Salinity Management Research Articles

Use of HYDRUS-1D–GIS tool for evaluating effects of climate changes on soil salinization and irrigation management

ABSTRACTIn this study, HYDRUS-1D model was coupled with geographic information system (GIS) for evaluating the effects of climate changes on soil salinization. The coupled HYDRUS-1D–GIS system was applied in a coastal region (Gabes Oasis) for evaluating the effects of various climate change scenarios on temporal change in soil electrical conductivity (EC) and for developing irrigation practice that desalinates soils. The climate change scenarios were selected based on the climate change projections by 2050 and increased irrigation water allocations. There were three main findings. First, HYDRUS-1D and GIS were successfully coupled and used to perform simulation with consideration of the large differences in soil texture in the studied oasis. Second, for all climate change scenarios, spatial extent of EC for 2050 is projected to reach levels (> 4 dS m−1) corresponding with being classified as saline soils. Third, with climate changing as simulated, it is recommended to increase irrigation water application with 20% or more than today to avoid further increases in soil EC. Overall, this study can be used as a guide to implement the most appropriate strategy of soil and water management.

Rootzone salinity monitoring and management in Acacia ampliceps irrigated with three water salinity levels in Entisols of United Arab Emirates

Rootzone salinity monitoring and management in Acacia ampliceps irrigated with three water salinity levels in Entisols of United Arab Emirates

Environmental and economic impacts and trade-offs from simultaneous management of soil constraints, nitrogen and water

Nitrogen loss and soil salinity are two key global issues for sustainable farming systems. Simultaneous mitigation of these issues requires contrasting nitrogen and water management practices, warranting a holistic understanding of the resulting nitrogen losses. This research aims to understand the i) interactive effects of salinity management, soil conditions and rainfall variability on nitrogen leaching, and ii) general trends in economic and environmental trade-off from reduced leaching fraction and nitrogen applications to minimise nitrogen loss. Simulations were run for 116 years (1900–2015) taking irrigated Australian cotton as a reference. Results showed that nitrogen leaching increased with leaching fraction, from 1 to 4 kg ha−1 for a soil comprising of high plant available water capacity + low initial soil nitrogen to as high as 46 kg ha−1 for its counterpart condition. Leaching increased with in-crop rainfall, the wettest conditions (679 mm) contributing for, up to 75% additional leaching. Depending on soil salinity, trade-off involving leaching fraction reduction by 0.05 units (from typical 0.20) resulted in lower drainage (up to 6%) and lower leaching (up to 5%) but also reduced the net returns (up to 50%). In contrast, nitrogen fertiliser reduction by 25 kg ha−1 (from typical 250 kg ha−1) showed little benefit to leaching reduction, but led to lower economic losses, higher nitrogen use efficiency and lower nitrous oxide emission. The study suggests that nitrogen losses under salinity can be alleviated through avoiding over-irrigation but without compromising the critical leaching requirements, applying fertiliser according to the soil spatial variability, and maximising rainwater use to meet leaching needs.

Assessment of groundwater quality for the suitability of irrigation and its impacts on crop yields in the Guna district, India

This study was performed to understand the impact of groundwater quality on the crop yields and its suitability for the irrigation. The hydrogeochemical assessment indicates chemical weathering is prevalent in the aquifer system. Low sodium-hazard observed in almost all samples. High salinity-hazard observed in the shallow aquifer indicates leaching of contaminants from the surface. Salinity-hazard statistics indicates ∼27.60% groundwater suitable for irrigation, ∼47.65% groundwater considerable for irrigation of selected crops whose salinity tolerance limit is high, ∼13.44% groundwater (fresh-brackish) cause problem in the soil and ∼11.31% groundwater unsuitable for the irrigation.Salinity tolerance limit indicates yield (%) of the few crops remain unaffected. These crops are Hordeum vulgare (Barley), Gossy pium (Cotton), Beta vulgaris (Sugar-beet), Cynodon dactylon (Bermuda-grass), Thinopyrum ponticum (tall Wheat-grass), Thinopyrum intermedium (Wheat-grass) etc. The yield potential (%) partially affected in the few crops like Arachis hypogaea (Groundnut) (∼95.30%), Oryza sativa (Rice) (∼93.29%), Carthamus tintorius (Safflower) (∼97.32%), Sorghum bicolor (Sorghum) (∼95.97%), Glycine max (Soybean) (∼97.32%), Triticum aestivum (Wheat) (∼99.33%), Brassica oleracea var. italica (Broccoli) (∼92.62%), Cucumis sativus (Cucumber) (∼90.60%), Solanum lycopersicum (Tomato) (∼90.60%), Phalaris aquatic (Harding-grass) (∼97.96%), Lolium perenne (Perennial ray-grass) (∼97.99%), Sorghum drummondii (Sudan-grass) (∼92.62%), Festuca arundinacea (tall-Fescue) (∼95.30%), Lotus corniculatus (Trefoil-small) (∼97.32%), Phoenix dactylifera (Date-palm) (∼95.97%), Ficus carica (Fig) (∼95.97%), Olea europaea (Olive) (∼95.97%), Punica granatum (Pomegranate) (∼91.28%) etc. Few crops sensitive to salinity-hazard indicate low-yield potential listed as Phaseolus vulgaris (Bean) (∼36.91%), Daucus carota (Carrot) (∼36.91%), Fragaria ananassa (Strawberry) (∼36.91%). This groundwater is suitable for the irrigation of crops like Barley, Cotton, Sugar-beet, Wheat, Wheat-grass, Bermuda-grass, etc. But this groundwater can be used for irrigation after salinity management for the crops like Groundnut, Rice, Soybean, Broccoli, Cucumber, Tomato, Harding-grass, tall Fescue, Trefoil-small, Date-palm, Fig, Olive, and Pomegranate. The similar range of the crop yields observed in both Soil Water Salinity (SWS) Model and Ayers and Westcot Model, if the salinity of the irrigation water is low (≤1.5 mS/cm). While low reduction in crop yields observed according to SWS Model in comparisons to Ayers and Westcot Model if the salinity of the irrigation water is high (>1.5 mS/cm). The major reduction in crop yields observed in Ayers and Westcot Model, while the moderate decline in crop yields observed in SWS Model at higher salinity. Crop yield in the study area can be improved by implementing proper irrigation water management.

Using proximal sensor data for soil salinity management and mapping

Over the past five decades, increased pressure caused by the rapidly growing population has resulted in a reclamation of agricultural and urban buffer zones along China's coastline. However, information about the spatio–temporal variation of soil salinity in these reclaimed regions is limited. As such, obtaining this information is crucial for mapping the variation in saline areas and to identify suitable salinity management strategies. In this study, we employed EM38 data to conduct digital soil mapping of spatio–temporal variation and map these variations of different site-specific zones. The results indicated that the distribution of soil salinity was heterogeneous in the middle of, and that the leaching of salts was significant at the edges of, the study field. Afterwards, fuzzy-k means algorithm was used to divide the site-specific management zones within the time series apparent soil electrical conductivity (ECa) data and the spatial correlations of variation. We concluded that two management zones are optimal to guide precision management. Zone A had an average salinity level of about 165 mS m−1, in which salt-tolerant crops, such as cotton and barley can grow normally, while crops such as soybean and cowpeas may be planted using leaching and increasing the mulching film methods to reduce the accumulation of salt in surface soil. In Zone B, there was a low salinity level with a mean of 89 mS m−1 for ECa, which allows for rice, wheat, and a wide range of vegetables to be grown normally. In such situations, measures such as an optimized combination of irrigation and drainage, as well as soil amendment can be taken to adjust and control the salt content. Particularly, flattening the land with a large-scale machine was used to improve the ability of micro-topography to influence salt migration; rice and other dry, land crops were planted in rotation in combination with utilizing salt-leaching multiple times to speed up desalinization.

Waterlogging and coastal salinity management through land shaping and cropping intensification in climatically vulnerable Indian Sundarbans

Sundarbans in West Bengal, India located in the eastern coast of the Bay of Bengal is one of the vulnerable zones subjected to abrupt climate change. The region receives 2.7 times surplus rainfall as compared to crop evapotranspiration during monsoon months causing widespread waterlogging of the low lying agricultural fields and impedes the productivity. The present study assessed the effects of different land shaping models namely, farm pond (FP), deep furrow and high ridge (RF) and paddy cum fish (PCF) systems for rainwater harvesting in restoring the productivity of degraded coastal soils in Sundarbans. A water balance was run to estimate the soil moisture, crop evapotranspiration, runoff and water depth in the reservoir during normal, excess and deficit rainfall years. The average annual harvested runoff was 2709, 1650 and 1169 m3 per hectare in FP, RF and PCF systems, respectively. The runoff going out of the system was 19.5, 29.1 and 27.75% of the annual rainfall in FP, RF and PCF systems, respectively, whereas in monocrop rice-fallow system it was 34.6% of the annual rainfall. We estimated all the three components of water footprints (WF) i.e., blue WF (WFblue), green WF (WFgreen) and gray WF (WFgray) as an aggregative indicator to evaluate environmental impact. The results indicated that total as well as the components of WF was higher in rice-fallow and rice-rice systems than in each of the land shaping system. Large scale adoption of different land shaping systems increased the cropping intensity and net farm income and there was reduction in salinity during summer and waterlogging during rainy season and overall improvement in soil quality. The dominant soluble salts identified in the study region were NaCl and MgSO4.

Extracts from Yeast and Carrot Roots Enhance Maize Performance under Seawater-Induced Salt Stress by Altering Physio-Biochemical Characteristics of Stressed Plants

Damage to plant productivity due to soil salinity is a major agricultural problem, necessitating the development of effective salinity management measures. Here, we sought the potential effects of yeast and carrot extracts, and their associated mechanisms in the alleviation of seawater-induced salt stress in maize. Pretreatment of maize seeds with yeast or carrot extract provided maize plants with enormous abilities in reducing growth inhibition and biomass loss when exposed to seawater. The better growth performance of yeast extract- and carrot extract-primed plants under saline conditions coincided with improved protection of the photosynthetic pigments, chlorophylls and carotenoids. The primed plants also restricted Na+ accumulation in both roots and shoots while maintaining a higher K+ content and lower Na+/K+ ratio when compared with that of non-primed plants. Yeast extract and carrot extract also potentiated salt tolerance mechanisms by accelerating the production of osmolytes, as evidenced by accumulating levels of total free amino acids and soluble sugars, especially in the roots of primed plants during salinity. The enhanced levels of ascorbic acid and phenolic compounds, and the heightened activities of reactive oxygen species-detoxifying enzymes superoxide dismutase, catalase, and ascorbate peroxidase with concurrent reduction of lipid peroxidation in the leaves of primed plants clearly indicated a positive impact of yeast extract- and carrot extract-priming on the antioxidant system of maize under salt stress. Our results together suggest decisive roles of yeast extract and carrot extract in the management of salt-induced adverse effects in economically important maize, and perhaps other crops.

Gas exchanges and production of watermelon plant under salinity management and nitrogen fertilization

ABSTRACT In the Brazilian semi-arid region, the occurrence of water with high salt concentrations is common, making it a limiting factor for the agricultural production. The water-use salinity management strategies are an alternative capable of minimizing the deleterious effects of the stress on plants. This study aimed to evaluate the gas exchanges and production of ‘Sugar Baby’ watermelon plants under strategies of irrigation with saline water and nitrogen fertilization. The experiment was conducted in a randomized block design, arranged in a 6 x 2 factorial scheme, with five replicates, corresponding to six irrigation strategies with saline water applied at different phenological stages of the crop (control - irrigation with low-salinity water throughout the entire crop cycle, and salt stress at the vegetative stage, vegetative/flowering stage, flowering, fruiting and fruit maturation) and two nitrogen rates (50 % and 100 %, equivalent to 50 mg and 100 mg of N kg-1 of soil). Two levels of water salinity were studied: one with a low and the other with a high level of electrical conductivity (0.8 dS m-1 and 3.2 dS m-1, respectively). The salinity of 3.2 dS m-1 in the vegetative/flowering and fruit maturation phases decreases the stomatal opening, transpiration and CO2 assimilation rate. The level with 50 % of N provides a higher assimilation rate of CO2 and fresh fruit mass. The watermelon plant expresses a greater sensitivity to saline stress in the vegetative and flowering phases, a situation that results in a decreased fruit size.

A Review on Plant Responses to Soil Salinity and Amelioration Strategies

Soil salinity is a major abiotic stress, limiting plant growth and development worldwide. Plants grown under saline soil condition experiences a significant amount of high osmotic stress, ion toxicities and nutritional disorder, and these are responsible for poor soil physical condition as well as lead to reduced plant productivity. Plants exhibit a number of responses under salt stress by affecting morphological, physiological and biochemical process. A complete understanding of how plants respond to soil salinity and comprehensive management approaches of combining physiological and biochemical attributes with molecular tools are essential for mitigating the adverse effects of salinity on plant growth and productivity. Recent reports on the plant responses due to soil salinity highlighted the importance of integration of different advanced strategies to address the problem of soil salinity. This review will focus on morphological and physiological changes of plants under saline soil and an overview of suitable strategies to regulate plant adaptation and tolerance to salinity stress.

Kentucky Bluegrass Growth and Quality as Affected by Salt Type and Concentration

Core Ideas Salinity adversely affected Kentucky bluegrass growth and performance. Chloride salts were more detrimental to Kentucky bluegrass than sulfate salts when applied at the same electrical conductivity. Kenblue had a higher growth rate than Moonlight’under the saline condition at the seedling stage; however, Moonlight outperformed Kenblue at the vegetative growth stage. The growth and functionality of turfgrasses are often challenged by high soil salinity. Previous research mainly focused on plant responses to Cl− salt–induced saline conditions (e.g., NaCl). However, in some regions, including California and North Dakota, in salt‐affected soils the predominant cation is Mg2+ and the predominant anion is SO42−. The responses of turfgrass species to such salinity conditions have not been well documented. In this research, the responses of Kentucky bluegrass (Poa pratensis L.) cultivars Kenblue and Moonlight at the seedling growth and the vegetative growth stages to different salt type (NaCl, Na2SO4, MgCl2, and MgSO4) and concentration (5–20 dS m−1) were investigated. Results showed that shoot dry weight (SDW), root dry weight (RDW), root length (RL), and visual quality of the two turf cultivars decreased with increasing salt concentration at both growth stages. Specific root length increased to 235.7% of the control at the seedling growth stage but decreased to 71.6% of the control at the same salt concentration at the vegetative growth stage. Under the saline condition, Kenblue showed higher SDW (52.1%), RDW (74.4%), and RL (20.6%) than Moonlight at the seedling growth stage; however, Moonlight performed better than Kenblue at the vegetative growth stage. The two turf cultivars were more tolerant to Na2SO4 and MgSO4 stress than to NaCl and MgCl2 stress. Our research indicates that turfgrass managers need to consider plant material (cultivar and growth stage), salt type, and salt concentration to develop a successful salinity management plan.

Prediction of salt balances in irrigated soils along the lower Vaal River, South Africa

In arid and semi-arid regions irrigation tends to degrade soil and water quality through salt accumulation with devastating effects on some crops. This is, according to irrigators, also the case along the lower Vaal River in South Africa. Properly calibrated and tested salinity models could assist the agricultural community in improving salinity management under irrigation.This paper reports on, firstly, salt balances of soils in this region being irrigated for different time periods, and secondly, salt content changes that can be expected as a consequence of future irrigation. Two empirical models, viz. a general and specific salt-balance model were used together with existing water- and soil-quality data to generate such information. The soils selected for this study had been irrigated for periods of between 17 to 53 years. Over these periods addition of salts as a result of farming practices varied between 79 and 280 t·ha-1, with irrigation water being the major contributor. Between 78% to 87% of the salts added to the soils had been leached from the root zone Despite these large amounts of salts that have been removed, certain irrigation practices have promoted the build-up of salts in some of the soils. The freely drained sandy soils irrigated by centre pivot are of particular interest. Poor management of this system can reduce crop yields. On account of inadequate leaching salts are building up to levels that impair the potential evapotranspiration level of maize. Predictions also show that irrigation should rather be withdrawn from soils with poor internal drainage properties, such as the Arcadia soil at Spitskop. In contrast, flood irrigation on certain duplex soils, such as the Valsrivier at Vaalharts, with relatively good internal drainage properties, can improve their quality.Keywords: drained soils, root zone, soil quality, undrained soils, water quality

Mapping soil salinity in the East Nile Delta using several methodological approaches of salinity assessment

Soil salinization is one of the most serious problems facing soil fertility, crop productivity and sustainable agricultural development in Egypt. The risk of salinization is present, when it leads to toxicity. This study focuses on evaluation of soil salinization at East of Nile Delta to enhance management strategy program using geographical information system (GIS). Two different classifications of salt-affected soils, agronomic classification and Russian classification, were used. Ninety-two surface soil samples were collected at depth 0–30 cm. Inverse distance weighting (IDW) was used for spatial distribution mapping of soil salinity and salinization degree. Normalized Difference Vegetation Index (NDVI) was used to identify the correlation between vegetation density cover and soil salinity levels. The obtained data and salinity maps of the studied area presented that salinity levels according to agronomic classification occupied areas of 60% – non-saline, 15% slightly saline, 13% moderately saline, 2% strongly saline and 10% for extremely saline level. Nevertheless, soil salinization degrees according to Russian classification located 71% – non-saline, 10.5% – slight saline, 9% – moderate saline, 3.8% strongly saline and 5.7% for very strongly saline of the investigated area. On the other hand, the results showed reasonable correlation between NDVI, salinity (EC) and total toxic salts (%) (R2 = 0.58 with salinity and 0.65 with toxic salts). Finally, precise soil salinity management should consider the concentration of total toxic salts and chemical composition of salts.

Soil salinity management for increasing potato yield in the coastal area of southern Bangladesh

The study was conducted at farmers’ field of Charfashion upazila in Bhola district under AEZ-18 during the Rabi season of 2015-2016 and 2016-2017 to find out suitable soil salinity management practice(s) for maximizing potato yield as well as farmers’ income. Two planting systems viz. raised bed and flat land, and four management systems with fertilizers and mulching were considered in a factorial experiment. The rate of increase in soil salinity in raised beds was significantly lower than that of flat land. On an average, raised bed planting produced 13.04% higher tuber yield than flat land planting. The combination of raised bed + recommended fertilizer (RF) with cowdung @ 5 t ha-1 as IPNS+ straw mulch (@ 3.5 t ha-1) produced the highest tuber yield in both the years (average 21.66 t ha-1) and it was 75.10% higher than flat planting system with no mulch. This treatment combination also provided the highest average gross margin (Tk. 115945 ha-1) and BCR (2.26). Besides, combination of raised bed + RF+25% K+ straw mulch provided average tuber yield (20.91 t ha-1), gross margin (Tk. 110969 ha-1) and BCR (2.25), which were very close to above treatment combination. The lowest average potato yield (12.51 t ha-1), gross margin (Tk. 39835 ha-1) and BCR (1.50) were obtained from combination of flat land planting + RF +no mulching. So, combination of raised bed + mulching+ RF along with IPNS basis cowdung @ 5 tha-1 or 25% extra K can help minimize soil salinity and produce significantly higher potato yield in the coastal areas.Bangladesh J. Agril. Res. 43(4): 655-668, December 2018

Salinity Management in the Shatt Al-Arab River

Shatt al-Arab River is originated at the confluence of Tigris and Euphrates in al-Qurna town in southern Iraq. Two other tributaries; the Karun and the Karkheh rivers; join the river downstream from the eastern bank. The length of Shatt al-Arab is about 192 km from its origin to its mouth in the Gulf. The width of the Shatt varies between 250 m at Qurna and 750 m at its mouth at Rass al-Bisha. The salinity of Shat al-Arab has increased steadily for the last four decades. High salinity of the shatt waters hindered their use and made them unfit for most domestic, agricultural and industrial uses. Salinity as high as 18500 ppm was recorded in the City of Basra on the year 2009. The prime cause of the salinity problem is the reduction of fresh water inflow from all the contributing rivers; the high salinity of the inflow from the Euphrates; the marshes; and Garmat Ali River. The research paper recommends an environmental (a minimum instream) flow of 145 cms and several engineering works on the lower parts of the Euphrates and the Tigris rivers to assure the delivery of the proposed flow.

Defensive Investment in Municipal Water Hardness Reduction

We produce estimates of household's willingness to pay (WTP) for reduction in water hardness using a defensive investment framework. Using total dissolved solids (TDS) data observed in municipal water supplies in combination with product-by-store level point-of-sale scanner data on consumable water softening product sales, we provide among the first revealed preference estimates of WTP for water hardness reduction and quality control. Using instrumental variable regressions, we find that household's marginal WTP increases as the observed TDS in municipal water increases. Aggregating these estimated WTP at county level, we show how total WTP varies geographically, after controlling for income and fixed effects. Our estimations provide evidence that households have a non-negligible WTP for water hardness reduction, which has important policy implications for optimal water hardness management by municipal water authorities, and those policies aimed to target salinity management within surface and subsurface water supplies.

Salinity Management in the Murray‐Darling Basin: A Transaction Cost Study

AbstractTransaction costs are fundamental to implementing, evaluating, and monitoring public policy/programs for social, economic, and/or environmental welfare. Empirical accounting for transaction costs helps identify and evaluate adaptive public policy or program arrangements that improve future institutional choices under uncertainty. However, examples of empirical transaction cost studies are few, due largely to persistent measurement challenges and limits to transaction cost comprehension. A lack of studies limits both insights into the importance of transaction costs in institutional design and validation of theories surrounding cost trajectories over time under different institutional arrangements. In this paper we apply time series analysis to a unique database of public salinity management program transaction costs in Australia's Murray‐Darling Basin. Our study provides insights into the role of transaction costs in institutional efficiency and on empirical approaches to considering relationships between observed transaction cost trajectories and the efficiency of associated institutions. Our results indicate that the Murray‐Darling Basin salinity management program succeeded in generating persistent declines in transaction costs and river salinity levels over time. We suggest some possible reasons for this that are associated with institutional design and reflect on what these findings may mean for other jurisdictions.

Soil Salinity Mapping of Urban Greenery Using Remote Sensing and Proximal Sensing Techniques; The Case of Veale Gardens within the Adelaide Parklands

More well-maintained green spaces leading toward sustainable, smart green cities mean that alternative water resources (e.g., wastewater) are needed to fulfill the water demand of urban greenery. These alternative resources may introduce some environmental hazards, such as salt leaching through wastewater irrigation. Despite the necessity of salinity monitoring and management in urban green spaces, most attention has been on agricultural fields. This study was defined to investigate the capability and feasibility of monitoring and predicting soil salinity using proximal sensing and remote sensing approaches. The innovation of the study lies in the fact that it is one of the first research studies to investigate soil salinity in heterogeneous urban vegetation with two approaches: proximal sensing salinity mapping using Electromagnetic-induction Meter (EM38) surveys and remote sensing using the high-resolution multispectral image of WorldView3. The possible spectral band combinations that form spectral indices were calculated using remote sensing techniques. The results from the EM38 survey were validated by testing soil samples in the laboratory. These findings were compared to remote sensing-based soil salinity indicators to examine their competence on mapping and predicting spatial variation of soil salinity in urban greenery. Several regression models were fitted; the mixed effect modeling was selected as the most appropriate to analyze data, as it takes into account the systematic observation-specific unobserved heterogeneity. Our results showed that Soil Adjusted Vegetation Index (SAVI) was the only salinity index that could be considered for predicting soil salinity in urban greenery using high-resolution images, yet further investigation is recommended.

Climate Change and Sustainable Management of Salinity in Agriculture

Climate Change and Sustainable Management of Salinity in Agriculture

Salinity Management in Pima Cotton Fields Using Sulfur Burner

Core Ideas Salinity and sodicity in irrigated cotton fields are reducing soil productivity, lint yield, and fiber quality in arid and semiarid regions of the world. Sulfur burner treatment of irrigation water can be used to tap native CaCO3 to produce CaSO4 in a safe manner. Calcium sulfate increases Ca availability in the root zone to counter Na, improve soil permeability, and leach salts to deeper depths. Salinity and sodicity are the dual problems affecting soil productivity, lint yield, and fiber quality in the irrigated pima cotton (Gossypium hirsutum L.) fields in far west Texas. This field study evaluated the effects of S burner‐treated blended irrigation water on sodicity and salinity of the root zone, cotton lint yield, and fiber quality. Results indicated that pre‐study soil salinity and sodicity exceeded the threshold levels in many areas within the 9.2‐ha study site. One year of irrigation with S burner‐treated water resulted in 19% reduction in salinity of the upper 0‐ to 30‐cm depth and redistribution of salts at deeper depths. Average sodium adsorption ratio (SAR) of study site soils decreased by 3 to 5% at 0‐ to 15‐, 30‐ to 45‐, and 45‐ to 60‐cm depths and reduction in the SAR range for 15‐ to 30‐ and 60‐ to 75‐cm depths indicated redistribution of Na. Irrigation with S burner‐treated blended water increased annual cotton lint yield by 20% compared with long‐term average and improved fiber quality. However, 1 yr of irrigation with S burner‐treated water did not reduce the maximum soil ECe and SAR values below the threshold levels at different depths. Multi‐year studies are needed to confirm our results and quantify the duration required to restore soil quality, cotton yield, and fiber quality.

Implications of physiological integration of stolon interconnected plants for salinity management in soilless strawberry production

Abstract Salinity can be a greater problem in shallow soilless media than in field soils because of the small root zone volume that commonly occurs in such systems. Clonal integration (the capability of reciprocal resource translocation among interconnected plantlets through their shared stolon) can alleviate salinity injury in strawberry (Fragaria x ananassa ‘Albion’). Here we report the effect of clonal integration on leaf area, shoot and root dry biomass, net CO2 assimilation rate (AN), stomatal conductance (gs), intercellular CO2 (ci), transpiration (E), and instantaneous water use efficiency (WUE). Interconnected mother-daughter pairs of strawberry plants were grown in stirred solution culture under greenhouse conditions. Combinations with independent salinity levels on the mother and daughter side were imposed in a 4 × 3 complete randomized factorial design. Salinity levels of 1, 3, 6 and 9 dS m−1 were established by adding calcium chloride (CaCl2) and sodium chloride (NaCl) as needed to a 1 dS/m nutrient solution. Interconnected daughter plants grew in 0.2 CaSO4, or the 1 dS m−1 nutrient solution, or the same solution supplied to the mother plant. Values of all measured attributes decreased with salinity, with the exception of Ci, which increased at the highest salinity combination of mother and daughter plants. In contrasting salinity conditions, clonal integration ameliorated salt stress in mother plants through water transfer from daughter to mother plants. Interclonal resource translocation was mainly driven by the contrast in stress intensity between mother and daughter plants.