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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.

Soil acidity is one of the most important soil constraints for wheat growth, and magnesium (Mg) can play a critical role in mitigating the adverse effects of soil acidity on plants. There is, however, limited information available about the influence of Mg nutrition, especially foliar application, on wheat (Triticum aestivum) growth in acidic soil. In a series of glasshouse experiments, Al‐sensitive wheat genotype (ES8) was grown to vegetative stage (Zadoks 23) with or without foliar Mg application at different rates (0, 50, 200 and 1,000 mg Mg/L), and acidic soil was used as the growth medium with or without lime and Mg amendment. The effects of these treatments on plant growth, physiological responses, tissue concentration of Mg, dry biomass accumulation and root length were characterized. Magnesium application to foliage significantly increased (by around 14%) both shoot and root dry biomass compared to the control (0 foliar Mg). No significant variation was observed in response to different Mg salts (sulphate or chloride) applied to either soil or foliage in relation to wheat growth and physiological responses. Other than liming, foliar Mg application (200 mg Mg/L) coupled with Mg application to soil (20 mg/kg soil) provided optimum conditions for wheat growth in an acid soil. Leaf extension rate, chlorophyll content and root length of wheat treated with 200 mg Mg/L foliar application were increased significantly (by 12%, 10% and 23%, respectively) in comparison to plants treated with 0 foliar Mg. Physiological parameters such as net photosynthetic rate, transpiration rate and stomatal conductance were 4‐fold higher in foliar Mg‐treated plants compared with those receiving no foliar Mg. Therefore, applying 200 mg Mg/L to the foliage may assist in minimizing the negative impact of soil acidity on wheat growth.

A pot experiment was conducted to study the growth response of Indian spinach (Basella alba L) to biogas plant residues. There were seven treatments comprising of control, recommended NPK fertilizer and biogas plant residues (BPR) @ 10, 20, 30, 40 and 50 ton ha-1. The treatments were arranged in a randomized complete block design with three replications. Results indicated that number of leaves; plant height and root length and dry weight of shoot and root obtained with recommended NPK fertilizer were statistically similar to those with control treatment except for number of leaves at 60 DAS. Application of biogas plant residues up to 30 ton ha-1 produced similar number of leaves and plant height compared to control and recommended NPK fertilizer at 30 DAS. At 60 DAS, a significantly higher number of leaves and root length was found with above 20 ton ha-1 biogas plant residues and plant height with above 10 ton ha-1 biogas plant residues than control and recommended NPK fertilizer. Fresh weight of shoot and root found with recommended fertilizer dose were significantly higher than that with the control but lower than that with biogas plant residues above 30 ton ha-1 and 10 ton ha-1 , respectively. Biogas plant residues at 30 ton ha-1 and above gave higher shoot and root dry weight than control and recommended NPK fertilizer. However, there were no significant differences between BPR40 and BPR50 for growth parameters of Indian spinach. The study recommends 40 ton ha-1 of biogas plant residues for enhanced growth of Indian spinach.