Saturday, 15 July 2006
148-1

Romanian Soil Irrigation Feasibility.

Ion Seceleanu Sr., National Institute for Research and Development for Soil Science, Agrochemistry and Environmental Protection-ICPA, 10, Sos. Iancului, Bl. 114B, Sc. A, Ap. 34, Et. 8, Sector 2, Bucuresti, Romania

As a result of the visible increase in productivity in irrigated areas, especially during drought seasons, a series of large irrigation systems were developed in Romania using the Danube River as a water source. Irrigation was especially successful on the Romanian Plain and in Dobrogea, where average temperatures are 9-11 degrees Celsius, average annual rainfall is 350-620 mm, and reference evapotranspiration Thornthwaite (ETo-TH) is 700 mm. There were also local irrigation systems that used larger rivers as their water source. An area of 3.2 million ha was irrigated by these systems. Since 1989, most of the existing irrigation systems have been completely or partially abandoned or destroyed and work on all units has ceased. Some of the partially or totally destroyed irrigation networks have been restored using state funding. As of 2003, the area under irrigation was 781,000 ha. With Romania's accession to the EU, a vast restoration program is planned for an area of 700,000 ha that was served by the old irrigation systems; the final irrigated area is expected to reach a surface of 4 million ha. As a result of the planned restoration of irrigation, I.C.P.A. Bucharest issued a methodology for soil study research that would precede irrigation construction to eliminate risks to soil quality associated with irrigation. Fields were assessed for irrigation needs using the ‘humidity deficit' indicator, which takes climatic conditions into account. Results of the assessment indicated that lands with a high humidity deficit, specifically Dobrogea and the Eastern Romanian Plain, do require irrigation. Also, areas with high humidity deficit on the Moldavian Plain and the Western Romanian Plain require moderate irrigation. Lands on the Tisa Plain with a moderate humidity deficit will require less irrigation. Irrigated soil behavior was classified to devise selection criteria for agricultural lands with irrigation needs. Six classes of irrigation feasibility were established as follows: Class I– very good land for irrigation, lacking any kind of degradation risk. This class comprises flat, horizontal, or slightly inclined terrains (2% slope), with deep soils of average to fine-average texture uniform throughout the soil profile. They also have good permeability and good natural drainage. Phreatic water is more than 5m below the surface. These soils are not prone to erosion, excess humidity, salinisation, alcalisation, or flooding. These lands are found on the Romanian Plain, the Tisa Plain, and in Eastern Dobrogea and are characterized by Entic Haplustolls, Entic Hapludolls, Typic Calciustols, and Typic Eutrocryepts. Class II – good land for irrigation, with little degradation and few agricultural use limitations; limitations are based on one or more soil factors such as rock type, salinisation, alcalisation, relief, erosion, drainage, or flooding. These lands can be irrigated with appropriate prevention measures. They do not pose difficult implementation problems because they need relatively little investment and can be ameliorated using usual methods. These lands are found on the Romanian Plain, the Tisa Plain, the Moldavian Plateau, in Western Dobrogea, and on the Transylvania Plain, and are characterized by clay-sandy Typic Calciustols, Alfic Argiudolls, Typic Hapludalfs, Typic Haplustalfs, and Typic Ustifluvents. Class III – moderate irrigation feasibility, with moderate degradation and moderate agricultural use limitations based on one or more factors mentioned above. These terrains can be irrigated with moderate restrictions, protection measures, and improvement. These lands are located on the Tisa Plain, on the Northern Romanian Plain, and on the Southern Getic Piedmont and are characterized by Typic Hapludalfs, Albaquic Hapludalfs, Vertic Hapludolls, Typic Udisammnents, Endoaquic Eutrudepts, and Endoaquic Udifluvents. Class IV – lower irrigation feasibility lands, with high degradation potential and agricultural (arable) use limitations; they have severely restricted irrigation feasibility and need intensive improvement and protection that require extensive investments. These lands are not appropriate for irrigation, except for special crops such as rice, vegetables, or pasture. These lands are located in river valleys, in depressions, and on some slopes characterized by Glossic Hapludalfs, Albaquic Hapludalfs, Typic Epiaquepts, Typic Udisammnents, Typic Endoaquepts and Aquic Haplustepts. Class V – lowest irrigation feasibility lands, very degraded or requiring severe limitation on agricultural use due to salinisation or alcalization and drainage problems. These lands are not arable currently. Special technical efforts and material may render them usable. They are located in valleys, in depressions, and on slopes characterized by Typic Endoaquepts, Typic Haplosalids, Aquic Natrustalfs, Lithic Haprendolls and Typic Udorthents. Class VI – non–feasible irrigation lands that are degraded or have a high degradation risk. They require severe limitations for arable use because they are thin, with skeletal character, and the terrain is irregular. These lands are found in the same areas mentioned above. They can be irrigated by minor rivers in the valley, in areas where hard rocks are present under the loess strata (Dobrogea). Soils in these areas are Lithic Ustorthents and Inceptisols.

Back to 3.0W Sustainable Soils and Life on Land - Poster
Back to WCSS

Back to The 18th World Congress of Soil Science (July 9-15, 2006)