Organic manures: an efficient move towards maize grain biofortification

maize growth and Zn bioavailability in maize grain. Methods In a field experiment, maize (Zea mays) was supplemented with farm yard manure (FYM), press mud (PM), fisheries manure (FM), and slaughter house waste (SHW) in combination with Zn soil application (ZnS) and Zn foliar spray (ZnF) with recommended doses of N:P:K (140:100:60 kg ha−1), respectively. Besides assessing the maize growth, grain, and straw yield, Zn bioavailability in maize grain was also studied. Results Organic materials combined with ZnS and ZnF significantly increased the maize yield and Zn bioavailability. PM + ZnS increased the grain yield by 69.71%, while FM + ZnF and FYM + ZnF increased the grain Zn concentration by 86.37 and 86.16%, respectively. Moreover, grain Zn content was greatly influenced by PM + ZnS and PM + ZnF resulted an average increase by 160%. Phytate concentration and phytae:Zn molar ratio in grain were decreased by 30.34 and 66.92%, respectively by FYM + ZnF. Estimated Zn bioavailability ranged from 0.92 to 2.04 mg Zn/300 g in maize grain, and was maximum by PM and FYM combined with ZnF. Conclusion Organic manures influence the nutrient uptake from soil, increase the product quality, and act as a good organic fertilizer. The current study revealed that organic manures can enhance crop growth and Zn uptake in grain in sustainable manner. It would be an eco-friendly approach by utilizing organic wastes annually generated by agro industries.