The agriculture of a province is often explained through its climate and its water, yet every decision about production depends first on the soil itself: its depth, texture, slope and nutrient load. In Amasya this ground is not uniform. The province consists of narrow valleys opened by the Yeşilırmak and its tributaries and of plain floors lying between mountain masses such as the Canik, Akdağ, Karaömer, Sakarat and Tavşan ranges. Its rugged surface, which runs from 160 to 2,061 metres above sea level, has caused soils to form under quite different conditions. The geography of the plains and the crop pattern belong to a separate article. Here the focus is on the soil types, how they are classified, and how land is used according to its capability.

Factors That Shape Soil Formation

Soil emerges over long periods as parent rock weathers under the influence of climate, vegetation and topography. In Amasya all three factors change over short distances. The province lies in a belt of transition from the Black Sea climate to the continental climate of the interior; at the provincial centre the mean annual precipitation is 436.7 mm, the mean temperature 13.6 degrees and the elevation 411.69 metres. Precipitation ranges from 436 to 458 mm at Gümüşhacıköy and Merzifon and falls to 400 mm at Taşova. Rain is heaviest in spring and lightest in July and August, a pattern that increases the pressure of summer drought on the soil.

The picture changes with altitude. On the north-facing slopes of the Akdağ and Boğalı Dağ ranges, good-quality beech forests begin above 1,000 metres; on the south-facing slopes, belts of red pine, oak species, black pine and Scots pine rise one after another from the Yeşilırmak Valley. Göynücek in the south lies on the way to Central Anatolia and therefore carries a steppe cover, with forests made up mostly of oak coppice and a small amount of juniper. Soil structure and organic matter content develop in a different direction in each of these vegetation belts. This is why traits of both humid forest soil and steppe soil can be found within the same provincial borders.

Valley-Floor and Slope Soils

In the broadest framework the soils of the province fall into two groups: valley-floor soils and slope soils. Floor soils are generally formed from sediments, that is alluvium, left by the Yeşilırmak, its tributaries and side streams. On the slopes, soil texture varies across a wide range from light to heavy. Simple as it appears, this twofold division reflects the logic of the province's soils accurately: material carried and deposited on the plains by water behaves very differently from material that weathers in place and moves with the slope.

Across Turkey, soil types are studied under two main headings, residual and transported. Residual soils form where the parent rock weathers under the climate and vegetation of the place, and because they reflect the climate they are counted as zonal soils. Transported soils form from material brought by rivers or by slope processes and then deposited. The floor soils of Amasya belong to the second group, while its slope and highland soils belong mainly to the first.

Alluvial Soils

Alluvial soils form where the gravel, sand and silt carried by rivers accumulate on flat or gently sloping ground. Because they come into being independently of climate, they are called azonal soils. They are deep and permeable and rich in plant nutrients, and since they consist of sand, clay and gravel they are easy to work. A large part of Turkey's most productive farmland lies on these soils, and the subsidence plains along the North Anatolian Fault Zone belong to the same group.

The clearest example of alluvium in Amasya is the Yeşilırmak Valley. The 519-kilometre river, rising in the Köse Mountains of Sivas, flows for about 129 kilometres within the province; it is joined by the Çekerek from the south, by the Tersakan at the city centre and by the Kelkit near Taşova. The valley consists of very fertile alluvial soils and, thanks to a climate with microclimate characteristics, stands out for fruit and vegetable growing. The Onlukköprü Valley, where the Amasya apple is grown, lies within this strip. Floods on the Yeşilırmak generally occur in March, April and May, and the alluvial cover of the valley floors has been nourished by this seasonal flow.

The soils of the plain floors likewise rest on river and lake deposits. The Geldingen, Suluova, Merzifon and Gümüş plains together cover about 24 percent of the province's area. The Geldingen Plain, at roughly 48,400 hectares the largest in the province, was formed by the erosion of the Çekerek River, the Çorum Stream and the Efennik Stream; the Suluova Plain spreads on both sides of the Tersakan over about 40,000 hectares; the Merzifon Plain is 31,100 hectares and the Gümüş Plain 5,400. What matters for soil is that, because these floors are deep and flat, they are the most easily worked land in the province wherever irrigation is available.

Colluvial Soils

Colluvial soils, the second type of transported soil, differ from alluvial soils in that they do not travel far from where they were eroded; material broken from a slope accumulates immediately at its foot. Because they have not completed their formation, no horizons have developed, but they are deep and permeable. Where the topography is suitable they are used for vineyards and gardens. In a province of frequent valley slopes such as Amasya, soils of this kind form the expected transitional belt at slope bases and stream mouths, where the flat floor ends.

Forest Soils

Soils formed under forest cover are rich in organic matter and dark in colour. In Turkey they are widespread across most of the Black Sea Region and in the forested areas of Central Anatolia above 1,200 metres. According to rainfall they are divided into non-calcareous and calcareous forest soils. Non-calcareous forest soils develop in cold, humid places where mean annual temperature does not exceed 8-9 degrees and precipitation is above a thousand millimetres, under trees such as beech, Scots pine and spruce; because of excessive leaching they are poor in nutrients and acidic in reaction. The north-facing slopes of Amasya that carry beech forests above 1,000 metres are the part closest to this development. Since the province's rainfall generally stays below that threshold, the non-calcareous type is expected only locally and over limited areas.

Calcareous forest soils arise where annual rainfall is insufficient and carbonate material cannot be removed from the soil. Lime accumulates in nodules just below the surface. They are common under oak forests on the south-facing slopes of the North Anatolian mountains and in inland regions. Their organic matter is not high enough to make them very dark, which is why they are also called brown forest soils. The southern slopes of the Yeşilırmak Valley, the lower southern flanks of Tavşan Dağı at Merzifon and the oak forests of Hamamözü fit this description. The general view that the slope soils of the province consist mainly of brown forest soils rests on the same reasoning.

The shared trait of forest soils is that they are unsuited to agriculture. In non-calcareous forest soils heavy rain has leached nutrients away to a great extent. Where forest is destroyed and fields are opened, severe erosion sets in and the soil becomes unproductive within a few years. For this reason it is recommended that field farming not be practised on such land and that the area be kept as forest. The separation of forest and pasture from cultivation on the slopes of Amasya rests on this scientific reasoning.

Steppe Soils and the Southern Part

Steppe soils, which form under semi-arid conditions in areas without forest cover, are the characteristic soil group of Central Anatolia. Among them, brown steppe soils develop where annual rainfall remains around 300-400 mm. Leaching is weak, lime accumulation just below the surface is marked, and they are mostly used for grain farming. These soils, poor in nutrients, raise their yield when irrigated and fertilised. Chestnut-coloured soils form where annual rainfall is 400 mm or more, under tall grasses, oak forests and shrubs; they are dark because the upper horizons hold enough organic matter. Part of them has been opened to farming, while the high and rugged portions have been used as pasture.

The south of Amasya, especially around Göynücek and Geldingen, falls in this transitional belt. The Geldingen Plain, with 400-500 mm of annual rainfall, receives the least precipitation in the province and a continental climate prevails. Soils here are expected to be prone to drought and to give limited yields without irrigation. The agricultural future of the plain has therefore been seen as dependent on completing irrigation works such as the Süreyyabey Dam on the Çekerek, while the sharp drop in summer water and the pollution of irrigation sources have been named as problems.

Land Resources of the Province

The total area of Amasya is given as 5,701 square kilometres in some sources and 5,628 in others. According to the 2009 data of the Provincial Directorate of Agriculture, 44.4 percent of the area, or 253,029 hectares, is agricultural land. Of this, 174,366 hectares is dry-farmed and 78,663 hectares irrigated; in other words about one third of the farmland can be irrigated. The weight of dry farming shows how large the rain-dependent part of the province's soil is. The main crops are field crops such as wheat, sugar beet, dry onion, sunflower and poppy, together with apple, cherry and peach, while vegetable growing has been shifting in recent years from open fields to greenhouses.

According to the same source, 179,988 people from about 35,998 farming families in the province earn their living from agriculture. In 2009 the monetary value of agricultural production came close to 1.1 billion liras, of which 73.17 percent came from crops and 26.83 percent from livestock. At the end of that year the province counted 136,851 cattle, 106,626 sheep and goats, 1,162,215 poultry and 14,850 beehives. That livestock keeping is generally run as family enterprise makes the place of pastures and highlands in land use understandable, since grazing is the main use that puts slope and highland soils unfit for cultivation to work.

Land Use Capability Classes

The most widely used yardstick for deciding what purpose a soil should serve is the land use capability classification. The system rests on the joint assessment of effective profile depth, texture, permeability, degree of erosion, stoniness, salinity, topography and drainage, and it divides land into eight classes from I to VIII. As the class number rises, the alternative uses that can be chosen narrow, and the limitations and hazards of use grow. The first four classes are suitable for tillage; the last four are not, because of the limiting factors they carry. The suitability of Class IV for farming is assessed separately after land use planning.

Class I, II and III lands are counted as absolute agricultural land and should not be used for non-agricultural purposes unless unavoidable. Class IV soil is potential agricultural land, and part of it can be used as pasture after planning. Class V is mostly meadow land. Classes VI and VII are land unsuited to tillage, to be used primarily as pasture and forest; Class VIII covers land without soil, stony, rocky or highly saline. Across Turkey, Class I land makes up 5.1 million hectares or 6.5 percent of all land, Classes II and III make up 8.7 and 9.3 percent, and Class VII holds about half. The share of productive land suited to tillage is lower than commonly supposed and amounts to roughly one third of the land mass.

The provincial table by Cangir and Boyraz shows, class by class, the land used wrongly or for purposes other than its capability in Amasya. According to the table, Class I land in the province carries 56 hectares of pasture use, 326 hectares of forest and 1,191 hectares of settlement; for Class II the same items are 797, 59 and 410, for Class III 71, 2,276 and 989, and for Class IV 4,890, 6,267 and 730 hectares. Put differently, about 6,200 hectares of Class I, II and III land, counted as absolute agricultural soil, is under non-agricultural use, much of it under settlement or forest. The same table shows 17,106 hectares of Class VI land and 23,167 hectares of Class VII land under tillage; by definition of the classes these are fields ploughed on soils unsuited to tillage. These figures point to a two-sided problem: good soil given over to settlement, weak soil opened to the plough.

Erosion and Soil Protection

Among the factors that increase erosion in Turkey are intense and irregular rainfall, steep slopes, the prevalence of loose-textured parent rock and soils, excessive and faulty tillage, overgrazing of pastures, widespread fallowing, forest fires, flash floods and frequently recurring landslides. The Black Sea mountains are among the areas exposed to severe erosion, and it is reported that more than 500 million tonnes of soil are carried away by erosion every year across the country. In Amasya, a steep, slope-dominated province, this risk is most pronounced on slope and highland land.

The highlands are the clearest example. The Akdağ, Tavşandağı, Kabaoğuz, Destek and Boğalı plateaus, lying in the transition zone between the Black Sea and Central Anatolian climates, hold the plants of both. Yet overgrazing, field opening and excessive use of agricultural chemicals and fertiliser are reported to have degraded the plateaus, so that in the upper parts bedrock has nearly surfaced, old trees in the forests at the plateau edges are not being replaced by young ones, and the forest line is sinking lower. Protective measures proposed include afforestation, protection of pasture and forest, improvement of flood-prone river beds, terracing and attention to slope direction on sloping land, crop rotation, not burning stubble and reducing fallow. Choosing farming activity to suit the soil type is the shared principle of these measures.

On the valley floors the risk lies in another direction. Although irrigation water quality is generally good, pollution problems have appeared in recent years, and the sharp fall of water in summer makes irrigation difficult on the Geldingen Plain. Salinisation is a problem seen where the water table is near the surface and evaporation is high, so balanced irrigation on flat plain soils is needed for yields to last. The spread of greenhouses adds a further dimension to soil management, since covered production means continuous planting and fertilising on the same soil.

Distribution of the Land

In broad outline, land use in Amasya follows the capability of the soil. Deep, flat alluvial floors rich in nutrients have been given over to vegetables, fruit and industrial crops; in the central and southern parts, where calcareous forest soils and steppe soils lie, grain and dry farming have been practised; and the high, sloping hillsides have remained forest and pasture. Two situations disturb this distribution: the opening of fertile farmland to settlement and construction, and the ploughing of sloping, shallow soils.

Sources

Books

Other sources

Online sources