Effect of salinity stress and surfactant treatment with zinc and boron on morpho-physiological and biochemical indices of fenugreek (Trigonella foenum-graecum).

Micronutrient application has a crucial role in mitigating salinity stress in crop plants. This study was carried out to investigate the effect of zinc (Zn) and boron (B) as foliar applications on fenugreek growth and physiology under salt stress (0 and 120 mM). After 35 days of salt treatments, three levels of zinc (0, 50, and 100 ppm) and two levels of boron (0 and 2 ppm) were applied as a foliar application. Salinity significantly reduced root length (72.7%) and shoot length (33.9%), plant height (36%), leaf area (37%), root fresh weight (48%) and shoot fresh weight (75%), root dry weight (80%) and shoot dry weight (67%), photosynthetic pigments (78%), number of branches (50%), and seeds per pod (56%). Fenugreek's growth and physiology were improved by foliar spray of zinc and boron, which increased the length of the shoot (6%) and root length (2%), fresh root weight (18%), and dry root weight (8%), and chlorophyll a (1%), chlorophyll b (25%), total soluble protein content (3%), shoot calcium (9%) and potassium (5%) contents by significantly decreasing sodium ion (11%) content. Moreover, 100 ppm of Zn and 2 ppm of B enhanced the growth and physiology of fenugreek by reducing the effect of salt stress. Overall, boron and zinc foliar spray is suggested for improvement in fenugreek growth under salinity stress.

Effect of experimental boundary conditions and treatment-time on the electro-desalination of soils.

This study investigates the effect of boundary conditions and treatment-time on the electro-desalination of artificially-contaminated soil. The effect of ion exchange membranes (IEM), calcium chloride (CaCl2), and ethylenediaminetetraacetic acid (EDTA) on the removal of salt (i.e., Na+, Cl-, and Ca2+) and metal (i.e., Co2+ and Fe2+) ions from the soil by electrokinetic (EK) was studied. The outcomes demonstrate that an increase in treatment-time decreases the electroosmosis and ion removal rate, which might be attributed to the formation of acid-base fronts in soil, except in the IEM case. Because a high pH jump and electroosmotic flow (EOF) of water were not observed within the soil specimen due to the IEM, the removal of ions was only by diffusion and electromigration. The collision of acid-base fronts produced a large voltage gradient in a narrow soil region with a reduced electric field (EF) in its remaining parts, causing a decrease in EOF and ion transport by electromigration. The results showed that higher electroosmosis was observed by using CaCl2 and EDTA; thus, the removal rate of Co2+, Na+, and Ca2+ was greater than Cl- due to higher EOF. However, for relatively low EOF, the removal of Cl- exceeded that of Co2+, Na+, and Ca2+, possibly due to a lack of EOF. In addition, the adsorption of Fe2+ in soil increased with treatment-time due to the corrosion of the anode during all EK experiments except in the case of IEM, where an anion exchange membrane (AEM) was introduced at the anode-soil interface.

Bio-diesel production of sunflower through sulphur management in a semi-arid subtropical environment.

Energy security is a prime focus of policy makers to support agriculture, industrialisation, and transportation. Due to limited conventional energy sources, there is a need to harness non-conventional energy sources. In this regard, one of the proposed approaches is using biomass (e.g. energy crops) to produce biofuel-a renewable source of energy. Sunflower has several agronomic features to be exploited for a renewable, non-conventional, and environment-friendly source of bioenergy. Sulphur (S) fertilisation holds key for realising sunflower potential for seed and oil yield. In response to variable S supply rates, here we compared and quantified sunflower yield (seed, oil, and biodiesel) and biodiesel quality according to the ASTM international standards. We used a combined approach of field experimentation and rigorous lab analysis. Firstly, in a field experiment laid out in randomised complete block design with split-plot arrangement, response of two local sunflower hybrids (FH-331 and FH-689) to four S supply rates (0, 25, 50, 75 kg S ha-1) was evaluated in terms of agronomic traits. Experimental data showed that fertilisation of S significantly influenced growth and yield (seed, oil) traits; the response was different between two hybrids which also interacted with S supply rate. FH-331 recorded the highest achene yield at S fertilisation of 75 kg S ha-1, whereas FH-689 recorded the highest achene yield at 50 kg ha-1; achene yield of FH-331 was 13.6% higher than FH-689. Compared to control, S at 75 kg S ha-1 increased oil yield of FH-331 by 22% whereas S at 50 kg ha-1 increased oil yield by 23% of FH-689. Seed samples were analysed for different biodiesel quality parameters. The ranges of all quality parameters of sunflower biodiesel such as viscosity, calorific values, acid value, iodine value, saponification value, cetane number, and pour point were in ASTM standard range. We conclude that sunflower is a promising and sustainable option for producing biodiesel, the potential of which can be increased by optimal S management under field conditions.