Very strongly I feel so..it is one of the most potent strategies to achieve desired goals of biofortification..

Yes dear sure, their is no alternative ways than that of Agronomic Management Practices specially when micronutrients also applied the efficiency increased many times.....

Ability to adjust the base soil pH and strategically apply zinc are good avenues of addressing zinc deficiency constituting an excellent strategy of Zn biofortication. When soil pH is 7.3 or less zinc defiency is usually not an issue nor deficiency with iron or manganese. If foliage is showing symptoms the foliar application of 5 kg + 1 kg or urea and zinc sulfate is very effectiveIf foliar ppm When Zn is less than 25 ppm in the foliage significant positive response from fortification would be recommended . Potato can be very responsive to organic matter and the use organic amendment would be useful in an integrated plan. Potato is a very important crop nutrition with a high value but it does very high nutrition levels and is known as having high potassium and phosphorus demands as well as nitrogen requirments. For getting excellent potato crops P1 should exceed 30 K should exceed 200 and the availability of N should be similar to potassium. GMO potato to my understanding would be a regulatory issue. Traditionally breeding could be effective also. 

Agronomic biofortification of cereals with zinc: a review by I.  Cakmak and  

U. B. Kutman, DOI: 10.1111/ejss.12437  

Summary

Zinc (Zn) still represents an important health problem in developing countries, caused mainly by inadequate dietary intake. A large consumption of cereal-based foods with small concentrations and low bioavailability of Zn is the major reason behind this problem. Modern cultivars of cereals have inherently very small concentrations of Zn and cannot meet the human need for Zn. Today, up to 50% of wheat-cultivated soil globally is considered poor in bioavailable Zn. Agricultural strategies that are used to improve the nutritional value of crop plants are known as biofortification strategies. They include genetic biofortification, which is based on classical plant breeding and genetic engineering for larger nutrient concentrations, and greater agronomic biofortification, which is based on optimized fertilizer applications. This review focuses on agronomic biofortification with Zn, which has proved to be very effective for wheat and also other cereal crops including rice. Molecular and genetic research into Zn uptake, transport and grain deposition in cereals are critically important for identifying ‘bottlenecks’ in the biofortification of food crops with Zn. Transgenic plants with large Zn concentrations in seeds are often tested under controlled laboratory or glasshouse conditions with sufficient available Zn in the growth medium for the entire growth period. However, they might not always show the same performance under ‘real-world’ conditions with limited chemical availability of Zn and various stress factors such as drought. What purpose can an upgraded transport and storage system serve if the amount of goods to be transported and stored is limited anyway? Given the fact that the Zn concentrations required to achieve a measurable impact on human health are well above those required to avoid any loss of yield from Zn deficiency, providing crop plants with sufficient Zn through the soil and foliar fertilizer strategy under field conditions is critically important for biofortification efforts.

Highlights

Zinc malnutrition is a major global health issue associated with cereal-based diets.

Agronomic biofortification with Zn aims to provide edible parts of crop plants with sufficient Zn.

Biofortification with Zn fertilizers, particularly foliar applications, works well for wheat and other cereals.

Agronomic biofortification with Zn provides a practical and cost-effective option to tackle the global Zn malnutrition problem.

To date, four biofortified wheat varieties have been released – ‘Zincol 2016’ in Pakistan, ‘Zinc Shakti (Chitra)’, ‘WB02’ and ‘HPBW-01’ in India (Box 2). The now proven high bioavailability (% absorption) of Zn from wheat in human diets translates to significant nutritional impact. Nutrition trials with high Zn wheat have shown (i) an increase in Zn intake [8] and (ii) a reduction in child morbidity.

 ‘Zinc Shakti (Chitra)’, ‘WB02’ and ‘HPBW-01’ have  same potential of yield like others variety or not. 

 Biofortification with Zn application in soil provides a practical and cost-effective solution to Zn malnutrition. Basic studies are still lacking and most of the studies relate to cereals but what about fruit crops which are important from nutritional security point of view. Do we have agronomic biofortification with Zn studies for perenials. 

Yes, agronomic practices can enhance Zn loading in grains. There are some varieties of cereals (wheat and rice in Bangladesh) that can uptake more Zn from soil than other varieties.

Compared to plant residues animal manures are rich in micronutrients as well as humic materials. These contents and their value is increase with composting. Compared to cereal grains, legumes are much higher in micronutrient. In the legume crop the micronutrient can be supplied economically by farmer applied seed treatment. For the increase in the animal and farm nutrition it is important to re discover the role and importances of legumes in rotation with grains and the return of residues and manures ares value added compost. In terms of nutrition the majority of grain poor zinc is related to over refining of cereal products. For optimized human nutrition at least 25% of the staple ration would need to be grain legume. Narrow focus on the just the cereal grains and not on the production systems is part of the problem and not the solution. This type of issue needes a holistic approach rather than commodity approach. 

The uptake efficiency of zinc and other micro nutrients depends upon the genetic constitution of plants. Some varieties are more efficient to uptake these nutrients from the soil. The  latest example is the development of WB-02 ( First biofortified variety of Wheat). This variety has been developed through conventional breeding approach.

Somewhere , we have drifted the entire discussion  on such an interesting issue , including me ...Let us concentrate on the practices that can lead to greater accumulation of Zn , atleast in edible plant parts , to say the least . Foliar nutrition is one such option , but again , there are many issues associated with effectiveness of foliar nutrition , mor e so in annual filed crops than perennial fruit crops.. waiting for wonderful ideas of Paul Hepperly...Dr Malhotra  is raising a very pertinent point..

From the initiation of manufacture through light or photosynethesis, Carbon is married to water. Indeed all plant nutriition is mobilized through water to be absorbed into the crop plant. Naturallly high soil organic matter serves as a buffering mechanism in the sense that it prevents massive loss of both water and nutrients working as a closed loop system. I like to envision this as the Carbon battery. So as we look to the creative wisdom of the natural world the level of Carbon is a barometer of the state of the land resource. Much of the both the water availability and the nutrient availability is a function of organic matter status of the soil. For biofortification when the level of soil organic matter which has been largely depleted in our industrial farming system is raised the ability to absorb water, to provide water and nutrients increase. If we concentrate on the basics nutrition beside being concerned about the level of Carbon in the carbon battery we need to be aware with fundamental fact that pH governs so much of nutiritient availability and that soil organic matter biological activity is also very much a function of this critical state. The comprehensive approach agronomically is to understand that seed and foliar treatments are stop gap measures but our systematic plan needs to focus on the soil medium. Few farmers never the less know the pH of their soils and how it varies nor the level of the organic matter or have goals and plans to deal with these limitation. In a certified organic approach the farmer must develop a soil conservation plan and have a farming system which can improve and maintain the productivity of the land itself. Rather than take a narrow nutrient or crop focus we need to look to systematic approaches which have goals related to our core resources. Monocultural systems and approaches are not a part of solution because their lack of diversity is associated with system that are leaky losing over time the exact resources we need to promote core biological activity. In a Carbon depleted system the plants and animals with have multiple nutrient imbalances and the health of the system will suffer. In the closed loop system mimicing the tried and true principles of nature the system can be both improved and closed. The improved and closed system will improve productivity of our plants our animals and ourselves and will lead to greater health. Indeed many of all our issues are related to leakiness of our systems and waste of resources which are need in ground we stand upon. In our agricultural systems we need to go back to a soil based focus rather than think everything is resolved by band aids and stop gap measures. 

Yes indeed. Considering the soil conditions in Indian scenario with alkaline pH, calcareous nature of soil and low zinc content agronomic biofortification is most preferred and short term approach. However in agronomic biofortification too the foliar application is the most preferred mode. Because for zinc enhancement in grain the foliar application at flowering or anthesis stage results in maximum zinc mobilisation from source (leaves) to sink (seeds). Besides it takes advantage of senescence process and help in zinc accumulation in grains and hence biofortification.

Biofortiification protocol. 1) seed treatment 2) soil treatment 3) foliar treatment 4) monitoring by soil and plant tissue sampling. 5) policy to favor crop plants with adequate zinc levels and 6) emphasize whole grain productis which are much richer in micronutrients.