Cropland
Characteristics of cropland: Spain and Canyoles River Basin
Author: Artemio CerdaEditor's note 30 Apr 2012: Text source D111-2.5. To be edited again to avoid overlap with D131.
Characteristics of Cropland in Spain
Spain produces twelve per cent of total European cropland production. Fruits, vegetables, olive oil, wine and cereals are the main products of Spanish agriculture. Fifty-two percent of Spanish farms are smaller than 5 ha; only five percent of farms are larger than 100 ha. Most farmers are aged over 55 years (55 percent). Spanish agricultural land covers 26,000 ha (the second largest area in Europe after France). Rainfed agriculture is the most widespread system, although the area under irrigated agriculture is increasing rapidly. Agro-chemicals are particularly intensively used on irrigated land, especially in the Southeastern region. Ploughing is the traditional and most commonly used management technique; however, the use of herbicides is now increasing. On irrigated land, the management technique is mainly to use herbicides and pesticides.
Characteristics of Cropland in the Júcar River Basin
The Júcar River Basin covers more than 4 million ha and comprises 5 provinces of Spain (Figure 1). This study area is representative of the LEDD processes that take place in the North of the Mediterranean basin. The research developed by the Soil Erosion and Degradation Research Group (SEDER) from the University of Valencia is focussed on the Júcar River Basin, and on a smaller watershed; the Canyoles River watershed, which was selected to study the main LEDD processes in more detail (Figure 1). The Canyoles River watershed covers 62,000 ha and shows a gradient from east to west, from the more economically active land near the coast towards more depopulated country inland.
The Júcar River Basin is located in the East of the Iberian Peninsula (Table 1) and drains an area of 4,287,020 ha. Urban water use is 118,64 hm³ / year for 1,030,979 inhabitants and the irrigated surface is 187,855 ha, consuming 1,394 hm³ / year. The territory of the Júcar river Basin (Ordenance 650/1987, 8th of May) includes all watersheds that drain into the Mediterranean Sea between the rivers Segura and Cenia. Included in this area are the provinces of Albacete, Alicante, Castellón, Cuenca, Tarragona, Teruel, and Valencia and its municipalities.
Table 1. Geographical position of the Júcar and Canyoles Rivers.
| X/Y | X minimum | X maximum | Y minimum | Y maximum | |
| 1 | JRB | 542000,19 | 798198,44 | 4222337,50 | 4517812,00 |
| CRB | 667050,00 | 716850,00 | 4292350,00 | 4324350,00 | |
| 2 | JRB | 2°31’14.47’’ | 0°31’56.04’’ | 38°08’50.29’’ | 40°45’23.46’’ |
| CRB | 1°04’38.58’’ | 0°29’40.43’’ | 38°45’48.29’’ | 39°02’26.41’’ |
JBR: Júcar River Basin CRB: Canyoles River Basin 1: ED50, Zone 30 2: WGS1984, Zone 30
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Figure 1. Location of the study area of the Canyoles River Basin within the Júcar River watershed. Source: (González Peñaloza and Cerdà 2011) |
The Canyoles River Basin is located in the south of Valencia province, in an area of 62,826 hectares and includes 24 municipalities (Figure 2). The Canyoles River Basin does not cover all of those municipalities entirely, as some of them only contribute a few m² to the watershed. The climate of the study site is characterised by a typical Mediterranean contrasted climate with dry and hot summers and wet and mild winters, although the winters inland are cold due to the effect of altitude. The study area of the Canyoles River comprises a watershed that increases from 100 to 1,000 m in altitude.
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Figure 2. Municipalities of the Canyoles River Basin. Source: (González Peñaloza and Cerdà 2011) |
The Júcar River Basin has a Mediterranean climate, with warm, dry – hot summers and wet – warm winters. The climate is the result of the presence for most of the year of the Azores anticyclone on the Iberian Peninsula. This weather pattern has an exception; in October and November there appears a meteorological phenomenon, called a "cold drop" which results in high rainfall intensities and volumes. The upper basin area has a more continental climate, with average annual rainfall between 400 and 900 mm which falls mainly in spring and autumn, and an average air temperature between 10 and 12°C. However, the coast has a temperate dry Mediterranean climate, with average air temperature of 17°C, high humidity (60%), and average annual precipitations between 400 and 800 mm, with maximum monthly in spring and autumn (Alicante).
The summer is characterized by a drought of three to five months duration, which makes irrigation necessary in order to achieve the highest productivity. Irrigation is also widespread due to high evapotranspiration rates. Evapotranspiration rates are higher near the coast due to the higher temperatures.
The study area is located in the south of the Iberian System and the Betic System. Both are characterised by rugged terrain and steep slopes. This is why most of the Júcar basin shows rolling and gently undulating landforms, and also steep slopes and rugged terrain. Flat surfaces cover the bottom of the valleys and in the upper part of the mountains, where flat surfaces can be found (Table 2). The Canyoles River Basin shows a greater relief (see Table 3) due to the fact that the river Canyoles flows in the border between the Iberian System and the Betic System. The fault developed in this contact contributes the steep slopes and incised valleys.
Table 2. Regional landforms and associated area
| Landform | Area (hectares) |
| Flat | 1674938.33 |
| Undulating | 894169.21 |
| Gently undulating | 11251500.21 |
| Rolling | 520005.70 |
| Moderately steep | 68785.13 |
| Steep | 618.18 |
| Very steep | 0.00 |
Source: (González Peñaloza and Cerdà 2011)
Table 3. Slope map of the Canyoles River Basin
| Landform | Area (hectares) |
| Flat | 9876.92 |
| Undulating | 7071.11 |
| Gently undulating | 11926.21 |
| Rolling | 19941.38 |
| Moderately steep | 11273.97 |
| Steep | 2416.26 |
| Very steep | 10.98 |
Source: (González Peñaloza and Cerdà 2011)
The parent material of local soils is mainly limestone, although some marls, Keuper clays and quaternary sedimentary material can also be found (Table 4). The Karst type landscape is widespread, and is very important for understanding the geomorphology and hydrology of the study area, as groundwater flow and cave and pipe systems are widespread. Three main geomorphologic units are found: mountains ranges; plateau; and coastal plain. The Canyoles River watershed is characterised by a north and south range that contribute to a long W-E valley flowing from inland in the Iberian Peninsula, to the Mediterranean Sea.
The Mountain range in the north of the Júcar River Basin is known as the Iberian System, comprised of Mesozoic material, which has been folded and deformed by the Alpine orogeny. The highest peak in this range is Pañarroya (2019 metres above sea level). The Iberian System is located in the north of the Canyoles valley and plays an important role in the water resources cycle in the Júcar River Basin, because the range acts as a barrier for sea fronts, forcing clouds carrying moist air to rise to colder upper layers of the atmosphere. Once the air is lifted and cooled, it causes the largest rainfall located near the sea.
Table 4. Geology of Júcar River Basin
| Lithology | Era | Period | Area (hectares) |
| Other | - |
- |
50427.53 |
| Sandstones, conglomerates, clays, limestones and evaporites | Cenozoic | Neogene | 1004206.94 |
| Sandstone, shale and limestone | Paleozoic | Silurian | 2682.35 |
| Detrital limestone, calcarenite, marl, clay and limestone | Cenozoic | Paleogene | 81060.19 |
| Limestone, dolomite and marl. Sandstones and conglomerates | Mesozoic | Jurassic | 772170.01 |
| Conglomerates, sandstones, clays and limestone. Evaporites | Cenozoic | Cretaceous-Paleogene | 104842.46 |
| Conglomerate, sandstone, limestone, gypsum and clay versicolor | Mesozoic | Permian-Triassic | 330809.17 |
| Conglomerates, sandstones, shales and limestones. Coal | Paleozoic | Carboniferous | 2011.53 |
| Quartzite, slate, sandstone and limestone | Paleozoic | Ordovician | 3321.13 |
| Dolomite, limestone and marl. Sandstone | Mesozoic | Cretaceous | 1153960.57 |
| Gravels, conglomerates, sands and silts | Cenozoic | Quaternary | 772554.84 |
| Volcanics and volcaniclastic rocks | Cenozoic | Neogene - Quaternary | 416.96 |
Source: (González Peñaloza and Cerdà 2011)
The coastal plain is an alluvial plain, over 400 km long and 40 km widest its widest section. This coastal plan is delimited by the Iberian System in the North West, the continental plateau on the west and the Betic System in the south. There is also an area of flat land called the Mancha area. With an average height of 650m, it is located in the western part of the Júcar River Basin.
The soils of the Júcar River watershed are classified mainly as Calcic cambisols due to the extended limestone in the area (Table 5). The soils of the study area have been affected by millennia of grazing, ploughing and burning. This is why most of the soil shows shallow depths and a poor soil structure. The Canyoles River watershed is characterised by a north and south range that contribute to a long W-E valley flowing from inland in the Iberian Peninsula to the Mediterranean Sea.
The parent material also contributes to hydrological resources based on aquifers and springs which supply water for irrigation and urban use. The river system is characterised by ephemeral rivers that flow during the rainy season, but during the summer period are dry. This is due to the Mediterranean climatic conditions and the parent material, which contributes to a karst system of springs and dry rivers. Moreover, the hydrological system is now completely controlled by human activity, with rivers flowing in summer for irrigation and without flow in winter due to the dam flow control on the Jucar River system, which supplies the cities and coastal zone with drinking, irrigation and industrial water.
Table 5. Area covered by the main soil types (ha)
| Soils | Area (Hectares) |
| Others | 21950.38 |
| Calcaric lithosol | 3045.90 |
| Calcic cambisol | 3424179.53 |
| Calcic luvisol | 40445.48 |
| Calcic xerosol | 234980.26 |
| Dystric planosol | 853.26 |
| Eutric cambisol | 46391.04 |
| Eutric fluvisol | 268192.90 |
| Gleyic cambisol | 185177.61 |
| Gleyic solonchak | 13834.55 |
| Gypsic xerosol | 7874.87 |
| Humic cambisol |
24601.17 |
Source: (González Peñaloza and Cerdà 2011)
The vegetation is dominated by crops (olive, almond, fruit trees, cereals, vegetables, vineyards and citrus) and a maquia and garrigue scrubland-type vegetation mixed with Aleppo pine. The oak forest was removed by human activities (grazing, fires, ploughing and timber extraction) and oaks are now found in few sites. Fauna is adapted to the presence of humans, and domestic animals are the most widespread.
Croplands are mostly rainfed in the upper part of the basin, although during the last decade irrigation is being introduced on some farms to support wheat and mainly maize production. The use of drip irrigation is also increasing, particularly for vines. In the lower part of the valley, the irrigation system was developed millennia ago by means of flooding, however, during the last two decades an increase in drip irrigation has almost removed flooding irrigation from most farms.