Study Site Trials

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

Country General Treatment Category Study Site Trials
Portugal 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)


Geographical description

The two study areas are located in the Mondego lower valley, an alluvium plane area located between Coimbra at the east and the sea to the west. Rainfall is around 1000mm.yr-1, Wet Mediterranean climate, with dry summers, the soils are alluvial soils built on naturally during historical times (due to the floods of the Mondego River. The entire valley is between 0 and 25 meters above sea level. The east part is mainly used for corn, while the west, closer to the river mouth is used mainly for rice.

Pedo-climatic zone
Lusitanean, silty-clayey soils

Cropping systems

Cropping intensity
Maize: We will make a comparison between the conventional and the organic cropping systems, and will study the demands of the new Common Agriculture Policy in terms of crop rotation. Use of conventional varieties. 

Rice: We will study mainly the conventional and organic cropping systems, and the potential for other land uses. A special attention will be given to the reduction of the flooded time period. Dry seeding is another potential technique to reduce the environmental impacts. There is a process of transferring the rice fields to maize fields, due to the environmental impacts of

Vineyards: The vineyards will be studied in what concerns the management of the grass in-between the plant orchards. This includes a non-tillage conservative approach and the traditional tillage to include the grasses and pruning materials within the soil.

Types of crop
Crops: Maize, Rice and Vineyards

Maize: first year with Maize second year with potatoes and 2 years of Lucerne Medicago sativa L. at the end. In the winter we can have a cover-crop Lupinus luteos or turnips or oats, that then is included in the soil.

Rice: first year with rice second year with maize and 2 years of Lucerne Medicago sativa L. at the end. No winter cover-crops are used, the fields are flooded. We will study the introduction of a cover-crop for environmental reasons

Vineyards are a permanent culture. For this reason, different management options will be addressed, namely in what concerns the use (or not) of tillage, and the incorporation of different organic matter amounts in the soil to assess soil quality

Management of soil, water, nutrients and pests

Maize: Chisel tillage in the conventional system, for the organic before the chisel ploughing the soil is tilled with a disc harrow. Irrigation is delivered with a pivot. In the conventional low release fertilizers will be used, in the organic we will use compost fertilizers produced at ESAC. ESAC uses the standard pesticides authorized for the conventional and organic farming.

Rice: mouldboard plough for both conventional and organic systems, a seed bed preparation is performed with a rotary harrow. Irrigation is by flooding. Conventional fertilization for the conventional system, and approved products are used in the organic. The rotation with Lucerne implies that the fertilization is not needed in the first year after the rotation. Herbicides are used in the conventional whereas in the organic a manual weeding is performed.

Vineyards: in the conventional system, soil is tilled with a disk harrow, while in the organic system, grasses are allowed to colonise the space between the vineyard lines. In addition, there is a reduction of the pesticides used in the organic system and a more judicious use of fertilizers (that in some cases are organic compost fertilizers). 

The conventional systems in Portugal are considered sustainable agriculture.

Soil improving cropping system and techniques currently used
The foreseen improvements are threefold:

  • Implementation of more organic systems, including the use of compost and reduction of synthetic fertilizers and pesticides.
  • The implementation of rotation, which is in line with the new common agriculture policy requirements, so to some extent SOILCARE will address the impacts of the novel CAP policies.
  • Optimization of irrigation, also in line with the new policy framework on water that will increase the price of water.

Problems that cause yield loss or increased costs
SOILCARE will be used assess the new policies and tendencies that are undergoing or will shortly be implemented in Portugal, namely a shift from traditional to organic systems, the introduction of rotation, which will be pushed by the novel CAP, and the increase in the price of water, that will require a more judicious use. 

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.