Micronutrients in Food Production: What Can We Learn from Natural Ecosystems?

India's biogeochemical capacity to attain food security and remediate climate

In order to supply wholesome food and slow down climate change, this paper covers India's agrogeological resources. The soils are the result of the weathering of rocks with ages ranging from more than a billion years to the most recent Holocene. Because they are severely deficient in vital minerals, many soils have low agricultural production. In addition to helping to fertilise soils, reduce atmospheric carbon dioxide levels, and stop the acidification of the Indian Ocean, rock powder weathering and biochar have significant positive effects on the productivity of Indian soils. The nutrient density of food is also increased which improves health and lowers the demand for and cost of medical treatment. Remineralization may help to solve Indian soil issues including soil infertility and texture. To improve soil and plant nutrition, dusts of carbonate, basic, and ultrabasic rocks are readily available at mining sites in India combined with biochar. Adding different grain sizes to the soil helps improve the texture of the soil. Silicate and carbonate rock powders enhance soil structure by promoting the creation of soil organic matter and fostering the growth of advantageous microbial communities. These processes offer a low-cost method of remineralizing soils with important macro- and micronutrients. For each significant soil/crop/climate system, an optimised application of India's rock powder resources must be determined through a national research and development programme. India's capacity to adapt to the mounting challenges of population expansion and climate change would be significantly improved by the findings of this study programme.

Biofortification revisited: Addressing the role of beneficial soil microbes for enhancing trace elements concentration in staple crops

Trace element deficiency is a pervasive issue contributing to malnutrition on a global scale. The primary cause of this hidden hunger is related to low dietary intake of essential trace elements, which is highly prevalent in numerous regions across the world. To address deficiency diseases in humans, fortification of staple crops with vital trace elements has emerged as a viable solution. Current methods for fortifying crops encompass chemical amendments, genetic breeding, and transgenic approaches, yet these approaches possess certain limitations, constraining their agricultural application. In contrast, fortifying staple crops through the utilization of soil-beneficial microbes has emerged as a promising and economically feasible approach to enhance trace element content in crops. A specific subset of these beneficial soil microbes, referred to as plant growth-promoting microbes, have demonstrated their ability to influence the interactions between plants, soil, and minerals. These microbes facilitate the transport of essential soil minerals, such as zinc, iron, and selenium, into plants, offering the potential for the development of tailored bioinoculants that can enhance the nutritional quality of cereals, pulses, and vegetable crops. Nevertheless, further research efforts are necessary to comprehensively understand the molecular mechanisms underlying the uptake, transport, and augmentation of trace element concentrations in staple crops. By delving deeper into these mechanisms, customized bioinoculants of soil-beneficial microbes can be developed to serve as highly effective strategies in combating trace element deficiency and promoting global nutritional well-being.

Rhizofiltration of combined arsenic-fluoride or lead-fluoride polluted water using common aquatic plants and use of the 'clean' water for alleviating combined xenobiotic toxicity in a sensitive rice variety

Groundwater co-contamination with toxic pollutants like arsenic-fluoride or lead-fluoride is a serious threat for safe rice cultivation, since major stretches of land, involved in cultivation of this staple food crop are presently experiencing severe endemic pollution from these xenobiotic combinations. Preliminary investigations established that the combined pollutants together exerted more phytotoxicity in the widely cultivated indica rice variety Khitish, compared with that exerted by the individual contaminants. Thus, an ecologically sustainable and economically viable phytoremediative strategy was designed where three aquatic plants, viz., Azolla (water fern), Pistia (water lettuce) and Eichhornia (water hyacinth) (commonly located across the co-polluted regions) were tested for their ability to rhizofiltrate the water samples that had been polluted with arsenic-fluoride or lead-fluoride. Water lettuce exhibited the highest ability to 'clean' both arsenic-fluoride and lead-fluoride polluted water due to its capacity of efficient phytoextraction and phytostabilization. Irrigation of Khitish seedlings with this de-polluted water appreciably reduced malondialdehyde formation, electrolyte leakage and irreversible protein carbonylation due to suppression in NADPH oxidase activity and reactive oxygen species production, compared with those in sets grown with non-treated, arsenic-fluoride or lead-fluoride contaminated water. Oxidative injuries, cytotoxic methylglyoxal synthesis and inhibition of biomass growth were ameliorated, and chlorophyll synthesis and Hill activity were increased due to reduced bioaccumulation of xenobiotics, along with the improved uptake of vital micronutrients like iron, copper and nickel. Overall, the current investigation illustrated a cheap, farmer-friendly blueprint which could be easily promulgated to ensure safe rice cultivation even across territories that are severely co-polluted with the mixed contaminants.