Study Site Trials

The SICS selected for trialling in this Study Site are described below:

General Treatment Category Study Site Trials
Crop rotations, cover crops, fertilization

1. Bico da Barca - Organic rice in rotation with perennial lucerne - Conventional rice monoculture (Control); Organic rice in rotation with perennial Lucerne (2 years of rice + 2 years of Lucerne)

2. Taveiro – Conventional grain corn in succession with legumes winter cover - Conventional grain corn with Red Clover as cover crop in winter; Conventional grain corn with Persian clover as cover crop in winter; Conventional grain corn with yellow lupine as cover crop in winter; Conventional grain corn with white lupine as cover crop in winter; Conventional grain corn with no cover crop in winter (fallow- control)

3. São Silvestre - Conventional grain corn fertilized by urban sludge - Grain corn receiving urban sludge fertilization; Grain corn receiving conventional mineral fertilization (control)

4. Loreto – Conventional grain corn in succession with legumes winter cover - Conventional grain corn with Forage Pea as cover crop in winter; Conventional grain corn with Red Clover as cover crop in winter; Conventional grain corn with Yellow Lupine as cover crop in winter; Conventional grain corn with Balansa Clover as cover crop in winter; Conventional grain corn with Arrowleaf Clover as cover crop in winter; Conventional grain corn with no cover crop in winter (fallow- control)

 

Study Site poster 2018 EGU 2019 Study Site poster (download)

 

SICS 1 :- Rotation system - Bico da Barca – Organic Rice in rotation with perennial lucerne (two years of rice + 2 years of Lucerne)

 

   SICS1a

 SICS1b

 SICS1c

 

 

SICS 2 :- Succession system - Taviero – Principal crop (grain corn or sunflower) integrated in a succession of legumes (clover, trefoil….) used as green manure

 

 Yellow lupin cover crop  cover crop6

 cover crop4

 cover crop5

 

SICS 3 :- Organic fertilization system - São Silvestre - Organic fertilization system from urban origin (sewage sludge)

 

 SICS3a  SICS3b

 SICS3c

 SICS3d

 

SICS 4 :- Succession system - Loreto - Principal crop (grain corn ) integrated in a succession of legumes (clover, pea, trefoil….) used as green manure.

 

 SICS4a  SICS4b

 SICS4c

 SICS4d

 

Geographical description

The study areas are located in the Lower Mondego river valley, an alluvium plane situated in Central Portugal. The valley is roughly east-west oriented and 40 km long (from the Coimbra city to the estuary near Figueira da Foz) and bordered by gently sloping hills. The floodplain cover about 15.000 ha of fertile land and have traditionally been used for irrigated agriculture.

The entire valley is between 0 and 25 meters above sea level. Soils are modern alluvial soils, with a texture from silt-loam to sandy-clay-loam. Climate is Mediterranean, characterized by rainy winters and dry summers, more precisely a Csa climate under the Köppen climate classification, " Hot-summer mediterranean climate ". The annual average temperature is 16.1ºC, with smooth variations. The annual average precipitation is 922 mm, essentially concentrated between October and March.

The Baixo Mondego valley is mainly dedicated to monoculture of irrigated corn grain and flooding rice. The eastern part is mainly used for corn, while the western area, closer to the river mouth, is used mainly for rice.

 Map

Cropping systems

Conventional tillage is practiced with various passes of heavy machinery. Disc harrow passes for straw stubble incorporation, furrow plough passes for soil inversion, chisel and rotary tiller passes to prepare seedbed.

In 1970, the hydro-agricultural exploitation project of the Mondego Valley started that effects about 12.300 ha (total irrigation perimeter). It considers the development and restructuration of agricultural system which involves: property reparcelling, soil levelling and the creation of new irrigation and drainage systems. To date about 6.700 ha are equipped. Irrigation is principally performed with surface furrow irrigation systems, by gravity fed. Soils are levelled and water flows passively on furrows opened between each line of maize. Compared to pressurized systems (sprinkler and drip), surface irrigation systems require lower capital investment. However, some farmers also use pivot irrigation systems.

Production is based on expensive production factors: mineral fertilizers to compensate for the important soil nutrient exportation after harvesting, pesticides for pest control problems driven by intensive monoculture.

Soil improving cropping system and techniques currently used

Concerning rice cropping systems, the DRAP-Centro is currently monitoring a long term experiment (for about 10 years) that involves a cropping system composed of organic rice in rotation with perennial lucerne (two years of rice followed by two years of lucerne). The introduction of a legume in the rotation provides an increase of the nitrogen available for rice production and is benefical for pests and weeds control.

Concerning maize cropping systems, some farmers use organic amendments such as urban sludge, but it is a very controversial issue. A small number of farmers have introduced legumes or mix of legumes and gramineous as cover crop during the winter, but it’s not a very common technique.

 

External drivers or factors

Institutional and political drivers

As previously stated, part of the SoilCare effort made by the Portuguese (ESAC) team will be a consequence of the implementation of the forthcoming new priorities set by the Common Agriculture Policy. In addition, the new reading made of water framework directive will imply an increase of the water price for agriculture.

Societal drivers

There is an ongoing tendency to shift from the traditional to the organic systems which is pushed by a younger and urban population fringe. This implies that the organic farming systems are gaining territory.

Bio-physical drivers

Being under a wet Mediterranean type of climate, the Portuguese study areas are affected by water shortages that occur during the vegetative growth season. The absence of proper irrigation systems and the proper water amounts for irrigation have an overwhelming effect on crop productivity.