Endophytic bacteria (EB) are both a novel source of bioactive compounds that confer phytopathogen resistance and inducers of secondary metabolites in host plants. Twenty-seven EB isolated from various parts of Metasequoia glyptostroboides, Ginkgo biloba, Taxus brevifolia, Pinus densiflora, Salix babylonica, and S. chaenomeloides could produce salicylic acid (SA). The highest producers were isolates EB-44 and EB-47, identified as Pseudomonas tremae and Curtobacterium herbarum, respectively. Nicotiana benthamiana grown from EB-44-soaked seeds exhibited a 2.3-fold higher endogenous SA concentration and increased resistance against P. syringae pv. tabaci, the causative agent of tobacco wildfire disease, than plants grown from water-soaked seeds. N benthamiana and N. tabacum grown from EB-44-treated seeds developed 33% and 54% disease lesions, respectively, when infected with P. syringae pv. tabaci, and showed increased height and weight, in addition to 4.6 and 1.4-fold increases in nicotine accumulation, respectively. The results suggest that SA-producing EB-44 can successfully colonize Nicotiana spp., leading to increased endogenous SA production and resistance to tobacco wildfire disease. The newly isolated EB can offer an efficient and eco-friendly solution for controlling wildfire disease and nicotine accumulation in Nicotiana, with additional application for other important crops to increase both productivity and the generation of bioactive compounds.

Organic matter plays an important role in the health and productivity of soils, but its depletion is a common problem in households in low-income countries. This is due to lack of and competing uses for organic resources, and limited information on recycling methods. Therefore, here we review low-cost and labour-efficient innovations to improve recycling of organic wastes, stabilising residues so that soil organic matter can be increased with less inputs and enhancing nutrient content to produce a more effective organic fertiliser. Composting, anaerobic digestion and pyrolysis are all processes that stabilise organic matter. Innovations in treatments are needed to improve stabilization and control the release of nutrients so that they are available to crops in the right amounts and at the right time. This can be achieved by maintaining appropriate treatment conditions: for composting, carbon to nitrogen ratio 25–35, carbon to phosphorus ratio ∼50, pH 5.5–8.5 and 50%–60% moisture content; for anaerobic digestion, carbon to nitrogen ratio 20–35, bulk density 0.6–0.8 g cm ⁻³ , lignin content < 7.5%, pH 6.8–7.4 and moisture content 85%–95%; and for pyrolysis, carbon to nitrogen > 40 and moisture content < 20%. Different methods to achieve these ideal conditions are discussed, including appropriate choice of treatment method, co-composting/co-digestion for ideal nutrient content, enhancing nutrients using collected urine, nitrogen-fixing plants, bioslurry or by inoculating with bacterial communities, absorbing excess nutrients on biochar, adjusting pH using wood ash or biochar, pre-treatment to break down lignin and cellulose, and designs to achieve ideal moisture and temperature. Innovations should also ensure that treatment processes do not overuse or compete with other important household resources, such as finances, water or labour. We draw together findings to identify methods with most potential to improve soils in low-income countries, providing decision tables to guide selection of approaches for different contexts.

Climate change is an enormous challenge to food security and sustainability in agriculture, especially in dry areas like the Barind Tract of Bangladesh. The low resilience of smallholder agricultural systems can be attributed to the production risk associated with the degradation of the soil, a reduction in organic content, and a reduction in groundwater. Against this backdrop, climate-smart agriculture (CSA) has come out as a combined strategy that at the same time increases productivity, builds resilience to changes, and avoids negative effects on the environment. This review paper evaluates the importance of sustainable management of soils in the context of CSA and how it will impact enhancing food security in the Barind region. It is a review of literature that is currently available on the practice of CSA, soil fertility management, and climate adaptation to semi-arid agroecologies. Some of the most important soil management interventions are conservation agriculture, organic amendments, biochar application, agroforestry systems, and moisture conservation. All of these practices aid in better soil structure, higher levels of water retention, and improved nutrient cycling, thus ensuring more stable crop production under climate stress. These interventions are necessary in the Barind Tract that experiences a lot of differences in rainfall and drought, thereby guaranteeing a good yield. These findings indicate that food security directly relates to the health of the soil in crop production, the predictability of agricultural incomes, and coping with climate-related shocks. But CSA practices are still strained by a lack of sufficient financial resources, extension services, and lack of access to climate-resilient technologies. The review highlights the need to support the policy jointly, to develop the capacity, and to invest in the development of sustainable soil and water management systems. Overall, sustainable management of soil in CSA systems is a potential solution to resilient agroecology and increased food security in the Barind region in the face of increased climate variability. Keywords: Sustainable Soil Management, Food Security, Climate-Smart Agriculture, Drought, Barind Tract