In this study, it was aimed to evaluate the effects of different lateral depths and irrigation treatments on the bioethanol yield and yield components of the sweet sorghum (Sorghum bicolor L.) in the subsurface drip irrigation method. The experiment was carried out in three replications in a randomized block trial design in 2020 and 2021 in Antalya, Turkey. In irrigation treatments, three different irrigation water levels in which 100%, 66% and 33% of the amount were applied as irrigation water (I1, I2, I3, respectively), when the cumulative reference crop evapotranspiration reached 25±5 mm and lateral depth combinations in which the laterals were placed at two different depths, 25 cm and 50 cm (D1 and D2, respectively) were used. At the end of both years, a statistical difference (p<0.01) was determined between the mean yield components (forage, hay, juice and sugar yield) of different irrigation water levels. As the applied irrigation water level increased, the yield components also increased. While the interaction of lateral depth and irrigation water level affected forage and hay yield in the second year, sugar and juice yield values in the first year. In this study, it was determined that the difference in the effects of the interaction between the years was due to the irregular temperature increases in the second year climate, and the lateral depth of 50 cm was more suitable in drier conditions. At the end of two years, the bioethanol yields and evapotranspiration (ET) obtained in D1 treatments at different irrigation levels varied between 440-2962 L ha-1 and 105.1-473.0 mm, respectively, while it varied between 440-3222 L ha-1 and 105.1-473.0 mm in D2 treatments, respectively. The highest bioethanol yield in the first year was obtained from D1I1, D2I2, D2I1 treatments, while in the second year, from D2I1 was obtained. Considering the I1 treatments, more evapotranspiration was realized in the D1 despite the same amount of irrigation water applied in both years. In addition, when the applications that were irrigated at the same amount at 25 and 50 cm lateral depths in both years were compared, it was determined that water productivity (WP) and irrigation water efficiency (IWP) values obtained at 50 cm lateral depth were higher, except for I3. In this study, it was determined that a lateral depth of 50 cm was more suitable for maximum bioethanol yield, especially in warmer climatic conditions. At the same time, I1 and I2 irrigation levels have been suggested, depending on climatic conditions.

Irrigation water use efficiency is an important issue for both agricultural production and optimization of water resources in arid and semi-arid regions where water resources are limited. Surface drip irrigation (DI) is used in most of these areas. However, subsurface drip irrigation (SDI) has become widespread in recent years. Therefore, the effects of SDI method on the plant and contributions on the water saving should be examined and compared with the DI method in different plant and climate conditions. The aim of this study was to compare the effects of surface drip (DI) and subsurface drip irrigation (SDI) methods on canopy temperature measured with infrared thermometer and to evaluate deficit irrigation effects on soybean grown at the Batı Akdeniz Agricultural Research Institute (BAARI), Antalya, Turkey in 2017. Methods and Results:The study was designed in a randomized complete block design to include two irrigation methods (surface drip (DI) and subsurface drip irrigation (SDI)) and four different irrigation treatments (0%, 60%, 80%, and 100%) in three replications. The canopy temperatures were measured by an infrared thermometer between 12:00 and 15:00 hours before and after irrigation. Conclusions: The results showed that the canopy temperatures of the plants irrigated with the SDI method throughout the season were up to 2.5°C lower than the DI method. Also, the yield values obtained from the SDI method (439.1 kg da -1 ) were statistically higher than DI method (395.2 kg da -1 ). When compared to the DI method, a water saving of approximately 78.3 mm was obtained in SDI method. Significance and Impact of the Study: It was determined that the canopy temperatures of soybean irrigated with SDI method were lower compared to the DI method. In addition, there was a high level of exponential relationship and negative correlation between canopy temperatures and yield, applied irrigation water and evapotranspiration in both irrigation methods.

Chlorophyll is a significant biochemical component and can be determined in the laboratory (destructive) and using various chlorophyll content measuring devices (non-destructive). In this study, destructive and non-destructive methods were used to determine chlorophyll content and compared in peanut (Arachis hypogaea cv. NC-7) grown under different soil texture and saline water applications. The experiment was carried out in a complete randomized block design in pots using two soil textures (clay-loam and sandy) and three irrigation water salinity (0.7, 2.1 and 3.3 dS m -1 ). While the chlorophyll contents (Chl-a , Chlb, Chl-a+b, Chl-a/b) were determined with the acetone extraction procedure, which is classified as destructive methods under laboratory conditions, the Chlorophyll Content Index (CCI) values were measured with the hand-held chlorophyll meter device (Apogee CCM-200), which is a non-destructive method. While irrigation water salinity decreased all types of chlorophyll contents (Chl-a, Chl-b, Chl-a+b) (mg cm -2 ), it did not cause a statistical difference in Chl-a/b. Linear and polynomial models were fitted between the different chlorophyll contents and the CCI values under different soil textures and saline water levels. Model performances were slightly better with the polynomial model compared to the linear model in all experimental treatments. Since the difference between model performances is small, it is recommended to use the linear model due to its ease of use. In addition, the total chlorophyll content can be safely estimated under saline conditions by using portable chlorophyll meters.