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.

Department of Agronomy Bangladesh Wheat and Maize Research Institute Dinajpur 5200 Bangladesh

Department of Agronomy Indian Agricultural Research Institute New Delhi 110012 India

Department of Biology College of Science Taif University P O Box 11099 Taif 21944 Saudi Arabia

Department of Botany and Plant Physiology Faculty of Agrobiology Food and Natural Resources Czech University of Life Sciences Prague Kamycka 129 165 00 Prague Czech Republic

Department of Plant Physiology Slovak University of Agriculture Tr A Hlinku 2 949 01 Nitra Slovakia

Department of Soil Science Punjab Agricultural University Ludhiana 141004 India

Department of Water Resources and Environmental Engineering Faculty of Horticulture and Landscape Engineering Slovak University of Agriculture Nitra Tr A Hlinku 2 949 01 Nitra Slovakia

ICA Indian Institute of Soil Science Bhopal 462038 India

See more in PubMed

Huang S., Wang P., Yamaji N., Ma J.F. Plant nutrition for human nutrition: Hints from rice research and future perspectives. Mol. Plant. 2020;13:825–835. doi: 10.1016/j.molp.2020.05.007. PubMed DOI

Kennedy E., Jafari A., Stamoulis K.G., Callens K. The first programme food and nutrition security, impact, resilience, sustainability and transformation: Review and future directions. Glob. Food Sec. 2020;26:100422. doi: 10.1016/j.gfs.2020.100422. PubMed DOI PMC

Maertens M., Velde K.V. Contract-farming in staple food chains: The case of rice in Benin. World Dev. 2017;95:73–87. doi: 10.1016/j.worlddev.2017.02.011. DOI

Klikocka H., Marks M. Sulphur and nitrogen fertilization as a potential means of agronomic biofortification to improve the content and uptake of microelements in spring wheat grain DM. J. Chem. 2018;2018:9326820. doi: 10.1155/2018/9326820. DOI

Steur H.D., Mehta S., Gellynck X., Finkelstein J.L. GM biofortified crops: Potential effects on targeting the micronutrient intake gap in human populations. Curr. Opin. Biotechnol. 2017;44:181–188. doi: 10.1016/j.copbio.2017.02.003. PubMed DOI

Cakmak I., Kutman U.B. Agronomic biofortification of cereals with zinc: A review. Eur. J. Soil Sci. 2017;69:172–180. doi: 10.1111/ejss.12437. DOI

Connorton J.M., Balk J. Iron biofortification of staple crops: Lessons and challenges in plant genetics. Plant Cell Physiol. 2019;60:1447–1456. doi: 10.1093/pcp/pcz079. PubMed DOI PMC

Ligowe I.S., Bailey E.H., Young S.D., Ander E.L., Kabambe V., Chilimba A.D., Lark R.M., Nalivata P.C. Agronomic iodine biofortification of leafy vegetables grown in Vertisols, Oxisols and Alfisols. Environ. Geochem. Health. 2021;43:361–374. doi: 10.1007/s10653-020-00714-z. PubMed DOI PMC

Zheng X., Giuliano G., Al-Babili S. Carotenoid biofortification in crop plants: Citius, altius, forties. Biochim. Biophys. Acta Mol. Cell Biol. Lipids. 2020;1865:158664. doi: 10.1016/j.bbalip.2020.158664. PubMed DOI

Saeid A., Patel A., Jastrzębska M., Korczyński M. Food biofortification. J. Chem. 2019;2019:5718426. doi: 10.1155/2019/5718426. DOI

Górniak W., Cholewińska P., Konkol D. Feed additives produced on the basis of organic forms of micronutrients as a means of biofortification of food of animal origin. J. Chem. 2018;2018:8084127. doi: 10.1155/2018/8084127. DOI

Zulfiqar F., Navarro M., Ashraf M., Akram N.A., Munné-Bosch S. Nanofertilizer use for sustainable agriculture: Advantages and limitations. Plant Sci. 2019;289:110270. doi: 10.1016/j.plantsci.2019.110270. PubMed DOI

Torre-Roche D.L.R., Cantu J., Tamez C., Zuverza-Mena N., Hamdi H., Adisa I.O., Elmer W., Torresdey J.G., White J.C. Seed biofortification by engineered nanomaterials: A pathway to alleviate malnutrition? J. Agric. Food Chem. 2020;68:12189–12202. doi: 10.1021/acs.jafc.0c04881. PubMed DOI

Kaur T., Rana K.L., Kour D., Sheikh I., Yadav N., Kumar V., Yadav A.N., Dhaliwal H.S., Saxena A.K. New and Future Developments in Microbial Biotechnology and Bioengineering. Elsevier; Amsterdam, The Netherlands: 2020. Microbe-mediated biofortification for micronutrients: Present status and future challenges; pp. 1–17.

Sillanpää M. Soils Bulletin. FAO; Rome, Italy: 1990. Micronutrient assessment at country level: An international study; p. 208. No. 63.

Lešková A., Giehl R.F.H., Hartmann A., Fargašová A., von Wirén N. Heavy metals induce iron deficiency responses at different hierarchic and regulatory levels. Plant Physiol. 2017;174:1648–1668. doi: 10.1104/pp.16.01916. PubMed DOI PMC

Singh M.V. Evaluation of micronutrient status in different agroecological zones of India. Fertil. News. 2001;46:25–42.

Singh A.P., Singh M.V., Sakal R., Chaudhary V.C. Boron nutrition of crops and soils of Bihar. Tech. Bull. 2006;6:1–80.

Bhupalraj G., Patnaik M.C., Khadke K.M. Molybdenum status in soils of Andhra Pradesh. AICRP Micro Second. Nutr. Soils Plants Pradesh. 2002;36:1–87.

Shaw D.J. World Food Security. Palgrave Macmillan; London, UK: 2007. World Food Conference 1974.

Ohanenye I.C., Emenike C.U., Mensi A., Medina-Godoy S., Jin J., Ahmed T., Sun X., Udenigwe C.C. Food fortification technologies: Influence on iron, zinc and vitamin A bioavailability and potential implications on micronutrient deficiency in sub-Saharan Africa. Sci. Afr. 2021;11:e00667. doi: 10.1016/j.sciaf.2020.e00667. DOI

Stein A.J., Qaim M. The human and economic cost of hidden hunger. Food Nutr. Bull. 2007;28:125–134. doi: 10.1177/156482650702800201. PubMed DOI

India State-Level Disease Burden Initiative Collaborators Nations within a nation: Variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study. Lancet. 2017;390:2437–2460. doi: 10.1016/S0140-6736(17)32804-0. PubMed DOI PMC

West K.P. Extent of vitamin A deficiency among preschool children and women of reproductive age. J. Nutr. 2002;132:2857S–2866S. doi: 10.1093/jn/132.9.2857S. PubMed DOI

Cook R. World Cattle Inventory. 2020. [(accessed on 31 January 2020)]. Available online: www.beef2live.com.

Earagariyanna M.Y., Venkayala J., Kammardi S., Sriramaiah M. Fodder resource management in India-A critical analysis. Int. J. Livest. Res. 2020;7:14–22. doi: 10.5455/ijlr.20170513095912. DOI

McDowell L.R. Minerals in Animal and Human Nutrition. 2nd ed. Elsevier Science BV; Amsterdam, The Netherlands: 2003.

Suttle N.F. Copper imbalances in ruminants and humans: Unexpected common ground. Adv. Nutr. 2012;3:666–674. doi: 10.3945/an.112.002220. PubMed DOI PMC

Lean M.E. Principles of human nutrition. Medicine. 2019;47:140–144. doi: 10.1016/j.mpmed.2018.12.014. DOI

Rosa-Sibakov N., Poutanen K., Micard V. How does wheat grain, bran and aleurone structure impact their nutritional and technological properties? Trends Food Sci. Technol. 2015;41:118–134. doi: 10.1016/j.tifs.2014.10.003. DOI

Nuss E.T., Tanumihardjo S.A. Maize: A paramount staple crop in the context of global nutrition. Food Soc. Food Saf. 2010;9:417–436. doi: 10.1111/j.1541-4337.2010.00117.x. PubMed DOI

Callens T., del Castello R., Baratelli M., Xipsiti M., Navarro D.K. The International Year of Pulses. FAO; Rome, Italy: 2019. p. 40. Final Report.

Brueck H., Lammel J. Impact of fertilizer N application on the grey water footprint of winter wheat in a NW-European temperate climate. Water. 2016;8:356. doi: 10.3390/w8080356. DOI

Rebello C.J., Greenway F.L., Finley J.W. Whole grains and pulses: A comparison of the nutritional and health benefits. J Agric. Food Chem. 2014;62:7029–7049. doi: 10.1021/jf500932z. PubMed DOI

Venkidasamy B., Selvaraj D., Nile A.S., Ramalingam S., Kai G., Nile S.H. Indian pulses: A review on nutritional, functional and biochemical properties with future perspectives. Trends Food Sci. Technol. 2019;88:228–242. doi: 10.1016/j.tifs.2019.03.012. DOI

Zafar S., Li Y.L., Li N.N., Zhu K.M., Tan X.L. Recent advances in enhancement of oil content in oilseed crops. J. Biotechnol. 2019;301:35–44. doi: 10.1016/j.jbiotec.2019.05.307. PubMed DOI

Kowalska G., Kowalski R., Hawlena J., Rowiński R. Seeds of oilseed rape as an alternative source of protein and mineral. J. Elementol. 2020;25:513–522. doi: 10.5601/jelem.2019.24.3.1893. DOI

Száková J., Praus L., Tremlová J., Kulhánek M., Tlustoš P. Efficiency of foliar selenium application on oilseed rape (Brassica napus L.) as influenced by rainfall and soil characteristics. Arch. Agron. Soil Sci. 2017;63:1240–1254. doi: 10.1080/03650340.2016.1275581. DOI

López-Alonso M. Trace minerals and livestock: Not too much not too little. ISRN Vet. Sci. 2012;2012:704825. doi: 10.5402/2012/704825. PubMed DOI PMC

Jadhav P.V., Magar S., Thakur P., Moharil M.P., Yadav H., Mandlik R. Advances in Agri-Food Biotechnology. Springer Nature; Singapore: 2020. Biofortified fodder crops: An approach to eradicate hidden hunger.

Boller B., Greene S.L. Fodder Crops and Amenity Grasses. Springer; New York, NY, USA: 2010. Genetic resources; pp. 13–37.

Humphreys M.W., O’Donovan S.A., Farrell M.S., Gay A.P., Kingston-Smith A.H. The potential of novel Festulolium (2n = 4x = 28) hybrids as productive, nutrient-use-efficient fodder for ruminants. Food Energy Sec. 2014;3:98–110. doi: 10.1002/fes3.50. DOI

Cabral G.B., Carneiro V.T., Rossi M.L., da Silva J.P., Martinelli A.P., Dusi D.M. Plant regeneration from embryogenic callus and cell suspensions of Brachiaria brizantha. In Vitro Cell. Dev. Biol. Plant. 2015;51:369–377. doi: 10.1007/s11627-015-9690-0. DOI

Badenhorst P., Panter S., Palanisamy R., Georges S., Smith K., Mouradov A., Mason J., Spangenberg G. Molecular breeding of transgenic perennial ryegrass (Lolium perenne L.) with altered fructan biosynthesis through the expression of fructosyltransferases. Mol. Breed. 2018;38:21. doi: 10.1007/s11032-018-0776-3. DOI

Gao R., Feyissa B.A., Croft M., Hannoufa A. Gene editing by CRISPR/Cas9 in the obligatory outcrossing Medicago sativa. Planta. 2018;247:1043–1050. doi: 10.1007/s00425-018-2866-1. PubMed DOI

Kaur J., Bhatti D.S., Goyal M. Influence of copper application on forage yield and quality of oats fodder in copper deficient soils. Indian J. Anim. Nutr. 2015;32:290–294.

Sandhu A., Dhaliwal S.S., Shukla A.K., Sharma V., Singh R. Fodder quality improvement and enrichment of oats with Cu through biofortification: A technique to reduce animal malnutrition. J. Plant Nutr. 2020;43:1378–1389. doi: 10.1080/01904167.2020.1739291. DOI

Kumar D., Dhaliwal S.S., Naresh R.K., Salaria A. Agronomic biofortification of paddy through nitrogen, zinc and iron fertilization: A review. Int. J. Curr. Microbiol. Appl. Sci. 2018;7:2942–2953. doi: 10.20546/ijcmas.2018.707.344. DOI

Dhaliwal S.S., Manchanda J.S. Critical level of Boron in Typic Ustrochrepts for predicting response of mungbean (Phaseolus aureus L.) to boron application. Indian J. Ecol. 2009;36:22–27.

Dhaliwal S.S., Sadana U.S., Khurana M.P., Sidhu S.S. Enrichment of wheat grains with Zn through ferti-fortification. Indian J. Fertil. 2012;8:48–55.

Ram H., Sohu V.S., Cakmak I., Singh K., Buttar G.S., Sodhi G.P.S., Gill H.S., Bhagat I., Singh P., Dhaliwal S.S., et al. Agronomic fortification of rice and wheat grains with zinc for nutritional security. Curr. Sci. 2015;129:1171–1176. doi: 10.18520/cs/v109/i6/1171-1176. DOI

Manzeke M.G., Mtambanengwe F., Nezomba H., Watts M.J., Broadley M.R., Mapfumo P. Zinc fertilization increases productivity and grain nutritional quality of cowpea (Vigna unguiculata [L.] Walp.) under integrated soil fertility management. Field Crop. Res. 2017;213:231–244. doi: 10.1016/j.fcr.2017.08.010. DOI

Rasheed N., Maqsood M.A., Aziz T., Jabbar A. Characterizing lentil germplasm for zinc biofortification and high grain output. J. Soil Sci. Plant Nutr. 2020;20:1336–1349. doi: 10.1007/s42729-020-00216-y. DOI

Dai H., Wei S., Twardowska I. Biofortification of soybean (Glycine max L.) with Se and Zn, and enhancing its physiological functions by spiking these elements to soil during flowering phase. Sci. Total Environ. 2020;740:139648. doi: 10.1016/j.scitotenv.2020.139648. PubMed DOI

Dhaliwal S.S., Sadana U.S., Manchanda J.S., Dhadli H.S. Biofortification of wheat grains with zinc (Zn) and iron (Fe) in typic Ustochrept soils of Punjab. Indian J. Fertil. 2009;5:13–16.

Dhaliwal S.S., Sadana U.S., Khurana M.P.S., Dhadli H.S., Manchanda J.S. Enrichment of paddy grains (Oryza sativa L.) with zinc and iron through ferti-fortification. Indian J. Fertil. 2010;6:28–35.

Dhaliwal S.S., Sadana U.S., Manchanda J.S. Relevance and essentiality of ferti-fortification of wheat grains with manganese and copper. Indian J. Fertil. 2011;7:48–55.

Singh P., Dhaliwal S.S., Sadana U.S. Iron enrichment of paddy grains through ferti-fortification. J. Res. (Punjab Agric. Univ.) 2013;50:32–38.

Dhaliwal S.S., Sadana U.S., Manchanda J.S., Khurana M.P.S., Shukla A.K. Differential response of maize cultivars to iron (Fe) applied through ferti-fortification. Indian J. Fertil. 2013;9:52–57.

Ullah M., Farooq A., Rehman M.S., Arshad H., Shoukat A., Nadeem A., Nawaz A., Wakeel A., Nadeem F. Manganese nutrition improves the productivity and grain biofortification of bread wheat in alkaline calcareous soil. Exp. Agric. 2018;54:744–754. doi: 10.1017/S0014479717000369. DOI

Kumar D., Dhaliwal S.S., Uppal R.S., Ram H. Influence of nitrogen, zinc and iron fertilizer on growth parameters and yield of Parmal rice in transplanted condition. Indian J. Ecol. 2016;43:115–118.

Singh V.P., Singh G., Dhaliwal S.S. Agronomic biofortification of chickpea with zinc and iron through application of zinc and urea. Commun. Soil Sci. Plant Anal. 2019;50:1864–1877.

Dhaliwal S.S., Sandhu A.S., Shukla A.K., Sharma V., Kumar B., Singh R. Bio-fortification of oats fodder through zinc enrichment to reduce animal malnutrition. J. Agric. Sci. Technol. A. 2020;10:98–108.

Kumar B., Dhaliwal S.S. Zinc biofortification of dualpurpose cowpea [Vigna unguiculata (L.) Walp] for enhancing the productivity and nutritional quality in a semi-arid regions of India. Arch. Agron. Soil Sci. 2021 doi: 10.1080/03650340.2020.1868040. DOI

Farooq M., Basra S.M.A., Tabassum R., Afzal I. Enhancing the performance of direct seeded fine rice by seed priming. Plant Prod. Sci. 2006;9:446–456. doi: 10.1626/pps.9.446. DOI

Farooq M., Cheema Z.A., Wahid A. Seed priming with boron improves growth and yield of fine grain aromatic rice. Plant Growth Regul. 2012;68:189–201.

Rehman M., Muhammad F., Muhammad N., Ahmad N., Babar S. Seed priming of Zn with endophytic bacteria improves the productivity and grain biofortification of bread wheat. Eur. J. Agron. 2018;94:98–107. doi: 10.1016/j.eja.2018.01.017. DOI

Reis C.A., Pavia S., Lima-Brito I., Eduardo J. Influence of seed priming with iron and/or zinc in the nucleolar activity and protein content of bread wheat. Protoplasma. 2019;256:763–775. PubMed

Rehman M., Faroo Z.A. Zinc seed coating improves the growth, grain yield and grain biofortification of bread wheat. Acta Physiol. Plant. 2016;38:238. doi: 10.1007/s11738-016-2250-3. DOI

Rehman M., Farooq Z.A. Boron application through seed coating improves the water relations, panicle fertility, kernel yield, and biofortification of fine grain aromatic rice. Acta Physiol. Plant. 2013;35:411–418. doi: 10.1007/s11738-012-1083-y. DOI

Selim M.M. Introduction to the integrated nutrient management strategies and their contribution to yield and soil properties. Int. J. Agron. 2020;2:2821678. doi: 10.1155/2020/2821678. DOI

Padbhushan R., Sharma S., Kumar U., Rana D.S., Kohli A., Kaviraj M., Parmar B., Kumar R., Annapurna K., Sinha A.K., et al. Meta-analysis approach to measure the effect of integrated nutrient management on crop performance, microbial activity, and carbon stocks in indian soils. Front. Environ. Sci. 2021;9:724702. doi: 10.3389/fenvs.2021.724702. DOI

Barman M., Shukla L.M., Datta S., Rattan R.K. Effect of applied lime and boron on the availability of nutrients in an acid soil. J. Plant Nutr. 2014;37:357–373. doi: 10.1080/01904167.2013.859698. DOI

Soltani S.M., Mohamed M.H., Abdol W.S., Sharifah K.S.M., Mohammad A.H. Rice growth improvement and grains bio-fortification through lime and zinc application in zinc deficit tropical acid sulphate soils. Chem. Speciat. Bioavailab. 2016;28:152–162. doi: 10.1080/09542299.2016.1198989. DOI

Ramzani P.M.A., Khalid M., Naveed M., Ahmad R., Shahid M. Iron biofortification of wheat grains through integrated use of organic and chemical fertilizers in pH affected calcareous soil. Plant Physiol. Biochem. 2016;104:284–293. doi: 10.1016/j.plaphy.2016.04.053. PubMed DOI

Tavakkoli E., Uddin S., Rengasamy P., McDonald G.K. Field applications of gypsum reduce pH and improve soil C in highly alkaline soils in southern Australia’s dryland cropping region. Soil Use Manag. 2022;38:466–477. doi: 10.1111/sum.12756. DOI

Nagabovanalli B.P., Prabhudev D., Shruthi C.T., Shrenivas A. Performance of slag-based gypsum on maize yield and available soil nutrients over commercial gypsum under acidic and neutral soil. Commun. Soil Sci. Plant Anal. 2020;51:1780–1798.

Farooq M., Ullah A., Usman M., Siddique K.H.M. Application of zinc and biochar help to mitigate cadmium stress in bread wheat raised from seeds with high intrinsic zinc. Chemosphere. 2020;260:127652. doi: 10.1016/j.chemosphere.2020.127652. PubMed DOI

Khum-in V., Suk-in J., In-ai P., Piaowan K., Phaimisap Y., Supanpaiboon W., Phenrat T. Combining biochar and zerovalent iron (BZVI) as a paddy field soil amendment for heavy cadmium (Cd) contamination decreases Cd but increases zinc and iron concentrations in rice grains: A field-scale evaluation. Process Saf. Environ. Prot. 2020;141:222–233. doi: 10.1016/j.psep.2020.05.008. DOI

Kalembasa D., Malinowska E. Bioaccumulation of zinc under the influence of sewage sludge and liming and its speciation in soil. Fresen Environ. Bull. 2013;22:3359–3369.

Malinowska E. The effects of soil liming and sewage sludge application on dynamics of copper fractions and total copper concentration. Environ. Monitor. Assess. 2016;188:597. doi: 10.1007/s10661-016-5609-4. PubMed DOI PMC

Dwivedi R., Srivastva P.C. Effect of zinc sulphate application and the cyclic incorporation of cereal straw on yields, the tissue concentration and uptake of Zn by crops and availability of Zn in soil under rice–wheat rotation. Int. J. Recycl. Org. Waste Agric. 2014;3:53. doi: 10.1007/s40093-014-0053-3. DOI

Khoshgoftarmanesh A.H., Norouzi M., Afyuni M., Schulin R. Zinc biofortification of wheat through preceding crop residue incorporation into the soil. Eur. J. Agron. 2017;89:131–139. doi: 10.1016/j.eja.2017.05.006. DOI

Behera S.B., Shukla A.K., Brahma S., Dwivedi R., Lakaria B.L. Lime and zinc application influence soil zinc availability, dry matter yield and zinc uptake by maize grown on Alfisols. SOIL Discuss. 2016 doi: 10.5194/soil-2016-41. DOI

Schweizer S.A., Seitz B., van der Heijden M.G.A., Schulin R., Tandy S. Impact of organic and conventional farming systems on wheat grain uptake and soil bioavailability of zinc and cadmium. Sci. Total Environ. 2018;639:608–616. doi: 10.1016/j.scitotenv.2018.05.187. PubMed DOI

Nayak B.K., Adhikary S., Pattnaik M., Pal A.K. Effect of Sulphur and zinc with combination of FYM on yield and uptake of nutrients in Mustard (Brassica juncea (L.) under Alfisols of Odisha. J. Pharmacog. Phytochem. 2020;9:2310–2313.

Ulm F., Avelar D., Hobson P., Penha-Lopes G., Dias T., Máguas C., Cruz C. Sustainable urban agriculture using compost and an open-pollinated maize variety. J. Clean. Prod. 2018;212:622–629. doi: 10.1016/j.jclepro.2018.12.069. DOI

Diekow J., Mielniczuk J., Knicker H., Bayer C., Dick D.P., Kogel-Knabner I. Soil C and N stocks as affected by cropping systems and nitrogen fertilisation in a southern Brazil Acrisol managed under no-tillage for 17 years. Soil Tillage Res. 2005;81:87–95. doi: 10.1016/j.still.2004.05.003. DOI

Trapet P., Avoscan L., Klinguer A., Pateyron S., Citerne S., Chervin C. The Pseudomonas fluorescens siderophore pyoverdine weakens arabidopsis thaliana defense in favor of growth in iron-deficient conditions. Plant Physiol. 2016;171:675–693. doi: 10.1104/pp.15.01537. PubMed DOI PMC

Dragicevic V., Oljaca S., Stojiljkovic M., Simic M., Dolijanovic Z., Kravic N. Effect of the maize-soybean intercropping system on the potential bioavailability of magnesium, iron and zinc. Crop Pasture Sci. 2015;66:1118–1127. doi: 10.1071/CP14211. DOI

Vanisha K., Atwal A.K., Dhaliwal S.S., Banga S.K. Assessment of diverse sesame (Sesamum indicum L) germplasm for mineral composition. J. Plant Sci. Res. 2013;2:61–68.

Graham R.D., Welch R.M., Bouis H.E. Addressing micronutrient malnutrition through enhancing the nutritional quality of staple foods: Principles, perspectives and knowledge gaps. Adv. Agron. 2001;70:77–142.

Jhanji S., Sadana U.S., Sekhon N.K., Khurana M.P.S., Sharma A., Shukla A.K. Screening diverse wheat genotypes for manganese efficiency based on high yield and uptake efficiency. Field Crops Res. 2013;154:127–132. doi: 10.1016/j.fcr.2013.07.015. DOI

Jegadeeswari D., Chitdeshwari T., Boominathan P. Screening of short duration rice genotypes for zinc efficiency. J. Exp. Biol. Agric. Sci. 2019;7:25–33.

Disseminating Orange-Fleshed Sweet Potato Uganda Country Report. Harvestplus; Washington, DC, USA: 2012.

Menkir A., Palacios-Rojas N., Alamu O., Dias Paes M.C., Dhliwayo T., Maziya-Dixon B., Mengesha W., Ndhlela T., Oliveira Guimaraes P.E., Pixley K., et al., editors. Vitamin A-Biofortified Maize: Exploiting Native Genetic Variation for Nutrient Enrichment. CIMMYT, IITA, EMBRAPA, HarvestPlus, and Crop Trust; Bonn, Germany: 2018. (Science Brief: Biofortification Series, No. 2).

Hindu V., Palacios-Rojas N., Babu R., Suwarno W.B., Rashid Z., Usha R., Saykhedkar G.R., Nair S.K. Identification and validation of genomic regions influencing kernel zinc and iron in maize. Theor. Appl. Genet. 2018;131:1443–1457. doi: 10.1007/s00122-018-3089-3. PubMed DOI PMC

Trijatmiko K.R., Dueñas C., Tsakirpaloglou N., Torrizo L., Arines F., Adeva C., Balindong J., Oliva N. Biofortified indica rice attains iron and zinc nutrition dietary targets in the field. Sci. Rep. 2016;6:19792. doi: 10.1038/srep19792. PubMed DOI PMC

Boonyaves K., Wu T.Y., Gruissem W., Bhullar N.K. Enhanced grain iron levels in rice expressing an iron-regulated metal transporter, nicotianamine synthase, and ferritin gene cassette. Front. Plant Sci. 2017;8:130. doi: 10.3389/fpls.2017.00130. PubMed DOI PMC

Banakar R., Alvarez-Fernandez A., Diaz-Benito P., Abadia J., Capell T., Christou P. Phytosiderophores determine thresholds for iron and zinc accumulation in biofortified rice endosperm while inhibiting the accumulation of cadmium. J. Exp. Bot. 2017;68:4983–4995. doi: 10.1093/jxb/erx304. PubMed DOI PMC

Gupta A., Eral B., Hatton T.A., Doyle P.S. Nanoemulsions: Formation, properties and applications. Soft Matter. 2016;12:2826–2841. doi: 10.1039/C5SM02958A. PubMed DOI

Montoya M., Guardia G., Recio J., Castellano-Hinojosa A., Ginés C., Bedmar E.J., Álvarez J.M. Vallejo, A. Zinc-nitrogen co-fertilization influences N2O emissions and microbial communities in an irrigated maize field. Geoderma. 2021;383:114735. doi: 10.1016/j.geoderma.2020.114735. DOI

Schiavon M., Nardi S., dalla Vecchia F. Selenium biofortification in the 21st century: Status and challenges for healthy human nutrition. Plant Soil. 2020;453:245–270. doi: 10.1007/s11104-020-04635-9. PubMed DOI PMC

Ramkissoona C., Degryse F., Young S., Bailey E.H., McLaughlin M.J. Effect of soil properties on time-dependent fixation (ageing) of selenite. Geoderma. 2021;383:114741. doi: 10.1016/j.geoderma.2020.114741. DOI

Gonzali S., Kiferle C., Perata P. Iodine biofortification of crops: Agronomic biofortification, metabolic engineering and iodine bioavailability. Curr. Opin. Biotechnol. 2017;44:16–26. doi: 10.1016/j.copbio.2016.10.004. PubMed DOI

Singh B.R., Timsina Y.N., Lind O.C., Cagno S., Janssens K. Zinc and iron concentration as affected by nitrogen fertilization and their localization in wheat grain. Front. Plant Sci. 2018;9:307. doi: 10.3389/fpls.2018.00307. PubMed DOI PMC

Aziz M.Z., Yaseen M., Abbas T., Naveed M., Mustafa A., Hamid Y., Saeed Q., Xu M.G. Foliar application of micronutrients enhances crop stand, yield and the biofortification essential for human health of different wheat cultivars. J. Integr. Agric. 2019;18:1369–1378. doi: 10.1016/S2095-3119(18)62095-7. DOI

Zou C., Du Y., Rashid A., Ram H., Savasli E., Pieterse P., Cakmak I. Simultaneous biofortification of wheat with zinc, iodine, selenium and iron through foliar treatment of a micronutrient cocktail in six countries. J. Agric. Food Chem. 2019;67:8096–8106. doi: 10.1021/acs.jafc.9b01829. PubMed DOI

Wu C., Dun Y., Zhang Z., Li M., Wu G. Foliar application of selenium and zinc to alleviate wheat (Triticum aestivum L.) cadmium toxicity and uptake from cadmium-contaminated soil. Ecotoxicol. Environ. Saf. 2020;190:110091. doi: 10.1016/j.ecoenv.2019.110091. PubMed DOI

Jalal A., Shah S., Carvalho Minhoto Teixeira F. Agro-biofortification of zinc and iron in wheat grains. Gesunde Pflanz. 2020;72:227–236. doi: 10.1007/s10343-020-00505-7. DOI

Chen Y., Jia Z., Liu K., Tian X., Wang S., Wang S., Li X., Zhao H., Shar A.G. Response of exogenous zinc availability and transformation to maize straw as affected by soil organic matter. Soil Fertil. Plant Nutr. 2017;81:814–827. doi: 10.2136/sssaj2016.11.0374. DOI

Verma V., Kaur M., Greneche J.M. Tailored structural, optical and magnetic properties of ternary nanohybrid Mn0.4Co0.6−xCuxFe2O4 (x = 0, 0.2, 0.4, 0.6) spinel ferrites. Ceram. Int. 2019;45:10865–10875. doi: 10.1016/j.ceramint.2019.02.164. DOI

Du W., Yang J., Peng Q., Liang X., Mao H. Comparison study of zinc nanoparticles and zinc sulphate on wheat growth: From toxicity and zinc biofortification. Chemosphere. 2019;227:109–116. doi: 10.1016/j.chemosphere.2019.03.168. PubMed DOI

Hussain B., Li J., Ma Y., Tahir N., Ullah A. Effects of Fe and Mn cations on Cd uptake by rice plant in hydroponic culture experiment. PLoS ONE. 2020;15:e0243174. doi: 10.1371/journal.pone.0243174. PubMed DOI PMC

Kabiri S., Degryse F., Tran D.N.H., da Silva R.C., McLaughlin M.J., Losic D. Graphene Oxide: A New Carrier for Slow Release of Plant Micronutrients. ACS Appl Mater. Interfaces. 2017;9:43325–43335. doi: 10.1021/acsami.7b07890. PubMed DOI

Ivanov K., Tonev T., Nguyen N., Peltekov A., Mitkov A. Impact of foliar fertilization with nanosized zinc hydroxy nitrate on maize yield and quality. Emir. J. Food Agric. 2019;31:597–604. doi: 10.9755/ejfa.2019.v31.i8.2003. DOI

Chhipa H. Nanofertilizers and nanopesticides for agriculture. Environ. Chem. Lett. 2017;15:15–22. doi: 10.1007/s10311-016-0600-4. DOI

An X., Wu Z., Yu J., Ge L., Li T., Liu X., Yu B. High-efficiency reclaiming phosphate from an aqueous solution by bentonite modified biochars: A slow release fertilizer with a precise rate regulation. ACS Sustain. Chem. Eng. 2020;8:6090–6099. doi: 10.1021/acssuschemeng.0c01112. DOI

Yoon H.Y., Lee J.G., Esposti L.D., Iafisco M., Kim P.J., Shin S.G., Adamiano A. Synergistic release of crop nutrients and stimulants from hydroxyapatite nanoparticles functionalized with humic substances: Toward a multifunctional nanofertilizer. ACS Omega. 2020;5:6598–6610. doi: 10.1021/acsomega.9b04354. PubMed DOI PMC

Yugandhar P., Savithramma N. Green synthesis of calcium carbonate nanoparticles and their effects on seed germination and seedling growth of Vigna mungo (L.) Hepper. Int. J. Adv. Res. 2013;1:89–103.

Ramírez-Rodríguez G.B., Dal Sasso G., Carmona F.J., Miguel-Rojas C., Pérez de Luque A., Masciocchi N., Delgado-López J.M. Engineering biomimetic calcium phosphate nanoparticles: A green synthesis of slow-release multinutrient (NPK) nano-fertilizers. ACS Appl. Bio Mater. 2020;3:1344–1353. doi: 10.1021/acsabm.9b00937. PubMed DOI

Singh D., Rajawat M.V.S., Kaushik R. Beneficial role of endophytes in biofortification of Zn in wheat genotypes varying in nutrient use efficiency grown in soils sufficient and deficient in Zn. Plant Soil. 2017;416:107–116. doi: 10.1007/s11104-017-3189-x. DOI

Watts-Williams S.J., Cavagnaro T.R. Arbuscular mycorrhizal fungi increase grain zinc concentration and modify the expression of root ZIP transporter genes in a modern barley (Hordeum vulgare) cultivar. Plant Sci. 2018;274:163–170. doi: 10.1016/j.plantsci.2018.05.015. PubMed DOI

Yadav R., Ror P., Rathore P., Ramakrishna W. Bacteria from native soil in combination with arbuscular mycorrhizal fungi augment wheat yield and biofortification. Plant Physiol. Biochem. 2020;150:222–233. doi: 10.1016/j.plaphy.2020.02.039. PubMed DOI

Stepien A., Wojtkowiak K. Effect of foliar application of Cu, Zn, and Mn on yield and quality indicators of winter wheat grain. Chil. J. Agric. Res. 2016;76:219–226. doi: 10.4067/S0718-58392016000200012. DOI

Nawaz F., Ahmad R., Ashraf M.Y. Effect of selenium foliar spray on physiological and biochemical processes and chemical constituents of wheat under drought stress. Ecotoxicol. Environ. Saf. 2015;113:191–200. doi: 10.1016/j.ecoenv.2014.12.003. PubMed DOI

Aciksoz S.B., Ozturk L., Yazici A., Cakmak I. Inclusion of urea in a 59Fe EDTA solution stimulated leaf penetration and translocation of 59Fe within wheat plants. Physiol. Plant. 2014;151:348–357. doi: 10.1111/ppl.12198. PubMed DOI

Blasco B., Ríos J.J., Sánchez-Rodríguez E. Study of the interactions between iodine and mineral nutrients in lettuce plants. J. Plant Nutr. 2012;35:1958–1969. doi: 10.1080/01904167.2012.716889. DOI

Wang S., Li M., Liu K. Effects of Zn, macronutrients, and their interactions through foliar applications on winter wheat grain nutritional quality. PLoS ONE. 2017;12:e0181276. doi: 10.1371/journal.pone.0181276. PubMed DOI PMC

Aciksoz S.B., Yazici A., Ozturk L., Cakmak I. Biofortification of wheat with iron through soil and foliar application of nitrogen and iron fertilizers. Plant Soil. 2011;349:215–225. doi: 10.1007/s11104-011-0863-2. DOI

Naeem A., Aslam M., Lodhi A. Improved potassium nutrition retrieves phosphorus-induced decrease in zinc uptake and grain zinc concentration of wheat. J. Sci. Food Agric. 2018;98:4351–4356. doi: 10.1002/jsfa.8961. PubMed DOI

Hussain B., Lin Q., Hamid Y., Sanaullah M., Di L., Hashmi M.L., Yang X. Foliage application of selenium and silicon nanoparticles alleviates Cd and Pb toxicity in rice (Oryza sativa L.) Sci. Total Environ. 2020;712:136497. doi: 10.1016/j.scitotenv.2020.136497. PubMed DOI

Wang S., Li M., Tian X. Foliar zinc, nitrogen, and phosphorus application effects on micronutrient concentrations in winter wheat. Agron. J. 2015;107:61–70. doi: 10.2134/agronj14.0414. DOI

Hussain A., Ali S., Rizwan M., Rehman M.Z., Qayyum M.F., Wang H., Rinklebe J. Responses of wheat (Triticum aestivum) plants grown in a Cd contaminated soil to the application of iron oxide nanoparticles. Ecotoxicol. Environ. Saf. 2019;173:156–164. doi: 10.1016/j.ecoenv.2019.01.118. PubMed DOI

Sarwar N., Akhtar M., Kamran M.A., Imran M., Riaz M.A., Kamran K., Hussain S. Selenium biofortification in food crops: Key mechanisms and future perspectives. J. Food Compos. Anal. 2020;93:103615. doi: 10.1016/j.jfca.2020.103615. DOI

Yang L., Fan I., Huang B., Xin J. Efficiency and mechanisms of fermented horse manure, vermicompost, bamboo biochar, and fly ash on Cd accumulation in rice. Environ. Sci. Pollut. Res. 2020;27:27859–27869. doi: 10.1007/s11356-020-09150-z. PubMed DOI

Maqsood M.A., Schoenau J., Vandenberg A. Zinc fertilization of lentil for grain yield and grain zinc concentration in ten Saskatchewan soils. J. Plant Nutr. 2015;39:866–874. doi: 10.1080/01904167.2015.1090606. DOI

Yaseen M.K., Hussain S. Zinc-biofortified wheat required only a medium rate of soil zinc application to attain the targets of zinc biofortification. Arch. Agron. Soil Sci. 2020;67:551–562. doi: 10.1080/03650340.2020.1739659. DOI

Haider M.U., Hussain M., Farooq M., Nawaz A. Soil application of zinc improves the growth, yield and grain zinc biofortification of mungbean. Soil Environ. 2018;37:123–128.

Ozbahce A., Zengin M. Effects of foliar and soil applications of different manganese fertilizers on yield and net return of bean. J. Plant Nutr. 2014;37:161–171. doi: 10.1080/01904167.2013.859701. DOI

Ramzan Y., Hafeez M.B., Khan S., Nadeem M., Batool S., Ahmad J. Biofortification with zinc and iron improves the grain quality and yield of wheat crop. Int J. Plant Prod. 2020;14:501–510. doi: 10.1007/s42106-020-00100-w. DOI

Golden B.R., Orlowski J.M., Bond J.A. Corn injury from foliar zinc application does not affect grain yield. Agron. J. 2016;108:2071–2075. doi: 10.2134/agronj2015.0593. DOI

Selenium Status of Southern Africa