A new vision for micronutrients For improving harvests, human health and the environment 1

Transcription

1 A new vision for micronutrients For improving harvests, human health and the environment 1 The challenge Demand for food is increasing rapidly, and it will continue to do so. The two main reasons for this increase are the world s growing population and a shift in diets that requires even more food production capacity. Feeding everybody sustainably remains a huge challenge. Sustainably in this context means healthy without harm to the environment. Meeting human food and nutritional needs within the ecological limits of our planet requires careful attention to production methods. In this brochure, we explain how fertilizers containing micronutrients 2 could contribute. Mineral fertilizers play a major role in modern agriculture. They increase crop yields and therefore help improve food security. The main chemical elements involved are the macronutrients nitrogen (N), phosphorus (P) and potassium (K). Nitrogen is drawn from the air, while the other two elements come from ores; all three are required in large quantities. Smaller amounts are needed of 11 micronutrients that are also essential for plant growth and health. In the past, however, fertilizer use has often only involved N, P and K. In an ideal system, farmers would use exactly the right amount and composition of fertilizer for crops to take up all the nutrients applied. Much progress has been made over the past decades, but still today s agriculture is far less efficient. A large percentage of the nutrients in fertilizers are harmfully wasted. Much of the nitrogen escapes as a greenhouse gas, which contributes to global warming. Both nitrogen and phosphorus can also leak out from the soil into groundwater, streams and lakes, causing eutrophication, and then it ultimately flows into the sea. The negative effects on the environment increase when farmers apply too much fertilizer. When they use too little, however, crops lack nutrients. Consequently, crop yields and farmers incomes fall, and improved food security becomes harder to achieve. Fertilizers not containing the right balance of nutrients also contribute to low uptake and high losses, and to low nutritional food quality hampering human health. Basic fertilizer production techniques are at least four to five decades old. Unfortunately, public and private research has not engaged in designing truly innovative fertilizer products, and no groundbreaking technologies have been launched. However, experts have worked to make fertilizer use more efficient. Their 4R Nutrient Stewardship approach emphasizes the Right fertilizer source, with the Right amount applied at the Right time in the Right place. Local successes have, however, not improved the environmental situation worldwide. Furthermore, important topics such as fundamental research for instant plant uptake of newly mined and recycled nutrients and breeding to enhance plant 1 For scientific justification see: Bindraban, P.S., et al., Revisiting Fertilizers and Fertilization Strategies for Improved Nutrient Uptake by Plants. Biology and Fertility of Soils, Vol. 51, Issue 8, pp And: Dimkpa, C., Bindraban P.S., Micronutrients fortification for efficient agronomic production. Agronomy for Sustainable Development (2016) 36:1-26. And: 2 Under this term we group the secondary nutrients (calcium (Ca), sulfur (S), magnesium (Mg)), the essential micronutrients (iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), chlorine (Cl), nickel (Ni)) and some nutrients considered non-essential but do stimulate plant growth like (selenium (Se), silicon (Si), cobalt (Co)) Pennsylvania Ave., NW Suite 800 Washington, D.C USA Phone: +1 (202) Fax: +1 (202) contact@vfrc.org

2 nutrient uptake mechanisms or growth processes have received scant attention as integral components toward the design of innovative fertilizer products and technologies. Changing course Environmentally friendly improvements in food and nutritional security require a number of changes. These changes include a novel look at fertilizers and the development of innovative products. Current fertilizers are based on lifeless chemical and physical processes. A new starting point might be to investigate and use living biological and ecological processes. Scientists already know a lot about how plants take up nutrients and how their metabolism turns these into healthy crops. This knowledge, together with future additional insights, could help identify smarter ways to design fertilizers and apply them to plants. The Virtual Fertilizer Research Center (VFRC) envisions a significant opportunity in the addition of micronutrients to fertilizers. These micronutrients boost yields from both poor and several richer soils. Because micronutrients can also improve plants uptake of macronutrients, their use enables reduced application of N, P and K. Increased amounts of micronutrients in plants help them fight diseases and attacks by pests. Importantly, increased micronutrient availability in soils increases nutrient content in crop produce that can ultimately contribute to improved human health. Figure 1. The multiple benefits of micronutrient (MN)-containing fertilizers. The graphs are derived from field data and papers with photo courtesy John Wendt-IFDC, and are meant for illustrative purpose only. Clockwise from upper left: wasting, stunting and underweight as symptoms of malnutrition; crop growth response to MN supply; reduced progression of disease in crops with MN treatment, progressive yield increase with several MN s, increased uptake of NPK with MN, and increase seed nutrient content with MN in the form of salts or nanoparticles. 2

3 Growers in industrial economies today use micronutrients primarily for high-value horticultural and ornamental crops. However, these nutrients are only required in small quantities. There should therefore be an opportunity to use micronutrients in less lucrative food crops as well. Micronutrients have been found to revive yields across a wide range of soils and food crops. There is therefore considerable scope for greater use worldwide. As the addition of micronutrients also gives a better return on NPK investment and water use, it should encourage more farmers in low-income countries to use fertilizer. Micronutrient addition will also help to reduce the application of pesticides and to increase the resilience and sustainability of smallholders production systems. Increasing the (micro)nutrient content of crop produce this way will complement plant breeding with similar aims and offer an alternative to fortified or biofortified processed food. This balanced fertilizer approach would be an important step forward: limited fertilizer use in Africa has left vast amounts of arable land with a serious lack of nutrients. In India, Ethiopia and many other locations, adding micronutrients would help solve a different problem. Farmers there have been using NPK fertilizers for decades, but without replenishing the micronutrients that crops extract from the soil. Appropriate micronutrient-supplemented NPK fertilizer application could help revive the flattening off of yields here and in several other countries. Toward large-scale impact Location-specific targeting: As with N, P and K, however, there is also no standard micronutrient application for all farm conditions. In each situation, researchers and agronomists must pay close attention to a number of factors. These include the exact combination and volume of nutrients that interact best with each soil and plant and the ideal timing of their application. VFRC has embarked on initiatives to answer these questions in quantitative terms. Figure 2 demonstrates a promising result so far. This information will guide farmers on which balanced fertilizer to use and where it is available. The VFRC answers will also guide agro-dealers on where to sell which fertilizer and help policymakers adapt their fertilizer policies for specific regions based on documented need and desired production volume increase. Figure 2. Bean yields in Burundi obtained in on-farm trials at 270 sites with balanced fertilizer application including NPK and micronutrients based on soil information. Yields increased 15 percent on average over recommended fertilization. Map made with advanced spatial statistical methods. Source: IFDC, VFRC, ISRIC, and ISABU. 3

4 Targeted application of micronutrients combined with NPK in on-farm trials show crop yields to increase across different soils and farming systems. For instance, yield increases of percent were observed in Burundi with the existing NPK recommendations, implying proportional increase in uptake efficiency of available NPK. For the existing area under wheat, rice, maize and potatoes, this could mean an additional output of 10, 40, 40 and 140 million tons, respectively. An additional investment of $3-4 million in micronutrients can raise crop income by about $60 million (holding all other factors constant.). Tapping into this potential requires better integrated production and distribution supported by technology scale-up across large areas. Nutrient packaging: It is also essential to package micronutrients in a way that makes them usable by the plant, safer for the environment and affordable to farmers. Research suggests that packaging nutrients in nanoparticles improves their uptake by plants; this approach deserves further investigation. Application of such fertilizers through plant leaves or even fruits may also open up valuable new options. Additional insights could come from the food processing and pharmaceutical industries, who are already experts in packaging active ingredients for faster or slower absorption. Progress in these various disciplines could transform fertilizer production from today s wasteful bulk chemistry into a cleaner high-tech sector. Resource use: The micronutrients for the balanced fertilizers are extracted from ore, but extraction should be minimized because of limited availability. Accumulation in soil and the environment should be prevented and reuse optimized through advanced chemical processing to recapture nutrients from waste to advance toward a recycling-based circular economy. Leapfrog development: As seen with cellular phones or photovoltaic cells, societies can leapfrog development stages seen previously in other parts of the world. Less intensive cable infrastructure is needed for electricity and communication, and developing societies can embrace newest technologies at great convenience and reduced costs. Smart packaging of balanced fertilizers could also help leapfrog constraints in developing countries, such as the difficulty of transporting heavy conventional fertilizers to remote areas. Small amounts through nutrient coated seeds could help kick-start growth and packed as tablets for foliar application or micronutrient-coated granules of NPK to nourish plants could have major growth and yield implications. Balanced fertilizers based on advanced science could quickly become affordable and accessible for poor farmers, while preventing environmental side effects. Human health: Globally, micronutrient malnutrition is known as hidden hunger as the physical signs are not as obvious as the stunting of linear growth and the wasting of muscle and fat or protein energy malnutrition. Iron, zinc, iodine and vitamin A are the most prevalent micronutrient deficiencies. Deficiencies cause blindness (vitamin A), anemia (iron), decreased immunity (vitamin A and zinc) and decreased cognitive development (iron, iodine and zinc). These deficiencies have their greatest impact in the first 1,000 days of life from conception through 24 months of age. Thus, the nutrition of the pregnant woman, the lactating woman and her young child are critically important for assuring a healthy child. Currently, direct supplementation of mothers and children (e.g., vitamin A) and fortification of foods (e.g., iodination of salt) with micronutrients are standard practice. Optimally, mothers and children would obtain the micronutrients directly from diverse diets. The supply of micronutrients to crops increases their nutritional content and therefore offers great potential to help fight hidden hunger. Efficacy trials show that increasing iron, carotene and zinc content 4

5 through plant breeding improves human health. From a physiological perspective, increased plant nutrient content from balanced fertilizers with micronutrients could plausibly have similar effects. Health impacts from fertilizers have been proven for selenium and zinc but need further empirical evidence. The health impact on humans may catalyze policy processes to mandate the use of balanced fertilizers, similar to some countries compulsory fortification of food items. Figure 3. Micronutrient Flow and Fixes: Agriculture-Nutrition-Health Near and long term opportunities The blending of micronutrients to current fertilizers can be done at the immediate term and can enhance yield, nutritional quality and plant health. Demonstration trials can be rolled out for existing fertilizers blended with micronutrients and for current products from high-value markets. Then the uptake efficiency has to be improved by more efficient chemical packaging for environmentally friendly utilization. Incorporating a core of Zn in N-containing urea for instance allows even distribution over blended fertilizers. Industry interest and farmer acquaintance for widespread application can be attained in a few years, for example through extensive demonstrations. More advanced packaging and delivery to plants for immediate uptake such as micronutrient-containing nanoparticles delivered through leaves can be developed simultaneously in a few years. This will optimize nutrient utilization and reduce input requirement in addition to increasing yield, nutritional quality and plant health. Joining forces The comprehensive and innovative approach for advanced packaging and delivery to plants of balanced fertilizers and technologies will create a number of simultaneous benefits. They include: (1) greater incentive for farmers to buy and use fertilizers; (2) increased crop yields and greater food security; (3) nutritionally better food to fight hidden hunger and other dietary problems; (4) fewer losses of NPK fertilizers to the environment and therefore less contribution to climate change, soil degradation or harm to water sources; (5) improved plant and soil health, necessitating lower amounts of pesticides; and (6) increasing resilience of the agricultural system to changing climate. Reaping these benefits requires greater widespread awareness of fertilizers vital role and the possibilities for their improvement. An important step forward would be a new global dialogue and 5

6 dedicated research agenda that also engage partners from outside the traditionally involved agricultural and environmental fields. These partners should include the health sector, the food and chemical industries, as well as national and international development organizations and policy. VFRC fosters the search for innovative fertilizers. It catalyzes processes to integrate the fertilizer research agenda with those of public research institutions and the private sector. For the micronutrients initiative, it will serve both as secretariat and thought leader. VFRC aims to combine insights, align resources and share information on micronutrients in order to address a range of major global issues. References The list of references in support of the statements in the brochure are available on Participating Institutions Micronutrient Initiative China Agricultural University 6

7 7