Abdurrahman Hanay

Reclamation of Saline-Sodic Soils with Gypsum and MSW Compost

The effectiveness of sequential application of gypsum followed by matured mixed municipal solid waste (MSW) compost was investigated for the reclamation of saline-sodic soils. Soil plots were treated with 50 dt/ha (dry tone/hectare) of gypsum, followed by the addition of matured MSW compost at the 50, 100, and 150 dt/ha with five replications for each treatment. A number of physical, chemical and biological properties were investigated. The results from different treatments were compared with the Tukey-Kramer method. The results of this study show that the sequential application of gypsum followed by matured MSW compost can effectively restore degraded soils suffering from high soluble salts and exchangeable sodium content.

Decrease in Hydraulic Conductivity of Clay Soils with Salinity-Sodicity Problems due to Freezing and Thawing Effect

Freezing and thawing effects on soil structure are an important dynamic property of a soil. Consecutive freeze-thaw cycles in soil may affect aggregation either positively or negatively. Therefore, pore size distribution, hydraulic conductivity, infiltration rate and vulnerability of soil are also affected by freezing and thawing processes (Lehrsch et al., 1991). Radke & Berry (1998) determined a decrease in bulk density after freezing in soils which have a high value of bulk density at the start. Ice crystals forming within pores during freezing widen the diameter of the pores and thus decrease the bulk density (Kay et al., 1985). Aggregate stability is affected by freezing rate, soil moisture content at the time of freezing, and number of freeze-thaw cycles (Benoit, 1973; Edwards, 1991). Oztas & Fayetorbay (2003) found that aggregate stability generally increased when the number of freezing and thawing cycles increased from 3 to 6, but decreased after that point. Thus, freeze-thaw cycles may have negative or positive effects on soil structure. The determination of effects of freeze-thaw cycles in saline-sodic soils on the hydraulic conductivity is of importance for soil management and reclamation. Therefore, this study investigated the effect of freeze-thaw cycles on the hydraulic conductivity in soils. Materials and methods

DRENAJDA KAPLAMA MALZEMESİ OLARAK HAFİF A.GREGANIN KULLANIMI / USE OF LIGHTYVEIGHT AGGREGATE AS FILTER MATERIAL IN DRAINAGE

OZET: Dren borulari icerisinde samanla biriken sediment borular in islevini azaltmakta halta sistemi calisamaz duruma getirebilmekledir. Kullanilacak kaplama malzemesiyle drenlere sediment girisi azaltilarak sistemin daha etkin calismasi ve kullanim omrunun daha uzun olmasi saglanabilir. Kaplama malzemesi drenlere sediment girisini azaltirken su girisini engellememeli halta artirmalidir. Laboratuvar kofullarinda model dren tanklarinda yurutulen bu calismada; kaplama malzemesi olarak kum-cakil ve hafif agrega kullanilmistir. Hafif agrega ve kum-cakil malzemenin dren akisi ve sediment birikimi uzerine etkileri karsilastirmali olarak incelenmistir. Hafif agrega dren akisi yonunden kum-cakil malzemeden az etkili fakat sedimentin drenlere girisini onlemede ise kum-cakil malzemeden daha etkili olmustur. USE OF LIGHTYVEIGHT AGGREGATE AS FILTER MATERIAL IN DRAINAGE SUMMARY: Sediment accumulated in drain tubes day by day decreases functioning the syslemand sometimes ihe system might not work, By decreasing sedirnent intake with the aid offilter material the system works mor e effective and the life of system increases. Filler material musi not prevent water intake but must increase sediment intake. This study >V£LI conducted under laboratory conditions in the modelled drain boxes, and lightweight aggregate and sand-gravel were used as filter material. The effects of lightweight aggregate and sand-gravel material on drain flow and sedimentation were investigated. The effect of lightweighl aggregate on drain flovj smaller ihan that of sand-gravel material. In respect to preventing the sediment intake irtlo drain tubes sand-material was more effective.