The agricultural sector is a vital source of human well-being that provides the necessities of daily life. A variety of farming systems are utilized in agriculture, such as a wide range of tillage options, no-till, agroforestry, precision farming, organic farming, cover cropping, crop rotations, etc. Each of these farming systems has unique challenges, and nanotechnology has successfully improved on many of them. Agricultural applications of nanotechnology include nanofertilizers, nanopesticides, nanosensors, nanobiotechnology, and nanoremediation. This study focuses on the application of nano-farming technologies to different farming systems. Suggested practices include nano improvement of soil quality, crop nano-protection under biotic stress, nanoremediation of polluted soil and water environments, nanomanagement of agro-wastes, nano-agrochemicals, nano-precision farming, and nanobiotechnology for modern farming. This review also addresses expected problems that may occur due to over application of nanomaterials to farming systems, such as nanopollution and nanotoxicity of agroecosystem compartments. Several dimensions are emphasized in this study, such as green energy, sustainable development, the circular bioeconomy, land biodegradation, pollution, and the one health approach, as essential for the global goals of sustainable development. Nanofarming presents both benefits and obstacles to human life. The exact balance between these benefits and challenges needs more study.

Soil salinity is a serious global problem that threatens a high percentage of the global soils. Salinity stress can create ionic, oxidative, and osmotic stress, along with hormonal imbalances, in stressful plants. This kind of stress was investigated on agricultural productivity at different levels, starting in vitro (plant tissue culture), through hydroponics, pots, and field conditions. Several approaches were studied for managing salinity stress, including using traditional materials (e.g., gypsum, sulfur), organic amendments (e.g., compost, biochar, chitosan), and applied manufactured or engineered nanomaterials (NMs). Application of nanomaterials for ameliorating salinity stress has gained great attention due to their high efficiency, eco-friendliness, and non-toxicity, especially biological nanomaterials. The application of NMs did not only support growing stressful plants under salinity stress but also increased the yield of crops, provided an economically feasible nutrient management approach, and was environmentally robust for sustainable crop productivity. Nano-management of salinity may involve applying traditional nano-amendments, biological nanomaterials, nano-enabled nutrients, nano-organic amendments, derived smart nanostructures, and nano-tolerant plant cultivars. Producing different plant cultivars that are tolerant to salinity can be achieved using conventional breeding and plantomics technologies. In addition to the large-scale use of nanomaterials, there is an urgent need to address and treat nanotoxicity. This study aims to contribute to this growing area of research by exploring different approaches for nano-management of current practices under salinity stress under field and in vitro conditions. This study also raises many questions regarding the expected interaction between the toxic effects of salinity and NMs under such conditions. This includes whether this interaction acts positively or negatively on the cultivated plants and soil biological activity, or what regulatory ecotoxicity tests and protocols should be used in research.

Tellurium (Te) is the heaviest stable chalcogen and is a rare element in Earth’s crust (one to five ppb). It was discovered in gold ore from mines in Kleinschlatten near the present-day city of Zlatna, Romania. Industrial and other applications of Te focus on its inorganic forms. Tellurium can be toxic to animals and humans at low doses. Chronic tellurium poisoning endangers the kidney, liver, and nervous system. However, Te can be effective against bacteria and is able to destroy cancer cells. Tellurium can also be used to develop redox modulators and enzyme inhibitors. Soluble salts that contain Te had a role as therapeutic and antimicrobial agents before the advent of antibiotics. The pharmaceutical use of Te is not widespread due to the narrow margin between beneficial and toxic doses, but there are differences between the measure of toxicity based on the Te form. Nano-tellurium (Te-NPs) has several applications: it can act as an adsorptive agent to remove pollutants, and it can be used in antibacterial coating, photo-catalysis for the degradation of dyes, and conductive electronic materials. Nano-sized Te particles are the most promising and can be produced in both chemical and biological ways. Safety assessments are essential to determine the potential risks and benefits of using Te compounds in various applications. Future challenges and directions in developing nano-materials, nano-alloys, and nano-structures based on Te are still open to debate.

The relationship between agriculture and food is very close. It is impossible to produce adequate crops for global food security without proper farm management. Farming practices represent direct and indirect controlling factors in terms of global food security. Farming management practices influence agro-food production from seed germination through to the post-harvest treatments. Nano-farming utilizes nanotechnologies for agricultural food production. This review covers four key components of nano-farming: nano-mushroom production, protein-based nanoparticles, nano-nutrients, and nanofibers. This provides a comprehensive overview of the potential applications of nanotechnology in agriculture. The role of these components will be discussed in relation to the challenges faced and solutions required to achieve sustainable agricultural production. Edible mushrooms are important to food security because they are a nutritious food source and can produce nanoparticles that can be used in the production of other food sources. Protein-based nanoparticles have considerable potential in the delivery of bioactives as carriers and other applications. Nano-nutrients (mainly nano-selenium, nano-tellurium and carbon nanodots) have crucial impacts on the nutrient status of plant-based foods. Carbon nanodots and other carbon-based nanomaterials have the potential to influence agricultural crops positively. There are promising applications of nanofibers in food packaging, safety and processing. However, further research is needed to understand the impacts and potential risks of nanomaterials in the food production system.

Using seleno-compounds and telluric compounds is a practical approach for developing solutions against drug-resistant bacterial infections and malignancies. It will accelerate the search for novel treatments or adjuvants for existing therapies. Selenium and tellurium nanospheres can be produced by lactic acid bacteria. The bacteria can differentiate the selenium and tellurium when the medium contains both selenite and tellurite. Therefore, our question in this study was the following: are they making alloys from the selenium and tellurium and what will be the composition, color, and shape of the nanoparticles? We used a simple microbial synthesis to produce nanoselenium, nanotellurium, and their alloys from sodium selenite and sodium tellurite using Lactobacillus casei. This bacterium produced red spherical amorphous elemental selenium nanospheres with a diameter of 206 ± 33 nm from selenite and amorphous black nanorods with a length of 176 ± 32 nm and a cross-section of 62 ± 13 nm from tellurite. If the initial medium contains a mixture of selenite and tellurite, the resulting nanoparticles will contain selenium and tellurium in the same ratios in the alloy as in the medium. This proves that Lactobacillus casei cannot distinguish between selenite and tellurite. The shape of the nanoparticles varies from spherical to rod-shaped, depending on the ratio of selenium and tellurium. The color of nanomaterials ranges from red to black, depending on the percentage of selenium and tellurium. These nanomaterials could be good candidates in the pharmaceutical industry due to their antipathogenic and anticarcinogenic properties.

Natural resources including water, energy, and food have an increase in demand due to the global population increases. The sustainable management of these resources is an urgent global issue. These resources combined in a very vital nexus are called the water–energy–food (WEF) nexus. The field of nanotechnology offers promising solutions to overcome several problems in the WEF nexus. This review is the first report that focuses on the suggested applications of nanofibers in the WEF sectors. An economic value of nanofibers in WEF sectors was confirmed, which was mainly successfully applied for producing clean water, sustainable energy, and safe food. Biotechnological solutions of nanofibers include various activities in water, energy, and food industries. These activities may include the production of fresh water and wastewater treatment, producing, converting, and storing energy, and different activities in the food sector. Furthermore, microbial applications of nanofibers in the biomedicine sector, and the most important biotechnological approaches, mainly plant tissue culture, are the specific focus of the current study. Applying nanofibers in the field of plant tissue culture is a promising approach because these nanofibers can prevent any microbial contamination under in vitro conditions, but the loss of media by evaporation is the main challenge in this application. The main challenges of nanofiber production and application depend on the type of nanofibers and their application. Different sectors are related to almost all activities in our life; however, enormous open questions still need to be answered, especially the green approach that can be used to solve the accumulative problems in those sectors. The need for research on integrated systems is also urgent in the nexus of WEF under the umbrella of environmental sustainability, global climate change, and the concept of one’s health.