Browsing by Author "Ors, Selda"

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Deficit Irrigation With Wastewater in Direct Sowed Silage Maize Reduces Co2 Emissions From Soil by Providing Carbon Savings
(Iwa Publishing, 2022) Yerli, Caner; Sahin, Ustun; Kiziloglu, Fatih Mehmet; Oztas, Taskin; Ors, Selda
Direct sowing and deficit irrigation practices can reduce the effect of wastewater on CO2 emissions from soil by providing carbon savings. Therefore, the effect of domestic recycled wastewater uses at different levels in irrigation under conventional tillage and direct sowing practices on the CO2 emission from soil at the end of the vegetation period of silage maize was investigated by comparing it with full irrigation of fresh water. Both organic carbon and CO2 emissions in the second year in fully irrigated treatments were higher than those in the first year. The CO2 emission in the full irrigation with wastewater (0.263 g m(-2) h(-1)), compared to full irrigation with fresh water and 33 and 67% deficit irrigations with wastewater, was higher at 23.4, 25.0, and 59.3%, respectively. Direct sowing practice also (0.193 g m(-2) h(-1)) resulted in 17.0% less CO2 emission as compared to conventional tillage. The positive linear relationships of H2O emission and the soil moisture content at different depths (5, 10, and 20 cm) with CO2 emission were significant, and the negative relationships with the soil temperatures were also found. It has been concluded that deficit irrigation and direct sowing applications can be practical for reducing CO2 emissions from soil in wastewater irrigation conditions.
Effects of Deficit Irrigation on Essential Oil Composition and Yield of Fennel (Foeniculum Vulgare Mill) in a High-Altitude Environment
(Taylor & Francis inc, 2018) Coban, Furkan; Ozer, Hakan; Ors, Selda; Sahin, Ustun; Yildiz, Gul; Cakmakci, Talip
Successful fennel (Foeniculum vulgare Mill) production in semi-arid environments depends largely on irrigation applications. Deficit irrigation studies on fennel are lacking or very limited, particularly in high-altitude environments. This study was conducted to determine the effects of deficit irrigation levels on the essential oil content, essential oil yield, and chemical composition of fennel. The experiment was carried out in 2014 and included four deficit irrigation levels: 100% (I-1), 80% (I-2), 60% (I-3), and 40% (I-4) of Class A pan evaporation. All parameters were significantly affected by deficit irrigation applications. Essential oil content tended to increase under increased water deficit conditions with the range of 2.21% to 2.42%. Anethole (90.71-91.62%) was the major compound in the fennel fruit oil, followed by estragole (3.60-4.02%), limonene (2.19-3.24%), and fenchone (0.96-1.55%), respectively. Essential oil yield showed an increase with increased irrigation amounts.
Fertility and Heavy Metal Pollution in Silage Maize Soil Irrigated With Different Levels of Recycled Wastewater Under Conventional and No-Tillage Practices
(Springer, 2025) Yerli, Caner; Sahin, Ustun; Oztas, Taskin; Ors, Selda
Irrigation with recycled domestic wastewater has been known to obtain positive effects on improving soil fertility, but it may also become a risk factor in case of causing an increase in soil salinity and/or heavy metal concentration of soil. No-tillage can retain soil moisture, helping to reduce irrigation water necessity, and thus lower amounts of heavy metals and salts are added to soil under wastewater irrigation conditions. The objective of this study was to analyze the effects of wastewater irrigation at different levels of on silage maize cultivation under conventional tillage and no-tillage conditions by comparing to full irrigation with fresh water. The two-year experiment was planned according to the split-plots design in the random blocks with three replications. The results indicated that full irrigation with wastewater increased soil salinity, organic matter content, total nitrogen, plant available phosphous, exchangeable cations, exchangeable sodium percentage and soil essential and non-essential heavy metal contents, but decreased soil pH and lime content. Increasing rates in organic matter content, total nitrogen, plant available phosphorus and exchangeable potassium were higher, but in electrical conductivity, and heavy metal accumulation were lower in soil under no-tillage as compared to conventional tillage. Contamination and enrichment factors and geographic accumulation index showed that non-essential heavy metal contamination due to cadmium and nickel, increased in full irrigation with wastewater. Irrigation with wastewater also increased heavy metal accumulation in silage maize. No-tillage can be a recommendable water management practice considering that the risks of soil salinity and heavy metal accumulation can be reduced and that soil fertility can be increased. Also, in reducing the risk of accumulation of cadmium and nickel in soil, 33% deficit irrigation with wastewater can make no-tillage more available.
Improvement of Water and Crop Productivity of Silage Maize by Irrigation With Different Levels of Recycled Wastewater Under Conventional and Zero Tillage Conditions
(Elsevier, 2023) Yerli, Caner; Sahin, Ustun; Ors, Selda; Kiziloglu, Fatih Mehmet
Although wastewater irrigation has a long history involving different stages of development, the future expec-tation to improve crop yield and water productivity in wastewater irrigation practices is still relevant. Therefore, the aim of this study is to evaluate water productivity, yield and crop quality of silage maize irrigated with different application levels (100%, 67%, and 33% of irrigation need) of recycled wastewater with three replicates in conventional tillage and zero tillage practices and comparing them with full fresh water irrigation. The results of two-year field studies showed that zero tillage resulted in saving 10.1% of irrigation water on average compared to conventional tillage and actual evapotranspiration in silage maize with zero tillage was 7.4% less. Biomass yield was the highest in full irrigation with wastewater under zero tillage. Zero tillage practice provided 12.0% and 13.2% higher water productivity(WP) and irrigation water productivity(WPirrig), respectively compared to conventional tillage. The WP was higher in treatments with wastewater with 100% and 67% irri-gation levels, while the WPirrig was higher in treatment with wastewater with 67% irrigation level. While the crop total soluble solids, nutrients, crude protein, chlorophyll(SPAD), leaf area index and leaf relative water content (LRWC) values were higher in full irrigation with wastewater, acid and neutral detergent fibers and membrane damage was lower. Crude protein in zero tillage was lower than in conventional tillage, while SPAD and LRWC were higher. It could be concluded that wastewater can increase silage maize biomass yield and crop quality. This result may be more valuable in terms of both protecting scarce fresh water resources and contributing to the environment with waste disposal. Moreover, 67% irrigation treatment with wastewater can be preferred for the higher WP and WPirrig values, and zero tillage can be used as a practical treatment that contributes to the yield and water saving.