Biofortification of Plants to Benefit People

Many of the elements considered essential to good diets of humans and animals also play important roles in plant metabolism. However, in Brazil as elsewhere, during the quest for higher yields to satisfy global consumption, attention has been less focused on plant nutrition for the nutritive value of the crop at harvest. The challenge to modern agriculture now is to target balanced nutrition for plants not just to achieve production goals, but also for the sake of better human, and animal, nutrition. 

The Challenge of Poor Soil Fertility

Tropical soils, usually have low natural fertility due to soil type and the high degree of weathering that occurs in these regions. Problems include low pH values, deficiencies of nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, boron, and zinc which all limit productivity in these areas. Any nutritional deficiency can cause long-lasting and yield-reducing damage. On the other hand, well-nourished plants can better withstand adversities, whether biotic or abiotic. Soil fertility management that increases the diversity, quantity, and availability of essential and beneficial elements in the soil, and consequently the productivity of agricultural crops, is urgently needed. Focus is shifting to the potential of often over-looked elements. 

Linking Plant Nutrition with Human Nutrition

It is estimated that over three billion people worldwide suffer from food insecurity and have deficiencies in their diet of essential elements including in iron, zinc, selenium, and vitamin A. Human health is negatively impacted. These same elements are important for plant health. Recent studies of maize plants that had been subjected to water stress show that foliar application of selenium increased water use efficiency, and increased chlorophyll and carotenoid contents. In addition, responses in antioxidant metabolism, growth and productivity gains were observed when selenium was applied during the flowering in wheat, coffee, and bean plants. Furthermore, tomato crops that received applications of selenium had their biological age reduced and the storage time of the fruits was increased. Although there have been improvements in soil management, it is estimated that 50% of soils that grow grains are deficient in zinc. According to recent research, 58% of land in Brazil is at risk of zinc deficiency for crops. Zinc is essential for carrying out several metabolic processes in the plant, including photosynthesis, protein synthesis, maintenance of membrane integrity, auxin metabolism, and reproduction. Therefore, maintaining adequate zinc levels is essential for the process of stress tolerance and recovery. Magnesium is a central molecule of chlorophyll, increasing CO₂ fixation and assisting in the thermal dissipation so that cell damage does not occur. Recent studies have shown that if plants under stress are given a foliar application of magnesium chlorophyll synthesis, carbon assimilation, and water use efficiency increased consequently improving productivity in most crops. 

Biofortification of Crops for Better Nutrition of People

Biofortification is the process of increasing the nutritional value of a crop to enrich the final product with certain elements. Biofortified crops contain better agronomic and nutritional characteristics than those that have not undergone this process. Biofortification can be through the results of a genetic approach, whether that is conventional plant breeding or transgenic, industrial fortification, or through an agronomic approach. With the development of NutriDuo, ICL has addressed the problem of inadequate supplies to plants of the elements that have stress-relieving effects, particularly selenium, zinc, and magnesium. 

Introducing NutriDuo: Balanced, Powerful and Simple to Use

Firstly, NutriDuo contains the right balance of nutrients to deliver the best results for a diverse range of crops. It contains an innovative source of magnesium that makes it more efficient at delivering this nutrient when compared to other sources used in agriculture until now. This new source, which was developed by the Research and Development of ICL, consists of a magnesium form or chelate with high stability right across the pH spectrum, from 1.5 to 13. Secondly, NutriDuo acts on plants in several important ways:

• Photoprotection – the presence of selenium increases the production of carotenoids, improving the energy dissipation from the plant’s photosynthetic apparatus before it can cause damage to the plants
• Activation of the plant’s antioxidant system – the application of micronutrients and selenium, in low concentrations, has a direct beneficial effect on enzymes that fight oxidative stress in plants which can be caused by challenging environmental conditions
• Transport of energy-storing compounds or photoassimilates from the leaves – elements such as magnesium and selenium improve the flow of photoassimilates in the circulatory system, or phloem vessels, around the plant

Thirdly, NutriDuo has very high solubility (1,000 g/L water), making application solutions quick to prepare and use. Plus, it has high compatibility with pesticides and amino acids. In other words, with these technical benefits, there are no problems with clogged nozzles or filters, and there will be no residue at the bottom of the sprayer tank after application. 

Facts from the Field

For soybean in Brazil, the best application time for NutriDuo was found to be at stage R3, the start of pod formation, and at a rate of 1 kg/ha. It was found that after the application of NutriDuo there was an increase in the levels of selenium in the grains (Figure 1) and an increase in productivity (Table 1). 

 

Consistent increase in soybean productivity with NutriDuo from 11 demonstration fields

City	Standard productivity	Nutriduo productivity	Increase in productivity
	sacks/ha	sacks/ha	sacks/ha
Maracaju - MS	66.23	69.3	3.07
Tibagi - PR	63.33	64.33	1.00
Moreira Sales - PR	53.3	54.13	0.83
Cruz Alta - RS	62.47	64.50	2.03
Campo Novo do Parecis - MT	49.28	55.46	6.18
Castro - PR	77.43	78.86	1.43
Santa Bárbara - RS	97.40	100.32	2.92
Erechim - RS	74.00	78.00	4.00
Catuípe - RS	68.90	71.26	2.36
Capão Bonito - SP	90.50	92.30	1.80
lracemápolis - SP	104.80	106.30	1.50

  Within the plants, the benefits of applied NutriDuo were also evident. High proline levels are a sign of plant stress, but the soybean plants which received NutriDuo had significantly lower proline levels (Figure 2). 

  It is estimated that many crops achieve as little as 24% of their productive potential, and that 11% is lost as a result of biotic stress. The remaining 65% can be lost to abiotic stresses such as inadequate nutrition from soil and fertilization strategies. The growth of more detailed understanding of these inadequacies and the development of biofortification and fertilizer technologies such as NutriDuo are major steps to optimizing nutrition of plants, and subsequently, the people that need to be adequately nourished by them.