Globally, many developing countries are facing silent epidemics of nutritional deficiencies in human beings and animals. The lack of diversity in diet, i.e., cereal-based crops deficient in mineral nutrients is an additional threat to nutritional quality. The present review accounts for the significance of biofortification as a process to enhance the productivity of crops and also an agricultural solution to address the issues of nutritional security. In this endeavor, different innovative and specific biofortification approaches have been discussed for nutrient enrichment of field crops including cereals, pulses, oilseeds and fodder crops. The agronomic approach increases the micronutrient density in crops with soil and foliar application of fertilizers including amendments. The biofortification through conventional breeding approach includes the selection of efficient genotypes, practicing crossing of plants with desirable nutritional traits without sacrificing agricultural and economic productivity. However, the transgenic/biotechnological approach involves the synthesis of transgenes for micronutrient re-translocation between tissues to enhance their bioavailability. Soil microorganisms enhance nutrient content in the rhizosphere through diverse mechanisms such as synthesis, mobilization, transformations and siderophore production which accumulate more minerals in plants. Different sources of micronutrients viz. mineral solutions, chelates and nanoparticles play a pivotal role in the process of biofortification as it regulates the absorption rates and mechanisms in plants. Apart from the quality parameters, biofortification also improved the crop yield to alleviate hidden hunger thus proving to be a sustainable and cost-effective approach. Thus, this review article conveys a message for researchers about the adequate potential of biofortification to increase crop productivity and nourish the crop with additional nutrient content to provide food security and nutritional quality to humans and livestock.

Restoring soil fertility in farming systems is essential to sustain a crop and its productivity. Thus, the present study was conducted to assess the residual effects of the combined application of fertilizers and manures on yield, concentration and uptake of nutrients in wheat under basmati rice-wheat cropping system. The treatments applied in the present study involve T1: control, T2: farmyard manure (15 t ha⁻¹), T3: poultry manure (6 t ha⁻¹), T4: press mud (15 t ha⁻¹), T5: rice straw compost (6 t ha⁻¹), T6: farmyard manure (15 t ha⁻¹) + 50% recommended dose of nitrogen (RDN), T7: poultry manure (6 t ha⁻¹) + 50% RDN, T8: press mud (15 t ha⁻¹) + 50% RDN, T9: rice straw compost (6 t ha⁻¹) + 50% RDN, T10: 75% RDN, T11: farmyard manure (15 t ha¹) + 75% RDN, T12: poultry manure (6 t ha⁻¹) + 75% RDN, T13: press mud (15 t ha⁻¹) + 75% RDN, T14: rice straw compost (6 t ha⁻¹) + 75% RDN, T15: 100% RDN. The residual effects of organic manures significantly improved the growth parameters and yield attributes. Among different residual treatments, the use of farmyard manure + 75% NPK showed maximum plant height (125.2 cm), number of tillers (68.0 m⁻¹), chlorophyll content (45.0) and yield (50.84 q ha⁻¹ for grain and 80.43 q ha⁻¹ for straw, respectively). Additionally, the incorporation of farmyard manure + 75% RDN demonstrated the highest uptake of nitrogen, phosphorus and potassium in grain (7.37, 3.31 and 4.93 g ha⁻¹, respectively) and straw (1.72, 1.05 and 12.63 g ha⁻¹, respectively). The maximum zinc, copper, iron and manganese concentrations were observed to be 32.0, 3.1, 52.1 and 17.6 mg kg⁻¹ in grain and 8.2, 2.1, 374.6 and 20.5 mg kg⁻¹ in straw, respectively. Similarly, the highest uptakes were observed to be 67.6, 15.5, 263.8 and 89.6 g ha⁻¹ in grain and 173.3, 16.8, 3026.9 and 170.6 g ha⁻¹ in straw, respectively. Thus, the integrated application of farmyard manure with 75% RDN could be used to sustain wheat productivity and maintain soil fertility which otherwise deteriorates due to the sole application of inorganic fertilizers.

This paper reports the successful synthesis of magnetic nanocomposite of calcium ferrite with nitrogen doped graphene oxide (CaFe₂O₄-NGO) for the effective removal of Pb(II) ions and photocatalytic degradation of congo red and p-nitrophenol. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) techniques confirmed the presence of NGO and CaFe₂O₄ in the nanocomposite. The Mössbauer studies depicted the presence of paramagnetic doublet and sextet due to presence of CaFe₂O₄ NPs in the nanocomposite. The higher BET surface area in case of CaFe₂O₄-NGO (52.86 m²/g) as compared to CaFe₂O₄ NPs (23.45 m²/g) was ascribed to the effective modulation of surface in the presence of NGO. Adsorption followed the Langmuir model with maximum adsorption capacity of 780.5 mg/g for Pb(II) ions. Photoluminescence spectrum of nanocomposite displayed four-fold decrease in the intensity, as compared to ferrite NPs, thus confirming its high light capturing potential and enhanced photocatalytic activity. The presence of NGO in nanocomposite offered an excellent visible light driven photocatalytic performance. The quenching experiments supported ^●OH and O₂^●− radicals as the main reactive species involved in carrying out the catalytic system. The presence of Pb(II) had synergistic effect on photocatalytic degradation of pollutants. This study highlights the synthesis of CaFe₂O₄-NGO nanocomposite as an efficient adsorbent and photocatalyst for remediating pollutants.

Micronutrient deficiency is a major constraint for the growth, yield and nutritional quality of cowpea which results in nutritional disorders in humans. Micronutrients including molybdenum (Mo), iron (Fe) and zinc (Zn) play a pivotal role in crop nutrition, and their role in different metabolic processes in crops has been highlighted. In order to increase the nutritional quality of cowpea, a field experiment was conducted for two years in which the effect of Mo along with iron (Fe) and zinc (Zn) on productivity, nitrogen and micronutrient uptake, root length and the number of nodules in cowpea cultivation was investigated. It was found that the foliar application of Fe and Zn and their interaction with Mo application through seed priming as well as soil application displayed increased yield, nutrient concentration, uptake and growth parameters which helped to enhance the nutritional quality of cowpea for consumption by the human population. The results of the above experiments revealed that among all the treatments, the soil application of Mo combined with the foliar application of 0.5% each of FeSO₄·7H₂O and ZnSO₄·7H₂O (M₂F₃ treatment) enhanced the grain and stover yield of cowpea, exhibiting maximum values of 1402 and 6104.7 kg ha⁻¹, respectively. Again, the M₂F₃ treatment resulted in higher Zn, Fe and Mo concentrations in the grain (17.07, 109.3 and 30.26 mg kg⁻¹, respectively) and stover (17.99, 132.7 and 31.22 mg kg⁻¹, respectively) of cowpea. Uptake of Zn, Fe and Mo by the grain (25.23, 153.3 and 42.46 g ha⁻¹, respectively) as well as the stover (104.2, 809.9 and 190.6 g ha⁻¹, respectively) was found to be maximum for the M₂F₃ treatment. The root length (30.5 cm), number of nodules per plant (73.0) and N uptake in grain and stover (55.39 and 46.15 kg ha⁻¹) were also higher for this treatment. Overall, soil application of Mo along with the foliar application of FeSO₄·7H₂O (0.5%) and ZnSO₄·7H₂O (0.5%) significantly improved yield outcomes, concentration, uptake, root length, nodules plant⁻¹ and N uptake of cowpea to alleviate the micronutrient deficiency.

The nutritional value of Glycine max L. (soybean) and its yield potential for improving sustainability of agricultural systems has resulted into its increased production. Soybean crop has potential to replace the rice crop in the rice-wheat cropping system. However, the crop has shown high sensitivity towards iron (Fe) deficiency, and thus recorded major yield and nutritional quality losses. Thus, a three-year field experiment was planned to compare the impact of the application rate (0.5% and 1.0%) and number of sprays of FeSO₄ on yield, Fe nutrition, and economic outcomes of soybeans. The Fe application posed a beneficial impact on the studied parameters due to an increase in enzymatic activity of Fe-containing enzymes. Among various treatments, maximum increase in grain and straw yield (3064 and 9341 kg ha⁻¹, respectively) was obtained with 0.5% FeSO₄ application at 30, 60, and 90 DAS over the control (2397 and 6894 kg ha⁻¹, respectively). Similar results were attained for grain Fe concentration (69.9 mg kg⁻¹) and Fe uptake in grain and straw (214 and 9088 g ha⁻¹, respectively). The results were statistically non-significant, with the treatment in which 0.5% FeSO₄ was applied at 30 and 60 DAS. The economic returns of soybean cultivation were also highest with 0.5% FeSO₄ application at 30, 60, and 90 DAS with highest benefit; the cost (3.02) followed by treatment in which 0.5% FeSO₄ was applied at 30 and 60 DAS. Thus, 0.5% FeSO₄ application at 30, 60, and 90 DAS can be recommended for soybeans grown on sandy loam soil followed by 0.5% FeSO₄ application at 30and 60 DAS to harness maximum yield, Fe concentration, and profitability.