Effect Of Different Irrigation Levels Research Articles

Determination of the Effects of Different Irrigation Levels and Vermicompost Doses on Water Consumption and Yield of Greenhouse-Grown Tomato

This study was conducted in pots under a polycarbonate greenhouse to determine the effects of different irrigation levels and vermicompost doses on the morphological and phenological characteristics, water consumption, water use efficiency, and yield parameters of tomato plants. For this purpose, different irrigation levels of 100%, 75%, 50% (I100: full irrigation, I75, I50) and vermicompost (VC) doses of 0, 10% and 20% (VC0, VC10 and VC20, w/w) were applied as the treatments. The study’s results determined the irrigation levels and vermicompost doses affected the tomato plants’ morphological and fruit quality parameters. The highest and lowest plant water consumption (ET) values for the treatments were determined as 47.8 L (I100VC10) and 21.2 L (I50VC0), respectively. Moreover, irrigation water levels and vermicompost doses significantly influenced the total yield of tomatoes. The highest and lowest total and marketable yields were obtained from the I100VC20 and I50VC0 irrigation levels and vermicompost doses. Similarly, the highest and lowest total water use efficiencies were achieved from the I100VC20 (21.9 g L−1) and I50VC0 (11.0 g L−1) treatments. Furthermore, the highest and lowest marketable water use efficiencies were obtained from the I100VC20 (21.9 g L−1) and I50VC0 (7.8 g L−1) treatments. The yield response factor (ky) was found to be 1.42. Although the highest efficiency was achieved from 100% full irrigation and a 20% vermicompost dose in the study, it is suggested that 75% irrigation level and 10% fertilizer doses can also be applied in places where water is limited and fertilizer is expensive. The results revealed that the appropriate irrigation level and vermicompost doses could reliably be used to enhance tomato yield.

Water strategy improves the inflorescence primordia formation of 'Arra 15' grapevine in the Brazilian semiarid region

Failure in irrigation management of grapevines grown in the Brazilian semiarid region can affect bud fertility. Adequate irrigation, considering both the development of bunches in the current cycle and the formation of fertile buds for subsequent cycles, can bring significant advances to viticulture. Therefore, the objective of this research was to investigate the effect of different irrigation levels during flowering on the formation of buds and potential bunches of 'Arra 15' grapevine and its relationship with metabolic processes. A field experiment was carried out in a commercial vineyard in Petrolina, Pernambuco, Brazil, during the 2021 and 2022 seasons. The experiment was designed in randomized blocks with four replications and five irrigation levels (70; 85; 100; 115 and 130% of crop evapotranspiration – ETc) during three production cycles. The variables fertile bud, vegetative bud, dead bud, potential fertility of the basal, median, and apical regions of the branches, number of potential bunches, reducing sugar, total soluble sugar, net photosynthesis, stomatal conductance, transpiration, and relative chlorophyll index were evaluated. The 115% ETc irrigation level improved the number of fertile buds and number of potential bunches. Irrigation level above 115% ETc increased gas exchange and relative chlorophyll index, while 70% ETc increased leaf sugar content. The most appropriate irrigation strategy is the application of 115% ETc during the flowering stage, for the increase of fertile buds and potential bunches of the next cycle, without influencing the vine metabolism. Total soluble sugars are a promising indicator of water deficit during flowering and as an indicator of vegetative bud formation for the next cycle.

Water management, planting slope indicators, and economic benefit analysis for Panax notoginseng production decision under shaded and rain-shelter cultivation: A three-year sloping fields experiment

Panax notoginseng cultivation planting conditions are harsh and require high soil moisture and slope of cultivated land, plus it takes 3–7 years from planting to harvesting. At present, the continuous crop barrier of Panax notoginseng has not been solved, which makes the arable land suitable for planting significantly reduced. And yet, there is almost no report on the impact of coupling water and slope on the growth of Panax notoginseng. Therefore, this study aims to explore the effects of different irrigation levels and slopes on soil water content (SWC) in the root zone, soil nutrient content, root characteristics, yield, water use efficiency (WUE), partial fertilizer productivity (PFP) and economic benefits of Panax notoginseng. During 2018–2020, a field experiment was conducted in the Panax notoginseng growing seasons with three irrigation levels (I1: 70–75% θFC, I2: 75–80% θFC, I3: 80–85% θFC) and three slopes (S1: 2.43°, S2: 6.38°, S3: 16.38°). The results evidenced that soil water and nutrient content increased with increasing irrigation and decreased with increasing slope. The yield of Panax notoginseng, root morphological characteristics, WUE, PFP, and economic benefits showed a trend of increasing first and then decreasing with the increase of irrigation amount and slope, which increased with the increase of planting years. These parameters reached their maximum at the irrigation I2 (75–80% θFC) and slope S2 (6.38°) treatments. Thus, based on the results of this study, medium irrigation I2 (75–80% θFC) and slope S2 (6.38°) should be considered as the best slope and water management strategy to obtain both high Panax notoginseng yield and economic benefits. Through establishing a multi-objective optimization model with binary quadratic regression analysis. It was indicated that Panax notoginseng yield, WUE, PFP, and economic benefits simultaneously reached ≥ 98% of their maximum values when irrigation interval was 152–193 mm and slope interval was 5.4–9°. In summary, the results obtained in this study have important practical significance for the water management of Panax notoginseng cultivation in slope farmland in Yunnan Province, China.

Comparative effect of different irrigation levels and soil amendments on cabbage productivity in semi‐arid Central Namibia

AbstractIn semi‐arid Central Namibia, poor sandy soils limit sustainable crop production. We assessed cabbage performance in two split‐plot field experiments. In Experiment 1, treatments comprised two irrigation levels: full irrigation (watered 3 days a week) and reduced irrigation (watered 2 days a week) as the main plot factor and six soil amendments (biochar; compost; zeolite; nitrogen, phosphorus potassium [NPK]; Be‐Grow boost [L] hydrogel; and hoof and horn + bone [HHB] meal) as subplot factors in three replications. Full irrigation produced a significantly higher yield (21.1 t ha−1), head weight (0.958 kg) and larger head girths (42.1 cm). Biochar produced the highest marketable heads (24,884 heads ha−1), water use efficiency (76.0 kg ha−1 mm−1) and the largest head girths (42.7 cm). In Experiment 2, water was applied 5 and 4 days a week for full and reduced irrigation; the application rates of compost, HHB meal, Be‐Grow boost (L) hydrogel and NPK were modified. The interaction of Be‐Grow boost (L) hydrogel, NPK and biochar with full irrigation and HHB meal with reduced irrigation produced more marketable heads (28,935, 28,009, 27,546 and 28,703 heads ha−1, respectively). Therefore, full irrigation with these amendments could be used for resilient cabbage production in Central Namibia.

Effects of Post-Anthesis Irrigation on the Activity of Starch Synthesis-Related Enzymes and Wheat Grain Quality under Different Nitrogen Conditions.

To develop optimal management strategies for water and nitrogen fertilizer application in winter wheat cultivation, we conducted a potted experiment to investigate the effects of different irrigation levels and nitrogen fertilizer treatments on the activity of starch synthesis-related enzymes and the grain quality of winter wheat. The potted experiment consisted of three irrigation levels, with the lower limits set at 50-55% (I0), 60-65% (I1), and 70-75% (I2) of the field capacity. In addition, four levels of nitrogen fertilizer were applied, denoted as N0 (0 kg N hm-2), N1 (120 kg N hm-2), N2 (240 kg N hm-2), and N3 (300 kg N hm-2), respectively. The results revealed the significant impacts of irrigation and nitrogen treatments on the activities of key starch-related enzymes, including adenosine diphosphoglucose pyrophosphrylase (ADPG-PPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS), and starch branching enzymes (SBE) in wheat grains. These treatments also influenced the starch content, amylopectin content, and, ultimately, wheat yield. In summary, our findings suggest that maintaining irrigation at a lower limit of 60% to 65% of the field capacity and applying nitrogen fertilizer at a rate of 240 kg hm-2 is beneficial for achieving both high yield and high quality in winter wheat cultivation.

Drought resistance, quality characteristics and water‐yield relationships of some wheat (Triticum aestivum L.) lines and varieties

AbstractThe aim of this study was to determine the drought tolerance of four different genotypes, including two wheat varieties (Ceyhan 99 and Sagittario) and two wheat lines (Zdeb101 and Zdeb102), and create irrigation schedules. This study was performed with treatments applied at three irrigation levels (S100: treatment where the entire water need of the plant was met, S50: 50% of the water provided in the S100 treatment, S0: Rainfed), with four genotypes and four replications in a split‐plot design in Kahramanmaras East Mediterranean Transitional Zone Agricultural Research Institute in 2019 and 2020. The Ceyhan 99 and Sagittario varieties, which are widely cultivated in the region and the Zeb101 and Zdeb102 lines that are candidates for varieties were used in the study. In the study, 217.1 and 213.77 mm of water was given to S100, 108.54 and 106.88 mm of water was given to S50, and no irrigation was provided to S0 in 2019 and 2020, respectively. The effects of different irrigation levels on yield, water use efficiency (WUE), irrigation water use efficiency (IWUE), protein content and wet gluten content were investigated. At the end of this study, seasonal evapotranspiration (ET), irrigation water and yield decreased from S100 to S0. WUE, IWUE and yield response factor (Ky) values showed different trends in both years. There was no significant difference in yield between the varieties. However, in the stress susceptibility index (SSI) analyses of the genotypes, it was found that the most drought‐tolerant genotypes were Zdeb102 (0.50) and Ceyhan 99 (0.54). The highest protein content and wet gluten content were found as 11.38% and 22.24% in the Sagittario variety, respectively. It is recommended that Zdeb102 and Ceyhan 99 be cultivated in regions such as Kahramanmaras which have semi‐arid climate characteristics in the Mediterranean.

Effect of drip irrigation and organic mulches on growth, yield and water-use efficiency of French bean (Phaseolus vulgaris)

French bean (Phaseolus vulgaris L.) is an important crop for green and dry beans while tender pods as vegetable. An experiment was conducted during March–June 2021 at the research farm of Dr Y S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh to assess the effect of different irrigation levels and organic mulches on soil properties, growth and productivity of French bean. Experiment was laid out in Randomized Block Design with 3 replications comprising of 7 treatments. The study resulted, that plant height, no. of pods per plant, days to first harvest and yield of French bean were significantly affected by different irrigation levels and organic mulches. The maximum yield, water use efficiency, B:C ratio were observed under treatment I1M2 (80% ETc + Grass mulch). Therefore, adopting drip irrigation with mulching can contribute to increasing irrigated area and enhancing yield potential of French bean in the mid hill zone of Himachal Pradesh.

Effect of Different Irrigation Levels and Potato Hybrids on Yield and Nutrient Uptake of the Crop under Water Stress Conditions

As the scarcity of water increases, India will face the problem of decreasing annual freshwater use per capita. Healthy and sufficient crop and food production is essential for everyone due to the population increasing globally. Drought can result in severe productivity losses, especially for crops like the potato (Solanum tuberosum) that have shallow roots. In agriculture, it's critical to keep an eye on the soil, the climate, and the water supply for a crop. The study was carried out at the research farm of Vegetable Science, Chaudhary Charan Singh Haryana Agricultural University- Hisar, India during the rabi season of the year 2018-19. The field experiment was conducted in split plot design with four irrigation levels I1 (irrigation at 20mm CPE (Cumulative Pan Evaporimeter)), I2 (irrigation at 25mm CPE), I3 (irrigation at 30mm CPE) and I4 (irrigation at 30mm CPE + 5 t/ha grass mulch) and five potato hybrids V1 (P-21), V2 (P-32), V3 (P-37), V4 (P-38), V5 (Kufri Bahar) under two different crops at 60 and 75 days. The results revealed that parameters i.e., number of leaves, total tuber yield, and nitrogen uptake by crop were higher in both 60 and 75 days of crops under irrigation level 20 mm CPE (I1) and hybrid P-38 but in water stress condition I3 gives a better yield than other irrigation levels with hybrid -38. The present study opens up new doors to the farmers and researchers for sustainable production of potatoes.

Effect of Addition Nitrogen Fertilizer at Different Irrigation Levels on Saturated Hydraulic Conductivity by Using Two System of Irrigation

A field study was conducted in the province of Wasit - Kut, in a semi-arid region with a clay loam texture, for the purpose of studying the effect of adding nitrogen fertilizer, which included the level of 300 kg H-1 (N1) and 150 kg H-1 (N2) and the comparison treatment without adding fertilizer (N0) and using two levels of irrigation, which included EP (P1) 75%, EP (P2) 100% under drip irrigation (DI) and surface irrigation (SI) systems on saturated Hydraulic conductivity (Ks). The results showed that the addition of nitrogen fertilizer N1 had a significant effect by increasing the nitrogen availability using (DI), as the N1 gave the highest value of conductivity and a significant difference from the rest of the treatments, by increase 154.3% While the increase were 103.7% and 56.79% for the treatment N2 and N0, respectively. The results indicated that there were significant differences due to the effect of different irrigation levels on the Ks values, as P1 treatment gave the highest Ks value of 2.21 m day-1 compared with P2 treatment, which amounted to 1.94 m day-1, With the presence of significant differences for the two irrigation systems on the Ks values, as the values increased compared with the values before planting, with an increase of 129.6% and 38.27% for the (DI) and (SI) system. The study also showed that there were significant differences for the effect of the interaction between nitrogen fertilizer treatments and the irrigation levels, as well as the presence of significant differences for the effect of the interaction between the nitrogen fertilizer treatments and the irrigation system used on the Ks values.

Effects of different irrigation levels and varying doses of silicon applications on yield and some physiological parameters in lettuce cultivation

The study was repeated for two years to reduce the effects of water scarcity and drought stress in lettuce cultivation. The irrigation problem was created by applying 25% (I25), 50% (I50), 75% (I75) and 100% (I100) of the evaporation amounts formed in the class-A evaporation vessel. Si0 (0 kg ha–1), Si40 (40 kg ha–1), Si80 (80 kg ha–1) and Si120 (120 kg ha–1) silicon fertilisation was applied at four different doses. Head length, head diameter, head weight, root length, and leaf fresh and dry weight were measured in harvested plants. According to the data of 2020–2021, the best results in the effect of different doses of Si applications on plant head height, head diameter, head weight and root length at different irrigation levels were recorded from I75 × Si80, I75 × Si120, I100 × Si80, I100 × Si120 applications with the same severity level. While the Si40 dose gave good results at I75 and I100 irrigation levels, its effect decreased at I25 and I50 irrigation levels. At different irrigation levels where different doses of silicon were applied, I25 irrigation had the lowest leaf chlorophyll and relative moisture content and the most severe membrane damage, while I50 irrigation had a moderate effect. Leaf chlorophyll and moisture content increased, and membrane damage decreased in I75 × 80 kg ha–1 Si, I75 × 120 kg ha–1 Si, I100 × 80 kg ha–1 Si and I100 × 120 kg ha–1 Si applications. As a result, when the effects of the applications covering two years on plant growth and yield were evaluated, the most successful irrigation levels were determined as I75, I100, and the most successful silicon doses; were determined as 80 kg ha–1 and 120 kg ha–1.

Effect of Different Irrigation Levels and Mulching Methods on Performance of Organically Cultivated and Drip Irrigated Papaya

An experiment was conducted at research field of Deendayal Upadhyay Centre of Excellence for Organic Farming, CCS HAU, Hisar during the year 2021-22 to study the effect of different irrigation levels and mulching methods on performance of organically cultivated and drip irrigated papaya. The experiment comprised of nine treatments three different irrigation levels viz. 50%, 75% and 100% of crop water requirement and three mulching methods. The results showed that the plant height (238 cm), stem girth (45.93 cm), crown diameter (242.67 cm), number of fruits (42.33), yield per plant (53.80 kg) and total yield (134.50 t ha-1) were observed maximum for meeting 100% of crop water requirement with the application of straw mulch and minimum for meeting 50% of crop water requirement without mulch condition. The soil moisture was found maximum for meeting 100% of crop water requirement with the application of plastic mulch minimum for meeting 50 % of crop water requirement without mulch condition. From the results, it is also observed that the irrigation water use efficiency (59.02 kg m-3) was found maximum for meeting 50 % of crop water requirement with straw mulch and minimum (42.64 kg m-3) for meeting 100% of crop water requirement without mulch under drip irrigation system.

Effects of Different Irrigation Levels and Fertilizer Rates on Yield, Yield Components and Water Productivity of Onion at Adami Tulu Agricultural Research Center

Today’s agriculture sector faces a complex series of challenges to cope with the demands for sustainable management and production, which entails an increase in food production to ensure food security while using less water per unit of output and reducing nitrogen (N) fertilizer losses through leaching. The experiment was conducted at Adami Tulu Agricultural Research Center on-station to study the effect of different irrigation levels and N-fertilizer rates on plant height, bulb yield, bulb diameter, and bulb height and water productivity of onion. The treatments of the experiment had factorial combinations of three levels of watering and four N-fertilizer amounts. Results indicated that the highest plant height (53.07 cm), bulb height (6.13 cm), bulb diameter (6.21 cm), marketable bulb yield (241.39 qt/ha) and total bulb yield (252.89 qt/ha) were obtained from full irrigation and fully N-fertilized compared to the deficit conditions. The highest water productivity was recorded from 60% ETc irrigation level and 150 Kg/ha N-fertilizer application rate, but the reduction in water productivity with 80% ETc and 150 Kg/ha N-fertilizer application rate was not significant. Hence, if water is not limiting factor, 100% ETc irrigation level and 150 Kg/ha N-fertilizer could be suggested to apply. But if water becomes 232 limiting factor, 80% ETc irrigation level with 150 Kg/ha N-fertilizer would be more appropriate for growing onion in the study area. Therefore these can be used as one package of onion production technology and all growers better to apply.

Response of fruit yield, fruit quality, and water productivity to different irrigation levels for a microsprinkler-irrigated apple orchard (cv. Fuji) growing under Mediterranean conditions

Irrigation management strategies based on soil–plant–climate interactions are the key to improving water productivity and maintaining optimum yield and quality for apple orchards growing under Mediterranean conditions where water availability for irrigation is significantly decreasing. Thus, an experiment was carried out to investigate the effect of different irrigation levels on the yield, fruit quality, and water status of microsprinkler-irrigated apple trees (Malus domestica ‘Fuji’) located in a Mediterranean region in the central part of Chile. Four irrigation treatments were applied to a commercial orchard during the 2011/12 and 2013/14 growing seasons as follows: 125%, 100%, 75%, and 50% of actual evapotranspiration (ETa). Fruit yield (Y), crop load (fruits per tree, FP), fruit size (fruit weight (FW) and fruit diameter (FD)), fruit quality (firmness (FF), contents of soluble solids (SS), and starch (ST)), water productivity (WP), midday stem water potential (Ψstem), and water stress integral (WSI) were measured in each growing season. The results indicate that trees at 125% and 100% ETa reached an average Ψstem near − 1.0 MPa, whereas trees at 75% and 50% ETa reached Ψstem ∼ − 1.5 MPa. With the exception of FP, irrigation treatment had significant effects on Y, FW, FD, FF, SS, ST and WP. In this regard, the apple trees irrigated at 50% ETa produced fruits with the highest SS, FF, and WP, but the Y and fruit size (FW and FD) were significantly reduced because of severe water stress (average Ψstem ranged from −1.35 to −1.88 MPa). Apple trees with the 100% and 125% ETa treatments produced higher Y, FW, and FD than those with the 75% ETa treatment. In addition, the irrigation amount for apple trees irrigated at 125% ETa was 15% greater than for those irrigated at 100% ETa, but the yield and fruit quality were similar in both treatments. Finally, this study suggested that irrigation scheduling based on 100% ETa and Ψstem closed to − 1.5 MPa could be a suitable strategy for microsprinkler-irrigated apple (cv. Fuji) orchards growing in Mediterranean climate areas.

Responses of the Leaf Water Physiology and Yield of Grapevine via Different Irrigation Strategies in Extremely Arid Areas

The contradiction between water supply and demand has become increasingly prominent due to the large agricultural water consumption and low irrigation water use efficiency (IWUE) in the extremely arid area of Xinjiang, which needs to be solved by efficient irrigation. In this study, the effects of different irrigation levels (the lower and upper limits of irrigation (LULI) were 50–80%, 60–90%, and 70–100% of the field capacity (FC), respectively) under two irrigation methods (root zone irrigation (RZI) and furrow irrigation (FI)) on the photosynthetic physiology and yield of grape were analyzed to explore suitable irrigation schemes in extremely arid areas. The results show that the diurnal variation curve of the net photosynthetic rate (Pn) of grape leaves in the extreme arid region was not sensitive to the response of irrigation methods. However, RZI could improve the apparent quantum efficiency and maximum photosynthetic rate by 60.00% and 31.25%, respectively, reduce the light compensation point by 17.91%, and alleviate the photosynthetic lunch break phenomenon. Under FI, the physiological indexes of leaves increased with the increase in the LULI, while the Pn and SPAD values were the largest under RZI when the LULI was 60–90% of FC. The daily average Pn value of T2 in 2021 and 2022 ranged from 12.93 to 17.77 μmol·m−2·s−1. Compared with FI, RZI significantly improved the leaf water potential, Pn, and SPAD values by increasing the soil water content (SWC) of the 40–80 cm soil layer by 5.04–8.80%, which increased the yield by 6.86–18.67%. The results show that the yield and water use efficiency reached the peak when the LULI was 60–90% of FC under RZI, which could provide theoretical support for efficient irrigation of vineyards in extremely arid areas.

EFFECTS OF DIFFERENT IRRIGATION LEVELS AND NITROGEN DOSSES ON MINERAL CONTENTS OF MAIZE GRAINS

This study was conducted to determine the effects of different irrigation levels and nitrogen doses on macro and micronutrient contents of maize grains. Experiments were conducted with 3 different irrigation levels (100, 75 and 50% of field capacity) and 3 different nitrogen doses (100, 200 and 300 kg ha-1). Experiments were conducted in summer-growing seasons of the years 2013-2014 in split plots experimental design with 3 replications (irrigation levels on main plots and nitrogen doses on sub-plots). Grain N, P, B, Na, Fe, Mn, Zn and Mg contents increased and K, Ca, S, and Cu, contents decreased with increasing irrigation levels. Grain N, P, S, Cu, Fe and Mn contents increased. Grain K, Ca, and Mg contents initially increased and then decreased later on with increasing nitrogen doses. Nitrogen treatments were found to be as much effective as irrigation levels on grain mineral contents. Supportive treatments (irrigation, nitrogen) are recommended to eliminate mineral deficiencies in maize culture of the regions with water stress conditions.

Effect of deficit irrigation practices on greenhouse gas emissions in drip irrigation

One of the most important sources of greenhouse gas emissions resulting from human activities is agricultural activities. Many factors such as tillage, fertilizer use, irrigation, soil properties, etc. can affect greenhouse gas emissions. However, their effects on greenhouse gas emissions are still among the important research topics today. In this study, the effects of different irrigation levels on CO2, CH4, N2O emission in soil were investigated in silage maize irrigated with drip irrigation system. The study was carried out for two years, 4 different irrigation levels (S1:100%, S2:70%, S3:40%, S4:0) were applied. ADA 9516 silage mazie variety was used as the test plant. Static cylinders were used in each plot for greenhouse gas measurements. Greenhouse gas Cylinders (cells) consisting of 2 pieces made of PVC placed on trial plots were used in the research. Gas samples were analyzed with gas chromatograph (Agilent GC 7890A) and gas emission values of CO2, CH4 and N2O were calculated. In the study, the highest cumulative CO2 emission values by years were obtained for S1 with 1470.4 and 1129.6 kg ha−1, respectively (p<0.01) and the CO2 emission values measured after irrigation were found to be higher than the pre-irrigation emission values. The highest cumulative N2O emission values were obtained for S1 with 0.54 and 0.50 kg ha−1, respectively, over the years (p<0.001), N2O emission values were higher after irrigation. In CH4 analyzes, it was determined that the trial area soil behaved as a CH4 sink. The highest cumulative CH4 uptake in both years of the study occurred in S1 with -1.79 and -3.17 kg ha−1, respectively (p<0.01). Similarity was observed in CH4 flux values before and after irrigation. In the research, it was determined that irrigation practices increased greenhouse gas emission statistically. On the other hand, it has been determined that producing with irrigation using less agricultural land can help reduce greenhouse gas emissions.

Optimisation of irrigation strategy in sugar beet farming based on yield, quality and water productivity

Present experiments were conducted to determine the effects of different irrigation levels on yield, yield components and quality of drip-irrigated sugar beet under sub-humid conditions. Field experiments were conducted in the 2019 and 2021 growing seasons in the Bursa province of Turkey. Experiments were carried out in completely randomised blocks design with three replications. Irrigations were scheduled based on the replenishment of 100 (S1), 66 (S2), 33 (S3), and 0% (S4) of soil water depletion within the soil profile of 90 cm using 7-day irrigation intervals. In 2019, root yields varied between 29.32 (S4)–86.31 (S1) t/ha and sugar yields between 6.33–13.57 t/ha. In 2021, root yields varied between 26.18 (S4)–74.56 (S1) t/ha and sugar yields between 6.56–12.53 t/ha. Effects of different irrigation levels on investigated parameters were found to be significant (P &amp;lt; 0.01). The crop water consumption values were significantly related to root and sugar yields (P &amp;lt; 0.01). Based on present findings, S1 treatment was recommended to get the highest root and sugar yields. In case of limited water resources, S2 (33% water shortage) treatment with the highest water productivity and irrigation water productivity values could be recommended to ensure maximum efficiency from the applied irrigation water quantity.

Ertragskomponenten und Wasserstressindex von Mungbohnen bei Defizitbewässerung

This study was conducted in 2018 growing season to determine the response of mung bean to water stress. Effects of different irrigation levels on mung bean yield and yield components and potential use of crop water stress index (CWSI) in mung bean irrigation scheduling were also investigated. Five different irrigation levels (I100, I75, I50, I25 and I0) were applied through drip irrigation system. Amount of irrigation water supplied varied between 20–445 mm. Plant water consumption (ET) values varied between 125–521 mm. The highest yield (163 kg/da) was obtained from full-irrigation (I100) and the lowest yield (39.7 kg/da) was obtained from rain-fed (I0) treatment without irrigations. Plant heights varied between 58.6–21.2 cm, the first pod heights between 17.4–29.3 cm, number of branches per plant between 1.00–2.77 and number of pods per plant between 3.2–18.9. Water use efficiency (WUE) values varied between 0.31–0.50 kg/m3 and irrigation water usage efficiency (IWUE) values varied between 0.37–0.77 kg/m3. Crop water stress index (CWSI) values varied between 0.13–0.93. The lower limit (LL) equation was obtained as Tc-Ta = −2.9674 × VPD + 4.1341 (R2 = 0.66) and the upper limit (UL) was identified as 9.7 °C. Highly significant (p < 0.01) correlations were seen between CWSI and yield. Based on present findings, I75 was recommended under water deficit conditions. CWSI values of between 0.13–0.22 can be used to initiate irrigations for drip-irrigated mung bean.

EFFECT OF DIFFERENT IRRIGATION LEVELS ON BLACK CUMIN SEED YIELD, FIXED AND ESSENTIAL OIL CONTENTS IN SOUTHERN TURKEY

Limited information is available on irrigation practices of black cumin. This study aimed to evaluate the effect of different irrigation levels on seed yield, fixed oil content, and essential oil content and composition. The experiment was carried out for one crop season. The trial was arranged based on a randomized complete block design, with five treatments and four replications. Seed yield, fixed oil and essential oil contents were significantly affected by the different treatments. It can be concluded that supplying quantities of water below black cumin’s water requirement does not adversely affect its seed yield and oils content.

The Effects of Different Irrigation Levels and Nitrogen Doses on Growth, Quality and Physiological Parameters of Warm-Season Turfgrasses

This research was conducted to determine to effects of different irrigation levels and nitrogen doses on the various warm-season turfgrasses at DELETED by JAS for two years in a row. The experimental design was the randomized blocks in a split-split plot design with three replications. The main plot was irrigation levels (I1=25%, I2=50%, I3=75%, and I4=100% of pan evaporation), subplots were turfgrass species [hybrid Bermudagrass (Cynodon transvaalensis x Cynodon dactylon) cv. Tifdwarf, seashore paspalum (Paspalum vaginatum Sw.) cv. Seaspray, zoysiagrass (Zoysia japonica Steud.) cv. Zenit], and sub subplots were nitrogen doses (monthly 0.0, 1.25, 2.5, and 5.0 g N m-²). Visual turfgrass color and quality, clipping yield, leaf relative water content, loss of turgidity, chlorophyll content, and electrolyte leakage were measured. According to the results, significant differences were determined among irrigation levels, turfgrass species, and nitrogen doses for color, quality, clipping yield and physiological parameters. Turfgrass visual color, quality and clipping yield were shown to decrease significantly with decreases in irrigation water and N fertilizer. The study findings demonstrated that under a non-limiting water supply, irrigation could be decreased by adjusting N fertilizer rates with I3N3 treatments can maintain acceptable turfgrass visual color and quality under Mediterranean climatic conditions. In addition, at 25%(I1) deficit irrigation level, leaf relative water content, chlorophyll content decreased significantly, while an increase was determined in loss of turgidity. This research indicated that under 75%(I3) deficit irrigation and N3 nitrogen dose, acceptable quality can be maintained with ‘Seaspray’ seashore paspalum under Mediterranean climate performed.