Table 1.

Summary of the studies conducted using different forms nanomaterials for wheat nano-biofortification and the obtained impact in terms of nutrient content in seed grain in comparison to the control (no nanomaterial applied) and conventional agronomic biofortification applications (wherever present). (NC = No comparison was done with conventional fertilizers in this study).

Reference	Type of Application	Place of Trial	Growth Medium	On Application of Nanomaterial				On Application of Conventional Fertilizers
				Applied Nanomaterial	Amount Applied	Nutrient Content in Grain without Application of Nanomaterial	Nutrient Content in Grain on Addition of Nanomaterial	Applied Conventional Fertilizer	Amount Applied	Nutrient Content in Grain on Addition of Conventional Fertilizers
Deshpande et al. 2017	Foliar	PVC columns	Sand	Zn-CNP	≈20 mg g−1, ≈25mL	≈15–19 µg g−1 DW Zn	≈21–25 µg g−1 DW Zn	NC
Xue et al. 2017	Soil	Pot	Soil	Nanochitin	0.006 g kg−1	184.3 g kg−1 protein 58.6 mg kg−1 Fe 42.13 mg kg−1 Zn	204.1 g kg−1 protein 65.39 mg kg−1 Fe 51.45 mg kg−1 Zn	NC
Zhang et al. 2017	Foliar	Field	Soil	ZnO NP	2 g L−1 at a rate of 1.2 kg ha−1	18.4 mg kg−1 (Year 1) Zn 23.6 mg kg−1 (Year 2) Zn	26.5 mg kg−1 (Year 1) Zn 34.6 mg kg−1 (Year 2) Zn	ZnSO4	7 g L−1 at a rate of 4.2 kg ha−1	21.1 mg/kg (Year 1) Zn 29.5 mg kg−1 (Year 2) Zn
Dapkekar et al. 2018	Foliar	Field	Soil	Zn-CNP	40 mg L−1	39.5 µg g−1	53.3 µg g−1	ZnSO4	400 mg L−1	59.40 µg g−1 Zn
Munir et al. 2018	Seed Priming	Pot	Soil	ZnO NPs	100 mg L−1	≈12 mg kg−1 DW Zn	≈20 mg kg−1 DW Zn	NC
Burhan and Al-Hassan et al. 2019	Foliar	Field	Soil	Nano NPK	750:90:600 mg L−1	-	13.5 % protein	traditional NPK	400 kg ha−1 urea, 200 kg ha−1 tri super phosphate, 100 kg ha−1 K2SO4	10.68 % protein
Hussain et al. 2019	Foliar	Pot	Soil	Fe3O4 NP	20 mg kg−1	≈40 mg kg−1 DW Fe	≈120 mg kg−1 DW Fe	NC
Hussain et al. 2019	Soil	Pot	Soil	Fe3O4 NP	20 mg kg−1	≈40 mg kg−1 DW Fe	≈90 mg kg−1 DW Fe	NC
Khan et al. 2019	Soil	Field	Soil	ZnO NP	100 mg kg−1	≈20 mg kg−1 DW Zn	≈45 mg kg−1 DW Zn	NC
Rizwan et al. 2019	Seed Priming	Pot	Soil	ZnO NPs	100 mg L−1	≈15 mg kg−1 DW Zn	≈30 mg kg−1 DW Zn	NC
Rizwan et al. 2019	Seed Priming	Pot	Soil	Fe NPs	20 mg L−1	≈15 mg kg−1 DW Fe	≈30 mg kg−1 DW Fe	NC
Sundaria et al. 2019	Seed Priming	Pot Greenhouse	Soil	Fe2O3 NP	600 ppm	≈30–40 mg kg−1 DW Fe	≈40–45 mg kg−1 DW Fe	NC
Adrees et al. 2020	Soil	Pot	Soil	Fe2O3 NP	100 mg kg−1	≈20 mg kg−1 DW Fe	≈45 mg kg−1 DW Fe	NC
Adrees et al. 2021	Foliar	Pot	Soil	ZnO NP	100 mg L−1	≈22 mg kg−1 DW Zn	≈45 mg kg−1 DW Zn	NC
Astaneh et al. 2021	Soil	Field	Soil	Nano-chelated nitrogen	240 kg ha−1	-	69% protein 80 mg P 38 mg K	Urea	240 kg ha−1	17% protein 54 mg P 27 mg K
Hussain et al. 2021	Foliar	Field	Soil	Fe3O4 NP	5 mg L−1	≈30 mg kg−1 DW Fe	≈45 mg kg−1 DW Fe	NC
Hussain et al. 2021	Foliar	Field	Soil	ZnO NP	25 mg L−1	≈18 mg kg−1 DW Zn	≈25 mg kg−1 DW Zn	NC
Sheoran et al. 2021	Foliar	Pot	Soil	ZnO NP	120 ppm	17.48 mg g−1 FW Protein	22.71 mg g−1 FW Protein	Chemical Zn	-	19.91 mg g−1 FW Protein