Determination of salt leaching and gypsum requirements with field tests of saline–sodic soils in central Turkey

Abstract

This study was conducted to determine the best method for leaching salt from saline-sodic soils in central Anatolia in Turkey. The field experiment was set up in a randomized block with three replications. As reclamation material, mined gypsum was applied to the treatment plots in 0, 20, 40 and 60 t ha À1 dosages and 3.60 m leaching waters were applied to the plots. The infiltration capacities of the soil increased in proportion to the amount of gypsum applied. Leaching of 70% of the soluble salt from the soil profile required a depth of leaching water of approximately six times the soil depth to be reclaimed. Relationships between theoretically calculated and required actual gypsum could be described by exponential equations. Gypsum application showed a good response. It was concluded that gypsum or other reclamation materials have to be applied to reclaim sodic soils in the Eregli plain. Copyright RÉ SUMÉCette étude a été entreprise pour déterminer les meilleurs façons de lessiver le sel dans les salins-sodiques en Anatolie central en Turquie. L'expérience sur le terrain a été conduite sur un bloc randomisé avec trois répétitions. On a appliqué aux parcelles un amendement de gypse à la dose de 0, 20, 40 et 60 t ha À1 et un lessivage avec 3.6 m d'eau. Les capacités d'infiltration du sol ont augmenté proportionnellement à la quantité de gypse appliquée. Un lessivage de 70% du sel soluble dans le sol a exigé une lame d'eau d'approximativement six fois la profondeur de sol à traiter. Le rapport entre le gypse théoriquement calculé et réellement exigé peut être décrit par une exponentielle. L'application de gypse montrant une bonne réponse, on a conclu à la nécessaire application de gypse ou d'autres matériaux d'amendement pour améliorer les sols sodiques en plaine d'Eregli.

Leaching effect of rainfall on soil under four-year saline water irrigation

“…Since climate conditions kept dry, on March 20 a supplementary irrigation was performed with a water volume of 500 m 3 /ha. At the end of the irrigation period of the three years (August 2007(August , 2008(August , and 2009), after the rainy season (March 2008 and2009) and at wheat harvesting in the fourth year (June 2010), soil samples were taken from the surface to 0.10 m, from 0.10 to 0.20 m depth, and -when the soil was furrowed -in the middle of the furrow, mid-way of the ridge between two contiguous furrows and at an intermediate point.…”

“…The rainfall pattern during the period of the trial (January-July 2007, July 2010) is illustrated in Figure 1. The total amount of rainfall during the cropping cycle of maize and sunflower (May-August of 2007, 2008, and 2009) was equal to 120-65.4, and 130.2 mm, respectively, whereas during the rainy seasons after irrigation (October-March of 2007-2008, 2008-2009, and 2009-2010) it was respectively equal to 391.2-250.3, and 157.3 mm, with great differences from one year to the other. The monthly values recorded during the last period ranged from 8.0 mm to a maximum of about 9.1 mm.…”

“…Soil degradation is progressing so quickly that many countries will not be able to implement sustainable agriculture in the near future unless suitable strategies are applied (Bahçeci 2009). Impermeabilization, contamination, erosion, salinization, alkalinization, and loss of organic matter are critical issues that need to be addressed (Marandola & Coderoni 2013).…”

Reclamation of saline and saline-sodic soils using gypsum and leaching water

“…As a result of leaching application, the clay mineral swells quickly, the hydraulic conductivity drops and the macropores that constitute the main drainage path are destroyed. Gypsum application contributes to increase calcium concentration in leaching water thus reducing swelling, dispersion and clay migration, and favouring the reclamation of saline-sodic soils in few years' time (Bahçeci, 2009). Therefore for both soils that showed the lowest ECe values (6 dS m , without reaching the preestablished limit.…”

Tuzlu-Sodyumlu Helvacı Serisi Topraklarının Tuzluluk ve Sodyumluluk Belirteçlerinin Değişimi

“…Deneme sonunda yapılan analiz sonuçlarında, toprak kolonunda yüzeyden itibaren 40-80 cm arasında tuzların yığıldığı saptanmıştır. Bahçeci (2009), başlangıç yıkamasıyla birlikte tuzların üst topraktan aşağı doğru daha derinlere yıkandığını ve o katmanlarda biriktiğini saptamıştır. Yine Bahçeci ve Nacar (2009) tarafından kapalı drenaj sisteminin bulunduğu bir alanda yapılan bir başka çalışmada, yıkamalarla üst toprak katmanında (20 cm) başlangıçta 10.3 dS.m -1 olan tuzun, dönem sonunda 2.1 dS.m -1 'ye düştüğü; en etkili yıkamanın bu katmanda gerçekleştiği ve toprağın 160-200 cm derinliği için başlangıçta 10.1 dS.m -1 olan tuz derişiminin, 7.5 dS.m -1 kadar azaldığı rapor edilmiştir.…”