Effects Of Irrigation Water Salinity Research Articles

Yield and Bio-Chemical Parameters of Onion (Allium Cepa L.) and Consequences of Saline Irrigation Water on It

At Department of Agricultural Chemistry and Soil Science a pot experiment was conducted during the rabi, season of 2017-18. Department of Agricultural Chemistry and Soil Science situated at College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat. The objective of the study is to assess the consequences of saline irrigation water on yield of Onion (Allium Cepa L.) varieties. The study also possess the growth and nutrients composition of Onion (Allium Cepa L.) varieties and effect of saline irrigation water on it. Four levels of salinity are contained viz., < 2.0, 4.0, 6.0 and 8.0 dS m-1. GJWO-3, GJRO-11, Talaj red, Pilli patti and PWF-131 these five varieties comprised in factorial completely randomized design with three replications. It found that the yield of chlorophyll a (5.77 mg/gf.wt), chlorophyll-b (4.22 mg/gf.wt), and total chlorophyll were significantly influenced by different levels of salinity, whereas; yield of fresh straw (37.03 g/pot), bulb (37.49 g/pot), RWC, proline (0.96 µmole/gf.wt), were significantly influenced among different varieties of onion tested.

Effects of Biochar and Municipal Solid Waste Compost on Soil Physical Quality and Productivity Index Under Sorghum Cultivation Irrigated with Saline Water

ABSTRACT Amending soil with different materials is gaining acceptance as an effective and inexpensive technique for reclamation of salt-affected soils. The main idea of this study was to investigate the effects of biochar, compost of municipal solid waste and different water salinities level on soil physical quality (SDexter) and soil productivity index (SPI). The treatments were as followed: Control: Soil without biochar or compost and irrigated with tap water, S1: Soil without biochar or compost and irrigated with saline water (EC = 4.5 dS m−1), S2: Soil without biochar or compost and irrigated with saline water (EC = 9 dS m−1), B: Soil amended with 1.5%w/w biochar and irrigated with tap water, B+S1: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 4.5 dS m−1), B+S2: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 9 dS m−1), C: Soil amended with 1.5%w/w compost and irrigated with tap water, C+S1: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 4.5 dS m−1), C+S2: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 9 dS m−1). Soil water characteristic curve (SWCC), Field capacity (FC), Plant wilting point (PWP), Plant available water (PAW), Dexter’s index of soil physical quality (SDexter) and SPI were examined in a greenhouse experiment. The SPI was calculated by integrating the effects of six soil quality indices: plant available water, organic matter (OM), Electrical conductivity (EC), pH, Bulk density (BD) and Root weighting factor (RF) for all treatments were calculated. The results showed that the B treatment had a slightly higher effect on SWCC. The applied B and C treatments caused insignificant increase in PAW relative to the control. In addition, application of biochar or compost to soil significantly increased the SDexter. The application of C treatment had insignificantly higher value of SDexter compared to other treatments. Compared with the control, SPI was significantly higher for the B and C treatments. Overall, the application of biochar/compost minimized the destructive effects of saline irrigation water and improved the quality of the salt-affected fine-textured soil.

Effect of irrigation water salinity on morphological and physiological characteristics of celery

The objective of this study was to investigate the effects of salinity levels of irrigation water on the morphological and physiological characteristics of celery (Apium graveolens L.) during early seedling development. Celery seedlings of Balena cultivar were grown with saline irrigation water consisting of different NaCl levels (0, 50, 100, 150, 200, 250, and 300 mM). The results showed that increasing salt stress inhibited plant growth by destroying physiological parameters. Each increase in NaCl resulted in a decrease in the length, diameter, number, and fresh and dry weight of leaves. Dry matter, chlorophyll content, leaf temperature, and turgor loss improved when NaCl levels were increased; however, salinity caused a reduction in leaf relative water content. Leaf fresh and dry weights were lower under salt stress, even at 50 mM NaCl. Leaf temperature was higher in plants grown under salinity and reached the maximum level at 100 mM NaCl. The stomata on the abaxial side of the leaves were smaller but more numerous under salinity than in the control plants. It was concluded that celery’s plant growth was significantly influenced by salinity and that it could endure salinity lower than 100 mM NaCl.

Integrated effect of saline water irrigation and phosphorus fertilization practices on wheat (Triticum aestivum) growth, productivity, nutrient content and soil proprieties under dryland farming

Wheat (Triticum aestivum) is the most common and oldest crop in Morocco and MENA region countries, cultivated both for human and animal nutrition. In Morocco, the irrigated perimeter of Tadla is the major wheat growing area affected by soil and groundwater salinity problematic. Previous studies have shown that phosphorus (P) fertilization can mitigate the negative effects of salinity on different crops. Thus, field experiments from the combination of four levels of irrigation water salinity and three P-fertilization rates were conducted during two successive growing seasons (between 2019 and 2021) at the National Institute of Agronomic Research (INRA), Tadla, Morocco. Our main objective was evaluating the potential of P-fertilization to improve wheat growth, productivity and quality under saline water irrigation practices. The crop simulation model APSIM, was also tested to assess its performance in simulating wheat growth, productivity, phosphorus and nitrogen nutrient dynamics in soil-plant system under saline conditions. Results showed that appropriate P-fertilization under saline conditions contributed to minimize the effect of salinity and improved wheat growth and production. Also, it was found that increasing P-fertilization improved nutrient uptake, and consequently the plant nutrient content. A good agreement between the measured and APSIM model simulated growth and yield state variables, as well as the plant and soil-N content. However, a model uncertainty and relevant limitations in simulating plant- and soil-P content output were identified and discussed. Overall, our finding suggests that appropriate P-application minimizes the adverse effects of high soil salinity and can be adopted as a coping strategy in wheat cultivation under saline water irrigation practices.

The Effects of Irrigation Water Salinity on the Synthesis of Photosynthetic Pigments, Gas Exchange, and Photochemical Efficiency of Sour Passion Fruit Genotypes.

The objective of this study was to evaluate the synthesis of photosynthetic pigments, gas exchange, and photochemical efficiency of sour passion fruit genotypes irrigated with saline water under the conditions of the semi-arid region of Paraíba state, Brazil. The experiment was conducted at the experimental farm in São Domingos, PB. A randomized block design was adopted, in a 5 × 3 factorial scheme, with five levels of electrical conductivity of irrigation water-ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1)-and three genotypes of sour passion fruit (Gigante Amarelo-'BRS GA1'; Sol do Cerrado-'BRS SC1'; and Catarina-'SCS 437'. The increase in the electrical conductivity of irrigation water negatively affected most of the physiological characteristics of the sour passion fruit at 154 days after transplanting. Significant differences were observed between sour passion fruit genotypes when its tolerance was subjected to the salinity of irrigation water. There was an increase in the percentage of damage to the cell membrane with the increase in the electrical conductivity of irrigation water, with maximum values of 70.63, 60.86, and 80.35% for the genotypes 'BRS GA1', 'BRS SC1', and SCS 437', respectively, when irrigated with water of 3.5 dS m-1. The genotype 'BRS Sol do Cerrado' showed an increase in the synthesis of photosynthetic pigments when irrigated with water of 3.5 dS m-1, with maximum values estimated at 1439.23 μg mL-1 (Chl a); 290.96 μg mL-1 (Chl b); 1730.19 μg mL-1 (Chl t); and 365.84 μg mL-1 (carotenoids). An increase in photosynthetic efficiency parameters (F0, Fm, and Fv) of the genotype 'BRS Gigante Amarelo' was observed when cultivated with water with high electrical conductivity (3.5 dS m-1).

Acceptable Salinity Level for Saline Water Irrigation of Tall Wheatgrass in Edaphoclimatic Scenarios of the Coastal Saline–Alkaline Land around Bohai Sea

Saline water irrigation contributes significantly to forage yield. However, the acceptable salinity levels for saline water irrigation of tall wheatgrass remains unclear. In this study, field supplemental irrigations of transplanted-tall wheatgrass with saline drainage waters having salinities of electrical conductivity (ECw) = 2.45, 4.36, 4.42, and 5.42 dS m−1 were conducted to evaluate the effects of saline water irrigation on forage yield and soil salinization. In addition, the effects of plastic film mulching, fertilization, and saline water irrigation on sward establishment of seed-propagated tall wheatgrass were determined. Finally, a pot experiment was carried out to confirm the above field results. The results showed that two irrigations with ECw = 2.45 and 4.36 dS m−1 saline waters produced the highest dry matter yield, followed by one irrigation with ECw = 4.42 or 5.42 dS m−1. After rainfall leaching, the soil EC1:5 was reduced by 41.7–79.3% for the saline water irrigation treatments. In combination with saline water irrigation, plastic film mulching promoted sward establishment and enhanced the plant height and dry matter yield of seed-propagated tall wheatgrass, while fertilization played a marginal role. However, two irrigations with ECw = 7.13 and 4.36 dS m−1 saline waters resulted in rates of 3.2% and 16.0% of dead plants under the mulching and no mulching conditions, respectively. Furthermore, a pot experiment demonstrated that irrigation with ECw = 5.79 dS m−1 saline water led to the lowest reduction in forage yield and the highest crude protein content in leaves. However, the plants irrigated with ECw ≥ 6.31 dS m−1 saline water enhanced soil salinity and reduced the plant height, leaf size, and gas exchange rate. Conclusively, one irrigation with ECw ≤ 5.42 dS m−1 and SAR ≤ 36.31 saline water at the end of April or early May could be acceptable for tall wheatgrass production and minimize the soil salinization risk in the coastal saline–alkaline land around the Bohai Sea.

The Effect of Irrigation Water Salinity, Organic Matter, and Zinc Nano-Fertilizer on the Productivity of Sunflower (Helianthus annuus L.)

In accordance with the randomized full block design, In the Al-Mahaweel district, Al-Imam hand, and Al-Birawi region, a field experiment was conducted in a soil with a texture of silty clay loam categorized as the primary typic torrifluvent group (RCBD), Examining the effects of irrigation water quality, organic matter, the amount of zinc nano-fertilizer sprayed on the plant, and the interaction of the research components on sunflower crop production using a split plot experiment with three replications, Three separate factors were used in the experiment: irrigation with four various amounts of organic fertilizer (zero), 20 tons/ha of cow and sheep dung, and three different concentrations of zinc nanofertilizer (0, 1.5, and 3 g). Organic matter significantly improved the yield characteristics of sunflowers, such as disc diameter, number of seeds per disc, weight of 500 seeds, and overall yield, as compared to spraying with nano-Zinc. The three elements’ interplay significantly affected sunflower productivity. On March 5, 2022, the seeds were sown using cork dishes and a midwife-led method. The seeds were luleo varieties from a French breeder. The midwives were transferred to the permanent location after 30 days. The findings showed that increasing the salt content of the irrigation water significantly decreased the values of disc diameter, number of seeds per disc, weight of 500 seeds, and overall yield of sunflower plants.

Comparative Study of the Impact of Saline Water Irrigation on Tomato Yield, Quality and Growth in Andhra Pradesh, India

Tomato (Lycopersicon esculentum Mill.) belonging to the family Solanaceae, is one of the most important, popular, nutritious, and palatable vegetables grown in Andhra Pradesh. It plays a vital role in providing a remarkable quantity of vitamin-A and vitamin-C in human diet. Tomato is cultivated all over Andhra Pradesh due to its adaptability to wide range of soil and climate. Saline water resources are abundant in the most areas of India. Most of these resources still have not been effectively utilized. The present investigation was conducted on the effects of saline water irrigation on tomato yield, quality and growth at the Research Farm, Department of Agricultural Engineering, Aditya Engineering College, Surampalem, East Godavari district, Andhra Pradesh. Saline water differing in Electrical Conductivity (EC) 6ds/m and 4ds/m was supplied to the plant after the seedlings. The objective of this work is to compare the effect of tomato crop under drip irrigation by three different treatments. First treatment is of fresh water under drip irrigation. Second treatment is of Nacl+water with an EC of 6ds/m under controlled irrigation in the ratio 2.5:7.5. Third treatment is of Nacl+water with an EC of 4ds/m under controlled irrigation in the ratio 1.5:8.5 of the tomato variety Pusa F1 hybrid is used for the experiment. Growth of crop includes plant height, number of fruits, number of leaves, fruit length, fruit diameter and fruit weight. The healthy growth that is 69.4cm plant height, 26 leaves per plant, 34 fruits per plant, 7.8 cm fruit length, 5.4 cm diameter of fruit and 89.4 g of average fruit weight and maximum score (4.86 out of 5) in organoleptic test were obtained in (T-1) i. e. drip irrigation. Although salinized tomato fruits were smaller than non-salinized control fruits, they have increased soluble solids, high sugar content, which all are highly requested qualities by the processing tomato industry. Current research concludes that the fresh water irrigation T-1 recorded the high-water use efficiency and saline water irrigation treatments (T2&T3) having less water use efficiency may be due to the plants suffering with more soil moisture stress due to osmotic pressure build up by the saline water irrigation.

An Incubation Experiment on Screening of Black Gram Varieties for Tolerance to Saline Irrigation Water

Water is a second most important resource in agriculture followed by land. The water availability for irrigation is often scarce, is one of the most critical input for agriculture production in most areas. Productivity in these areas can be enhanced by better management of rainwater and /or development of groundwater. So the present investigation was carried out to study the effect of saline water irrigation on the growth of blackgram. The various treatment included in the study were three ruling varieties of blackgram as factor V viz., V1- VBN 6, V2- VBN 4 and V3- VBN 3 and four salinity levels as factor S viz., S1-EC-3 dS m-1 and Sodium Absorption Ratio (SAR) - 4; S2-EC- 3 dS m-1 and SAR-6; S3-EC-3 dS m-1 and SAR-8; S4-EC-6 dS m-1 and SAR-6. The experiment was laid out in a Factorial Completely Randomized Design (FCRD) with three replications. The results of the study concluded that the soil application of saline water (EC-3 dS m-1 and SAR-4) irrigation to saline tolerant blackgram variety VBN 3 (S1V3) was identified as best treatment combination to realize the maximum germination of blackgram under saline water irrigation.

Effect of Application Different Combinations of Phosphogypsum and Humic Acids Mixed With Saline Irrigation Water on Broccoli Yield and NPK Concentration

Long-term irrigation with saline water causes detrimental effects on the soil-crop system. The study aimed to determine the best combination of Phosphogypsum and humic acid can mitigate the negative effects of saline water irrigation on broccoli growth. Therefore, two-factorial field experiment was conducted according to a randomized complete block design with three replications during autumn season of 2021 in Fallujah district /Anbar governorate in sandy loam soil. The first factor included three levels of saline water irrigation, namely 2.5, 5.0 and 7.0 dS.m-1. while the second factor involved three levels of humic acids i.e., 0.0, 0.25 and 0.50 g/l mixed with three levels of phosphogypsum that is 0.0, 0.25 and 0.50 g/l. Fruits weight, height, yield, plant nitrogen content, plant phosphorus, and plant potassium content were measured. The results showed that the combinations under study ( humic acids and phosphogypsum) had a crucial role in reducing the negative effects of irrigation salinity. Moreover, the macronutrients availability increased with increasing humic acids concentration in irrigation water. The observed results show a significant increase in the weight of broccoli fruit and yield at T8 by giving 325 g. plant-1and 8.66 t.h-1 respectively under effect of the combination under study. Also, the studied combinations led to increase the N,P,and K concentration in plant tissues. Where the highest observed averages of nitrogen and potassium were 3.96% and 2.56% at T8 treatment. While The highest concentration of phosphorus was observed at treatment T9 reached 0.47%.

CHERRY TOMATO CULTIVATION UNDER DIFFERENT LEVELS OF IRRIGATION WATER SALINITY AND ROOT MANAGEMENT SYSTEM

The use of saline water is a challenge of modern agriculture since the use of this type water reduces crop quality and yield. From this perspective, this study aimed to analyze the performance of cherry tomato under different levels of irrigation water salinity and partial root-zone irrigation. The experiment was conducted in a plant nursery at the Engineering and Agricultural Sciences Campus of the Federal University of Alagoas, in Rio Largo, Alagoas, Brazil. The experimental design was completely randomized, in a 4 x 2 factorial arrangement corresponding to four levels of irrigation water salinity (0.5 (control), 1.5, 2.5, and 3.5 dS m-¹) and two root management systems (with and without root system division), with five replications. The plants were evaluated for growth, dry mass accumulation, and yield. The irrigation water salinity of 3.5 dS m-1 intensely reduces the plant height, number of fruits, and shoot dry mass of cherry tomato. The shoot fresh mass of cherry tomato was reduced by with root system division. However, this treatment increased the plant height and the number of fruits per plant. Root system division in cherry tomato plants mitigates the deleterious effects of irrigation water salinity up to the electrical conductivity of 1.5 dS m-1, especially on the fruit mass per plant.  

Effect of Irrigation Water Salinity on Soil Characteristics and Microbial Communities in Cotton Fields in Southern Xinjiang, China

Irrigation with saline water is a possible solution to alleviate freshwater shortages. The long-term use of saline water for irrigation requires consideration of the influence of salt on the environmental conditions of the soil. The objective of this field study was to determine the effects of three continuous years of saline water irrigation on physiochemical properties and microbial communities in drip-irrigated cotton fields. The three total dissolved solid (TDS) levels of irrigation water treatments were (i) 1 g L−1 (fresh water, FWI), (ii) 3 g L−1 (brackish water, BWI), and (iii) 7 g L−1 (salt water, SWI). After three years, the electrical conductivity (EC), sodium adsorption ratio (SAR), and contents of K+, Na+, Mg2+, Cl−, and SO42− in the SWI treatment were significantly higher than those in the FWI and BWI treatments, but there were no significant differences in EC and K+ between the FWI and BWI treatments. BWI treatment significantly increased microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), urease, and sucrase contents. The diversity and abundance of bacteria and fungi were not affected by saline water irrigation, but the microbial community structure was altered. Saline water irrigation resulted in an elevation in the bacterial abundance of the phylum Chloroflexi and a decline in Proteobacteria and Actinobacteria. For fungi, the abundance of the phylum Ascomycota in the BWI treatment was greater than that in the FWI and SWI treatments. Linear discriminant analysis effect size (NMDS) results indicated clear variation in the microbiota profiles between the FWI, BWI, and SWI treatments for bacteria. Regarding the fungal microbiota profiles, the BWI and SWI treatments had similar microbiota profiles but were different from the FWI treatment. The number of bacterial biomarkers gradually increased with increasing total dissolved solids of irrigation water, while the number of fungal biomarkers gradually decreased. Additionally, cotton yield was significantly and positively correlated with the observed species of fungi, while it was significantly and negatively correlated with EC. Redundancy analysis (RDA) showed that bacterial community structure was regulated by SAR and fungal community structure was regulated by soil salinity and bulk density (BD). Future research will need to look into how the structure of the microbial community and the associated functional microorganisms are gradually changing with increased irrigation frequency under saline irrigation, as well as explore and screen for advantageous functional microorganisms.

Purslane (Portulaca oleracea L.) salt tolerance assessment

ABSTRACT The present study was aimed to evaluate the effect of irrigation water salinity on some agronomic and physiological attributes of purslane (Portulaca oleracea L.) and its tolerance to salinity stress. The treatments included seven levels of electrical conductivity of irrigation water (0.6 (control), 3, 6, 9, 12, 15, and 18 dSm−1) arranged in the form of a completely randomized design with three replications. The results showed that salinity stress successively decreased agronomic attributes such as root, shoot, and stem dry weight, plant height and leaf area. Physiological attributes such as relative water content as well as ion leakage differently responded to salinity stress. Relative water content response to salinity followed a quadratic regression model with the maximum of 81% at electrical conductivity of 6.87 dSm−1 and the minimum of 65% at highest salinity level of 18 dSm−1. Following an exponential regression model, ion leakage remained relatively the same till irrigation water salinity of 15 dSm−1 and reached to the maximum of 78% at highest irrigation water salinity of 18 dSm−1. In addition, shoot potassium content of purslane under non saline conditions equaled to 11% that was around 10 times more than the typical of potassium sufficient concentration for adequate growth. Moreover, with increasing salinity stress, shoot potassium content decreased to 7% at highest salinity level of 18 dSm−1 of irrigation water. However, with increasing irrigation water salinity, sodium shoot content of purslane was increased from 1.9% at the lowest salinity stress to 6.7% at the highest salinity stress. Based on the linear and nonlinear models, 10% of purslane biomass reduction occurred at soil electrical conductivity of around 10 dSm−1. In addition, 25 and 50% yield reduction observed at 16 and 25 dSm−1 of electrical conductivity of soil saturated paste. Therefore, purslane can be considered as a very salt tolerant plant, halophyte, and can successfully grow in soils with electrical conductivities not suitable for most crops.

Impacts of Saline Water Irrigation on Soil Respiration from Cotton Fields in the North China Plain

Saline water irrigation has been widely used for crop production where agriculture is short of freshwater. However, information about the response of soil respiration to saline water irrigation is limited. To identify the effect of saline water irrigation on soil respiration, the experiment based on long-term saline water irrigation cotton fields (since 2006) was conducted in the Heilonggang area in 2021. Five salinity levels in irrigation water were tested (3.4 [S1], 7.1 [S2], 10.6 [S3], 14.1 [S4], and 17.7 dS m−1 [S5]), and deep ground water (1.3 dS m−1) was used as the control (CK). After 15 years of saline water irrigation, we monitored soil physicochemical properties and soil respiration. In addition, we developed a structural equation model of the relationship between them. The results demonstrated that saline water irrigation significantly reduced soil water-stable aggregate content and porosity by 4.42–45.33% and 6.52–14.10%, respectively, and attenuated soil cellulase, α-glucosidase, and alkaline phosphatase activity. Soil respiration under saline water irrigation was significantly reduced by 5.28–33.08%. Moreover, saline water irrigation with salinity below 10.6 dS m−1 had no significant effect on cotton yield. Moreover, soil salinity (62%), water-stable aggregate content (46%), and soil porosity (25%) had significant effects on soil respiration, and soil porosity had a significant positive effect on soil alkaline phosphatase activity according to the structural equation model. Overall, saline irrigation with salinity below 10.6 dS m−1 can alleviate water shortages and reduce soil carbon emissions without affecting cotton yield in the study area.

Crescimento de porta-enxerto de maracujazeiro silvestre (Passiflora foetida L.) sob salinidades da água de irrigação

ABSTRACT Wild passion fruit species, due to the greater tolerance to environmental stresses, reveal potential as interspecific rootstocks. Passiflora foetida is a wild species potentially tolerant to salinity. Therefore, the objective with the study was to evaluate the effects of irrigation water salinity on the growth of wild passion fruit (P. foetida L.) rootstocks. The experiment was carried out in a protected environment. The treatments consisted of the electrical conductivity of the irrigation water (0.3; 1.0; 2.0; 3.0 and 4.0 dS m-1), distributed in randomized blocks. The assessments were performed at 7, 14, 21, 28 and 35 days after transplanting and consisted of: stem height and diameter, number of leaves, average leaf size, leaf area, and dry matter of shoots, roots and total. In younger rootstocks, the deleterious effects of salinity on height growth and leaf components were observed under lower electrical conductivities, with tolerance increasing with age. However, dry biomass accumulation was more severely restricted by salinity with increasing rootstock age. P. foetida rootstocks are salinity tolerant and can be irrigated with water of up to 4.0 dS m-1.

Effects of saline water irrigation on winter wheat and its safe utilization under a subsurface drainage system in coastal saline-alkali land of Hebei Province, China

Effects of saline water irrigation on winter wheat and its safe utilization under a subsurface drainage system in coastal saline-alkali land of Hebei Province, China

Effect of varieties and nitrogen levels on growth indices of malt barley (Hordeum vulgare) under saline water irrigation

A field experiment was conducted during the winter (rabi)season of 2017–18 and 2018–19 at the Chaudhary Charan Singh Haryana Agricultural University, Hisar, to study the effect of saline water irrigation on growth indices in 4 varieties (‘BH 902’, ‘BH 946’, ‘BH 885’ and ‘DWRB 101’) of barley (Hordeum vulgare L.) at different nitrogen levels (0, 30, 60 and 90 kg/ha). The results showed that, during early growth period both 6-row barley varieties ‘BH 902’ and ‘BH 946’ recorded significantly higher crop-growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), specific leaf weigth (SLW) and leaf-area duration (LAD) than both 2-row barley varieties ‘BH 885’ and ‘DWRB 101’, whereas ‘BH 885’ and ‘DWRB 101’ varieties attained higher values of RGR and NAR after 90 days after sowing (DAS). The CGR and LAD recorded maximum values between 61 and 90 DAS, while RGR and NAR showed the highest values up to 30 DAS irrespective of varieties and nitrogen levels. Application of 90 kg N/ ha significantly enhanced the CGR up to 90 DAS, RGR up to 30 DAS and LAD up to 120 DAS, while NAR values were significantly increased up to 60 DAS with 30 kg N/ha and SLW up to 90 DAS with 60 kg N/ha. The RGR, NAR and SLW were significantly decreased with the application of different nitrogen levels between 91 and 120 DAS as compared to the control. The variety ‘BH 946’ gave the highest grain yield of 5.15 t/ha, being 5.1, 7.3 and 14.7% higher than ‘DWRB 101’, ‘BH 902’ and ‘BH 885’, respectively. Different varieties responded to N application only up to 60 kg/ha. Grain yield of barley was positively correlated with CGR, SLW and LAD but negatively with RGR.

Influence of Salinity on Micronutrient Availability in Soil and Plant in Cowpea-Groundnut Cropping System

An experiment on cowpea-groundnut rotation was conducted to study the effect of saline irrigation water on the availability of micronutrient cations (Fe, Zn, Cu and Mn) in soil and in plants with the effect of a gradual imposition of irrigation salinity (ECiw). Three saline treatments (S1: 2.0 dS m-1, S2: 4.0 dS m-1, S3: 6.0 dS m-1 with a control S0) were maintained in long-term field trials. In summer (cowpea) the soil ECe was raised to 6.01 dS m-1 while in kharif (groundnut) the ECe was 2.21 with S3. A noticeable increase in soil pH (from S0 to S3) was also observed in cowpea (0.48 unit) and groundnut (0.97 unit) seasons. The four available micronutrients in soil did not show any significant trend in both seasons. The concentration of both shoot Fe and Zn increased from control (S0) to highest salinity (S3) to the tune of 19% and 74% respectively in groundnut. The accumulation of root Fe and Zn in groundnut declined to the tune of 53% and 40% respectively with the increasing salinity from S0 to S3. For cowpea, only Zn content showed a decreasing trend among the other micronutrients. Genotypic variation of groundnut did not affect the accumulation of micronutrients as observed by testing eight groundnut genotypes in the present study. A significant drop in yield was noticed for both crops due to saline irrigation, and the groundnut yield varied between 1.6 t ha-1 (in S0) to 0.14 t ha-1 (in S3). This study marks a relevance where very less information is available on micronutrient availability in plant tissues and soil under changing salinity, especially for groundnut, which is considered an important oilseed crop from the national perspective.

Effects of Salinity Stress on Drip-Irrigated Tomatoes Grown under Mediterranean-Type Greenhouse Conditions

Plant tolerance to salinity stress is vital for irrigation scheduling, decision-making, planning and operation, and water resource management. This study is aimed to investigate the effects of irrigation water salinity on water use, growth, physiology, and yield parameters of drip-irrigated tomatoes in two different growing seasons. In addition to control (0.7 dS m−1), three irrigation water salinity levels: 2.5 (low), 5.0 (moderate), and 7.5 (high) dS m−1 were used. In both seasons, autumn 2021 and spring 2022, increased water salinities caused an increase in soil salinity, while a decrease in seasonal crop evapotranspiration. Plant heights did not show significant differences under different salinity levels in autumn 2021, while a meaningful difference among treatments was found in spring 2022. Marketable and total tomato yields, and the leaf area index showed significant decreases under increased salinities in both seasons. Stomatal conductance was not affected by salinity levels. The salt tolerance models for marketable and total fruit yields showed a low threshold and slope value in autumn 2021, contrasting with a high threshold and slope value determined in spring 2022. The results suggest that the salinity slope value should be considered, as well as the salinity threshold value, for decision making in tomato production at different growing seasons.

ANÁLISE MULTIVARIADA DE GRAVIOLEIRA SOB ESTRESSE SALINO E APLICAÇÃO EXÓGENA DE PERÓXIDO DE HIDROGÊNIO

ABSTRACT The objective of this study was to evaluate, through multivariate data analysis, the effect of exogenous application of hydrogen peroxide on the photosynthetic pigments, gas exchange and growth of soursop seedlings under salt stress. The study was conducted in a greenhouse, at Federal University of Campina Grande - Paraíba. The assay was carried out from May to October 2018. The treatments were distributed in a randomized block design, in a 5 × 5 factorial arrangement, corresponding to five levels of irrigation water electrical conductivity - ECw (0.6-control, 1.2, 1.8, 2.4, and 3.0 dS m-1) and five concentrations of hydrogen peroxide - H2O2 (0, 10, 20, 30, and 40 μM), with two plants per plot and four replicates. Irrigation water salinity from 1.2 dS m-1 negatively affected the biosynthesis of photosynthetic pigments, gas exchange and growth of soursop. Application of hydrogen peroxide at the concentration of 20 μM resulted in attenuation of salt stress effects on the biosynthesis of photosynthetic pigments, gas exchange and growth of soursop. Hydrogen peroxide concentrations above 30 μM intensified the deleterious effect of irrigation water salinity on the photosynthetic pigments, gas exchange and growth of soursop.