In this study, the effects of different organic matter additives [soil (control), 20 ton ha-1 farmyard manure, 20 ton ha-1 biochar, and 10 ton ha-1 farmyard manure+10 ton ha-1 biochar] to the soil of lettuce grown with different irrigation water levels [100% (full irrigation), 75% (25% deficit irrigation), 50% (50% deficit irrigation), and 25% (75% deficit irrigation)] on water and irrigation water productivity efficiencies and plant characteristics were investigated. Among the organic matter additives, the biochar reduced the amount of irrigation water and actual evapotranspiration of lettuce and increased its marketable yield, thus the highest water and irrigation water productivity efficiencies were obtained from biochar treatment. Despite the decreasing marketable yield in the 50% irrigation treatment, the proportionally decreasing amount of irrigation water and actual evapotranspiration caused the highest water and irrigation water productivity efficiencies to occur in the 50% irrigation treatment. While the root diameter, root fresh and dry weights, stem diameter and length, head fresh and dry weights, marketable leaf number and yield, chlorophyll, and leaf relative water content of lettuce decreased with decreasing irrigation water levels, root length and membrane damage increased. The effects of organic matter additives on all of these physical-physiological properties, except root diameter and membrane damage, were found to be significant, and the biochar provided the most effective development of these parameters under the deficit irrigation regime. Considering that the yield and yield characteristics in 75% irrigation treatment do not decrease at a very significant level compared to full irrigation (100%) and that these decreases can be compensated by biochar and that the farmyard manure+biochar as alternative treatment is also effective in improving the decrease in yield parameters, treatment of 10 ton ha-1 farmyard manure+10 ton ha-1 to the soil at 75% irrigation water level was found to be recommended in lettuce cultivation.

Increasing population and challenges among the sectors due to the climate change and incorrect water policy has increased the pressure on water resources. This situation being as a global crisis particularly in respect to the food security has accelerated productive utilization of water supplies. The aim of the current study with 2-year experiments was to identify the effect of different irrigation interval and irrigation regimes on the yield and yield components of dry bean having greater than 50% of total world legumes production. In that experiment, two different irrigation interval, 7 and 14-day, and three different irrigation levels, (I100, I75 and I50, were studied. In results, the maximum yield was obtained from 7-day irrigation interval, and 28% yield reduction was detected at 14-day irrigation interval. In examine the irrigation levels, the highest yield was found at full irrigation (I100), and increasing water stress caused significant yield reductions e.g. 21% and 49% for I75 and I50, respectively. The evapotranspiration and total applied water as an average of 2013-2014 were calculated as 533 mm, and 450 mm, respectively. In assessment of the both the combine year results, the ky value was determined as 1.59, and this finding shows that dry bean crop is sensitive to the water stress condition.

Increasing population and challenges among the sectors due to the climate change and incorrect water policy has increased the pressure on water resources. This situation being as a global crisis particularly in respect to the food security has accelerated productive utilization of water supplies. The aim of the current study with 2-year experiments was to identify the effect of different irrigation interval and irrigation regimes on the yield and yield components of dry bean having greater than 50% of total world legumes production. In that experiment, two different irrigation interval, 7 and 14-day, and three different irrigation levels, (I100, I75 and I50, were studied. In results, the maximum yield was obtained from 7-day irrigation interval, and 28% yield reduction was detected at 14-day irrigation interval. In examine the irrigation levels, the highest yield was found at full irrigation (I100), and increasing water stress caused significant yield reductions e.g. 21% and 49% for I75 and I50, respectively. The evapotranspiration and total applied water as an average of 2013-2014 were calculated as 533 mm, and 450 mm, respectively. In assessment of the both the combine year results, the ky value was determined as 1.59, and this finding shows that dry bean crop is sensitive to the water stress condition.

This trial was realized in the greenhouses of Uludağ University Yenişehir Vocational School between 2009 and 2010 to investigate effects of water deficit on yield and quality parameters of onion during four crop growth stages. In this trial, fourteen irrigation treatments in four growth periods (establishment, vegetative, yield formation and ripening) of onion (Allium cepa L E.T Grano.502) were constituted and the yield and quality parameters found from these treatments were evaluated. The layout of the experiment was a completely randomized block design with three replications for each of the fourteen irrigation treatments tested. According to the content of the treatments, the irrigation amount water applied to the plants varied between 0 and 436 mm in the first year, and between 0 and 448 mm in the second year. Water consumption of onion in the first year ranged between 205 and 496 mm and in the second year ranged between 210 and 502 mm. Yield, bulb weight, diameter, height and dry matter ratio were determined statistically significant. In 2009 and 2010 years, the maximum yield were found as 52.2 t ha-1 and 52.4 t ha-1 in E100V100Y100R100 treatments, while the minimum yield were found as 0.8 t ha-1 and 0.5 t ha-1 in the E0V0Y0R0 treatments, respectively. Water- yield relationship factors (ky) in 2009 and 2010 years were found as 1.03 and 1.04, respectively. The maximum WUE and IWUE values were obtained from establishment and ripening periods. Establishment and ripening periods may be suggested as the maximum efficient irrigation periods for the onion applied with drip irrigation under unheated greenhouse conditions.

The present study was carried out to investigate the effects of different water deficit levels applied through growing season on silage yield, quality and water use efficiency (WUE) of main crop silage maize under semi-arid climate conditions during the years 2014 and 2015. Irrigation treatments were set as 100% (I100), 70% (I70) and 35% (I35) supply of depleted water within 0-90 cm effective root zone in 7-day intervals. Applied irrigation water quantities in I100(control) treatment of the first and second year (in 8 irrigations) were respectively observed as 693 and 666 mm. Plant water consumptions in control treatment were respectively measured as 770 and 738 mm. Silage yield was 10650 kg da−1 in the first year and 10600 kg da−1 in the second year. The silage yield obtained from I70 treatment with 30% water deficit was statistically placed in group (B) following I100 (control) treatment. The water deficits over 30% resulted in significant decreases in silage yield and quality. The correlation coefficient between ETa and dry matter was respectively identified as (r: 0.78), (r: 0.87) in 2014 and 2015 and the correlation coefficient between plant water consumption (ETa) and protein content was respectively identified as (r:0.81), (r:0.80) and the correlations between ETa and quality parameters were found to be positive and highly significant. There were significant linear correlations between ETa and kernel yield (Y). Yield response factor (ky) of experimental years were respectively calculated as 0.74 and 1.06. Irrigation water use efficiency (IWUE) values varied between 3.80-5.10 kg da−1 mm and water use efficiency (WUE) values varied between 3.62 and 4.42 kg da−1 mm.

The present study was carried out to investigate the effects of different water deficit levels applied through growing season on silage yield, quality and water use efficiency (WUE) of main crop silage maize under semi-arid climate conditions during the years 2014 and 2015. Irrigation treatments were set as 100% (I100), 70% (I70) and 35% (I35) supply of depleted water within 0-90 cm effective root zone in 7-day intervals. Applied irrigation water quantities in I100(control) treatment of the first and second year (in 8 irrigations) were respectively observed as 693 and 666 mm. Plant water consumptions in control treatment were respectively measured as 770 and 738 mm. Silage yield was 10650 kg da−1 in the first year and 10600 kg da−1 in the second year. The silage yield obtained from I70 treatment with 30% water deficit was statistically placed in group (B) following I100 (control) treatment. The water deficits over 30% resulted in significant decreases in silage yield and quality. The correlation coefficient between ETa and dry matter was respectively identified as (r: 0.78), (r: 0.87) in 2014 and 2015 and the correlation coefficient between plant water consumption (ETa) and protein content was respectively identified as (r:0.81), (r:0.80) and the correlations between ETa and quality parameters were found to be positive and highly significant. There were significant linear correlations between ETa and kernel yield (Y). Yield response factor (ky) of experimental years were respectively calculated as 0.74 and 1.06. Irrigation water use efficiency (IWUE) values varied between 3.80-5.10 kg da−1 mm and water use efficiency (WUE) values varied between 3.62 and 4.42 kg da−1 mm.

The main purpose of this paper is to review on the effect of irrigation water quality and deficit irrigation on crop yield and water use efficiency. Low quality water for irrigation can impose a major environmental constraint to crop productivity. If salts become excessive, losses in yield will result. To prevent yield loss, salts in the soil must be controlled at a concentration below that which might affect yield. Irrigation application below the full evapotranspiration requirement is termed as deficit irrigation. Deficit irrigation consists of deliberately applying irrigation water in amounts below the plant’s water requirements. Deficit irrigation can be applied at certain periods during the crop’s growing season or throughout its growing season. Yield reductions also occur in a number of crops when subjected to water stress. Yield reductions depend on the crop’s sensitivity to water stress at its various growth stages. In order for deficit irrigation to be an economically viable practice, the revenue lost due to yield reduction should be lower than savings in total cost of production. The goal of deficit irrigation is to increase crop water use efficiency by reducing the amount of water that is applied or by reducing the number of irrigation events. The interaction effects of water quality and DI illustrated that when the two types of stresses; saline and DI were coupled together, a serious reduction occurred on total dry biomass and total yield. The interaction effects of water quality and deficit irrigation illustrated that when the two types of stresses; saline and deficit irrigation were coupled together, a serious reduction occurred on total dry biomass and total yields.

In this study, the effects of different organic matter additives [soil (control), 20 ton ha-1 farmyard manure, 20 ton ha-1 biochar, and 10 ton ha-1 farmyard manure+10 ton ha-1 biochar] to the soil of lettuce grown with different irrigation water levels [100% (full irrigation), 75% (25% deficit irrigation), 50% (50% deficit irrigation), and 25% (75% deficit irrigation)] on water and irrigation water productivity efficiencies and plant characteristics were investigated. Among the organic matter additives, the biochar reduced the amount of irrigation water and actual evapotranspiration of lettuce and increased its marketable yield, thus the highest water and irrigation water productivity efficiencies were obtained from biochar treatment. Despite the decreasing marketable yield in the 50% irrigation treatment, the proportionally decreasing amount of irrigation water and actual evapotranspiration caused the highest water and irrigation water productivity efficiencies to occur in the 50% irrigation treatment. While the root diameter, root fresh and dry weights, stem diameter and length, head fresh and dry weights, marketable leaf number and yield, chlorophyll, and leaf relative water content of lettuce decreased with decreasing irrigation water levels, root length and membrane damage increased. The effects of organic matter additives on all of these physical-physiological properties, except root diameter and membrane damage, were found to be significant, and the biochar provided the most effective development of these parameters under the deficit irrigation regime. Considering that the yield and yield characteristics in 75% irrigation treatment do not decrease at a very significant level compared to full irrigation (100%) and that these decreases can be compensated by biochar and that the farmyard manure+biochar as alternative treatment is also effective in improving the decrease in yield parameters, treatment of 10 ton ha-1 farmyard manure+10 ton ha-1 to the soil at 75% irrigation water level was found to be recommended in lettuce cultivation.