**6. Agronomic approaches for biofortification**

The most significant contribution to human health and prevention is probably an adequate and balanced diet that provides the energy routes, vital amino acids (lysine, methionine), vitamins (A, B, C, D and E), minerals, folic acids, and ionic elements (Fe, Zn, I, and Se). Targeted administration of soluble inorganic fertilizers to the roots or to the leaves is used when crops are produced in soils where mineral elements become instantly unavailable in the soil and/or not rapidly translocated to edible tissues. Agronomic biofortification is easy and cheap, but it requires specific consideration when it comes to nutrient supply, application technique, and environmental impact as discussed in **Table 6**. Hence, in certain situations, are less cost-effective. The success of Se fertilization of crops in Finland [84], zinc fertilization in Turkey [85], and I fertilization in irrigation water in China serve as examples of how mineral fertilizers might be used in developed countries [86]. In addition to fertilizers, nutrient mobility from the soil to the edible sections of plants can be improved by using


#### **Table 6.**

*Contribution of agronomic bio-fortification in increasing the grain Zn and Fe concentrations and uptake in different crops [74].*

#### *Agronomic Biofortification of Millets: New Way to Alleviate Malnutrition DOI: http://dx.doi.org/10.5772/intechopen.110805*

soil microbes that promote plant development. To boost the Phyto availability of mineral elements, soil microbes from the genera Bacillus, Pseudomonas, Rhizobium, and others can be used [87, 88]. When nitrogen is scarce, the N2-fixing bacteria are crucial for enhancing crop output [89]. Numerous crops have mycorrhizal fungus attached to them, which can emit organic acids, siderophores, and enzymes that can break down organic molecules and raise the mineral content of edible product [87, 90].

A good technique for supplementing micronutrient powders and promoting dietary diversity is agronomic biofortification, which is the process of increasing the density of nutrients, vitamins, and minerals in a crop by using suitable agronomic practices.

The following are the main benefits of agronomic biofortification:


#### **6.1 Agronomic biofortification in sorghum**

Sorghum crop often suffers from the challenge of growing in nutrient poor and contaminated soil. The nutrient profile has been promoted by the application of fertilizers (both organic and inorganic) that have an additive effect on the yield. Researchers have intended to improve the nutrient uptake and alter the metabolic profile of sorghum by using the combination of plant growth-promoting bacteria and arbuscular mycorrhizal fungi (AMF) [81, 82]. Also, the inoculation of *Azospirillum* alone and in combination with phosphate-solubilizing bacteria increased sorghum grain yield and protein content by improving the status of phosphorous and nitrogen in the soil [83].

#### **6.2 Agronomy biofortification through fertilization techniques**

We are unaware of other studies that similarly quantified the direct impact of agronomic biofortification on dietary intake of micronutrients on human health. Even though it is shown that agronomic biofortification has the potential to increase micronutrient contents in crops, literature connecting these enhanced concentrations to micronutrient bioavailability, dietary intake and human health are scarce [91]. Such studies do exist on genetically biofortified crops, such as in the case of Indian schoolchildren consuming iron biofortified pearl millet [92]. Modeled estimations have been made on the potential of agronomic biofortification using agronomic and dietary data [93] proposed that future study on micronutrient bioavailability, including metabolic pathways that impact absorption and the health benefits of various chemical forms of micronutrients, is necessary to further establish the legitimacy of

agronomic biofortification. The rate of adoption at the stakeholder level is quicker because fertilization is associated with the economy in both the short- and long-term [94], which is evident in both the rate of micronutrient application and the usage of micronutrient-fortified fertilizers [95]. To define the potential and essential circumstances for agronomic biofortification to improve human health, systematic study is needed.

### **6.3 Agronomic biofortification compared with other interventions**

When compared to other intervention strategies like genetic biofortification, food fortification, supplementation, and dietary diversification, the question of whether agronomic biofortification is an efficient, workable, and sustainable approach to addressing micronutrient deficiencies still needs to be answered. Rarely do economic evaluations take agronomic biofortification into account when comparing the relative effects of various initiatives on nutrition. In comparison to other treatments, genetic biofortification is more economical over time than food fortification, supplementation, or dietary diversification since it only needs one breeding investment period [96, 97]. In addition to genetic biofortification (breeding), which is viewed as a more permanent technique, agronomic biofortification is frequently perceived as a temporary option to boost micronutrient availability [98, 99]. Breeding, according to [100] is the only agricultural intervention that may increase the nutritional value of staple crops in low-income countries since farmers with limited resources do not have access to or can pay fertilizers. Dietary diversity, according to the CGIAR biofortification programme, is the best sustainable option, yet those who are most at risk frequently cannot afford various foods. According to [101] concentrated metropolitan regions are most suited for supplements and food diversification programmes, whereas rural people are best served through agronomic biofortification.
