact climate regulation
Impact on GHGs (net emissions and storage) including soil carbon
Information on Ecosystem impact climate regulation
Soil carbon sequestration in olives grove derived from the implementation of agricultural practices, mainly by reducing tillage (as in the case of CC management practices) significantly increase by up to 0.3 tons per hectare and year (Rodríguez et al., 2012). Changing from bare soil practices to the use of plant covers in combination with tillage or residual herbicide application, improves soil structure due to an increase in the organic matter (Gómez-Calero et al., 2009) thus allowing for the improvement of the carbon sink capacity of the olive agricultural system.
Biophysical impacts
Information on retained water
This is still to be defined in co-operation with practitioners. We are working with researchers on soil conservation measures on this water retention potential.
Information on increased water storage
Cover crops increase the infiltration rate and surface storage
Information on runoff reduction
Lower runoff coefficient in the Cover Crop treatment as compared to the Conventional Tillage and No-Tillage treatments. Higher runoff coeficient in the No-tillage system compare to the base line (Conventional Tillage). Average values (200-2006) runoff coefficient: NT: 11.9% / CT: 3.1% / CC:1.2%
Water quality overall improvements
Positive impact-WQ improvement
Information on Water quality overall improvements
In the cover crops treatment the water infiltrated more easily into the soil (under the protective plants) and at the same time the increased flow resistence dissipated the energy of the surface water. The aereal part of the plant intercepted part of the sediment particles carried by the water (Gómez et al., 2009)
Soil quality overall soil improvements
Positive impact-SQ improvement
Information on Soil quality overall soil improvements
Positive impacto on soil quality under Cover Crops soil management (the capacity of plant covers in intercepting rainfall is a determining factor in the reduction of soil erosion, which subsequently avoids the development of impermeable crusts at the soil surface). No tillage treatment, bare soil with herbicide, does not benefit soil and water conservation compared to the traditional, Convemtional tillage, or the innovative, Cover crop.
