Our randomised crossover trial of biofortified zinc flour in Peshawar (details in previous blog) is now well underway and our colleagues are busy with successive phases of flour distribution, data collection and lab work to process and store the biological samples.
Meanwhile, our partners at Fauji Fertilizer Company have just finished coordinating the sowing of a wheat crop at three experimental sites across Pakistan. The aim of this part of the BiZiFED project is to determine the value of adding zinc fertilizers to wheat production in Pakistan, both in terms of yield and the potential health benefits from increasing the zinc concentration in the grain of the wheat used to make roti or chapatti.
This component of our work is extremely important because the plant-available zinc concentration of most soils in Pakistan is very low compared to other parts of the world. This limits the zinc wheat crop, both in terms of yield and zinc concentration.
At each of the three experimental sites, replicated plots have been sown of the high-zinc wheat variety released by HarvestPlus (Zincol-2016) and a local references variety of wheat.
Research funded by the HarvestZinc Fertilizer Project and led by Professor Ismail Cakmak from Sabanci University in Turkey found that addition of zinc fertilizers to soil and foliage, known as agronomic biofortification, can increase yield and enhance zinc concentration in the edible part of the wheat grain. Foliar application of fertilizers late in the growing season has been shown to be the most consistent and effective strategy in many countries. Zinc concentration of wheat grain can be doubled compared to no fertilizer using this technique, especially when the crop receives adequate nitrogen.
While these field trials have shown huge promise, it is also important to demonstrate the cost-effectiveness of genetic (breeding) and agronomic (fertilizer) biofortification. This information will be essential to demonstrate to farmers the value in investing in new seeds and zinc fertilizers, and to persuade governments (in Pakistan and elsewhere) to invest in scaling-up biofortified zinc wheat and supporting the development of new fertilizer markets (e.g. quality control systems).
A recent study co-authored by several members of the BiZiFED team estimated the value of zinc fertilizer use on crop yield and dietary zinc intake in Pakistan. Our findings, based on farmer surveys but with several uncertainties in terms of future scenarios, indicated that application of zinc fertilizers to local wheat varieties could reduce the prevalence of zinc deficiency by 50% assuming no other changes to food consumption. The monetary value of increased yield was estimated at over US $800 million per year. The potential for combining new high-zinc varieties of wheat alongside zinc fertilizers were not considered in this study, however, we anticipate that the benefits of genetic and agronomic biofortification are likely to be additive, and maybe even synergistic.
Thanks to our expertise, spanning academic and private-sector partners, our BiZiFED project will generate new science-based evidence in a ‘real-world’ context, so that the cost-effectiveness of zinc fertilizers applied to the biofortified zinc wheat can be determined. We will calculate the health economic impact of new varieties and zinc fertilizer-use in terms of reductions in Disability Adjusted Life Years (DALYs). A DALY is a measure of overall disease burden, expressed as the number of years lost due to ill-health, disability or early death.
Ultimately, this study will show how many years of healthy life could be saved if the population was to fully adopt biofortified zinc wheat and zinc fertilizers.