The salinization of soil is responsible for the reduction in the growth and development of plants. As the global population increases day by day, there is a decrease in the cultivation of farmland due to the salinization of soil, which threatens food security. Salt-affected soils occur all over the world, especially in arid and semi-arid regions. The total area of global salt-affected soil is 1 billion ha, and in India, an area of nearly 6.74 million ha−1 is salt-stressed, out of which 2.95 million ha−1 are saline soil (including coastal) and 3.78 million ha−1 are alkali soil. The rectification and management of salt-stressed soils require specific approaches for sustainable crop production. Remediating salt-affected soil by chemical, physical and biological methods with available resources is recommended for agricultural purposes. Bioremediation is an eco-friendly approach compared to chemical and physical methods. The role of microorganisms has been documented by many workers for the bioremediation of such problematic soils. Halophilic Bacteria, Arbuscular mycorrhizal fungi, Cyanobacteria, plant growth-promoting rhizobacteria and microbial inoculation have been found to be effective for plant growth promotion under salt-stress conditions. The microbial mediated approaches can be adopted for the mitigation of salt-affected soil and help increase crop productivity. A microbial product consisting of beneficial halophiles maintains and enhances the soil health and the yield of the crop in salt-affected soil. This review will focus on the remediation of salt-affected soil by using microorganisms and their mechanisms in the soil and interaction with the plants.

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Over the past decade, scientific studies have increasingly concentrated on the effects of global phosphorus (P) scarcity on food security. A comprehensive strategy that considers demand reduction and recycling possibilities is needed to address the global P scarcity. Reduced tillage along with crop residue retention could decrease fixation of P in soil, improve labile P content and enhance organic-P (Po) buildup and its mineralization by phosphatases; this could be an extra benefit of conservation agriculture (CA) in soils. To study the impact of long-term CA on soil organic and inorganic P fractions and their distribution, a long-term field trial was conducted under a maize-based cropping system with different tillage (zero tillage (ZT), permanent bed (PB) and conventional till (CT) and cropping system (maize–wheat–mungbean (MWMb), maize–chickpea–sesbania (MCS), maize–mustard–mungbean (MMuMb) and maize–maize–sesbania (MMS)). Phosphorus dynamics were studied through sequential fractionation (organic and inorganic P) at 0–5 and 5–15 cm soil depth. The findings showed that a higher amount of soluble and loosely bound P (SL-P) was detected in ZT among the inorganic P fractions, whereas iron-bound P (Fe-P), aluminum-bound P (Al-P), reductant soluble P (RES-P) and calcium-bound P (Ca-P) were found higher in CT in both soil depths. Among Organic-P fractions, moderately labile and non-labile Po was found higher in PB and ZT but, in the case of labile Po, it was found insignificant with respect to tillage operations. Significant synergistic effects of winter legume (chickpea) with summer legumes (sesbania and mungbean) in crop rotation were observed on SL-P, Labile Po, Humic acid-Po, Alkaline phosphatase and MBP at 0–5 and 5–15 cm soil depths. Given the potential relevance of understanding P dynamics for efficient P management in long-term conservation agriculture practices, our findings offers critical new insight for the P management for sustainable development.

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A field experiment was initiated in the year 2013 while current study was undertaken after two years of experimentation, i.e. in the year 2015-16 to study the effect of crop residue retention (CCR) and phosphorus fertilization in maize (Zea mays L.)-wheat (Triticum aestivum L.) cropping system on yield and P use efficiency of maize at IARI Research Farm, New Delhi. Results indicated that crop residue retention significantly enhanced grain and straw yield of maize from 5.44 and 8.01 t/ha (No-CR) to 5.88 and 8.40 t/ha in 75% CR, respectively. Whereas, the treatment 50% RDP + PSB and AM significantly enhanced grain (6.22 t/ha), straw (9.07 t/ha) and biological (15.2 t/ha) yield of maize over 100% RDP, except grain yield. The combined use of 50% RDP + PSB and AM increased the grain yield by 1.46% over 100% RDP. The enhancement in total P uptake was 69% and 14% due to application of 50%RDP + PSB and AM and 75% CRR, respectively over control. The higher apparent recovery (ARP) of P, 18.1% and 28.2% were recorded under 75% CR and 50% RDP + PSB and AM treatment, respectively, whereas highest agronomic efficiency (AE) of P (34.7and 51.2 kg grain/kg P) were found under 25% CRR and 50% RDP + PSB and AM treatment, respectively. Soil biological properties, viz. DHA, MBC and MBP also significantly enhanced under 75% CRR and 50% RDP + PSB and AM treatments.