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Tag: nutrient use efficiency

Digital nutrient management tool reduces emissions, improves crop yields and boosts farmers’ profits

Written by Alison Doody on . Posted in News.

A farmer in the Ara district, in India's Bihar state, applies NPK fertilizer, composed primarily of nitrogen, phosphorus and potassium. (Photo: Dakshinamurthy Vedachalam/CIMMYT)
A farmer in the Ara district, in India’s Bihar state, applies NPK fertilizer, composed primarily of nitrogen, phosphorus and potassium. (Photo: Dakshinamurthy Vedachalam/CIMMYT)

An international team of scientists, led by the International Maize and Wheat Improvement Center (CIMMYT), has demonstrated how better nutrient management using digital tools, such as the Nutrient Expert decision support tool, can boost rice and wheat productivity and increase farmers’ income while reducing chemical fertilizer use and greenhouse gas emissions.

Reported today in Nature Scientific Reports, the results show how the farmer-friendly digital nutrient management tool can play a key role in fighting climate change while closing the yield gap and boosting farmers’ profits.

The researchers tested the Nutrient Expert decision tool against typical farmer fertilization practices extensively using approximately 1600 side-by side comparison trials in rice and wheat fields across the Indo-Gangetic Plains of India.

The study found that Nutrient Expert-based recommendations lowered global warming potential by 12-20% in wheat and by around 2.5% in rice, compared to conventional farmers’ fertilization practices. Over 80% of farmers were also able to increase their crop yields and incomes using the tool.

Agriculture is the second largest contributor of greenhouse gas emissions in India. To tackle these emissions, crop scientists have been working on new ways to make farming more nutrient- and energy-efficient. Of the many technologies available, improving nutrient-use-efficiency through balanced fertilizer application — which in turn reduces excess fertilizer application — is key to ensuring food security while at the same time contributing to the UN’s Sustainable Development Goals on climate change.

The work was carried out by CIMMYT in collaboration with farmers, and funded by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), the CGIAR Research Program on Wheat (WHEAT), and the Indian Council of Agricultural Research (ICAR). Scientists from the Borlaug Institute for South Asia (BISA), the International Rice Research Institute (IRRI), the Alliance of Bioversity International and CIAT, and the former International Plant Nutrition Institute (IPNI) also contributed to this study.

Researchers tested the Nutrient Expert decision tool against typical farmer fertilization practices extensively using approximately 1600 side-by side comparison trials in rice and wheat fields across the Indo-Gangetic Plains of India (Graphic: CIMMYT).
Researchers tested the Nutrient Expert decision tool against typical farmer fertilization practices extensively using approximately 1600 side-by side comparison trials in rice and wheat fields across the Indo-Gangetic Plains of India (Graphic: CIMMYT).

Precise recommendations

Nutrient Expert, which was launched back in 2013, works by analysing growing conditions, natural nutrients in the soil, and even leftover nutrients from previous crops to provide tailored fertilizer recommendations directly to farmers phones. The tool also complements the Government of India’s Soil Health Cards for balanced and precise nutrient recommendations in smallholder farmers’ fields.

Each farmer’s field is different, which is why blanket fertilizer recommendations aren’t always effective in producing better yields. By using nutrient management tools such as Nutrient Expert, farmers can obtain fertilizer recommendations specific to the conditions of their field as well as their economic resources and thus avoid under-fertilizing or over-fertilizing their fields.

“While efficient nutrient management in croplands is widely recognized as one of the solutions to addressing the global challenge of supporting food security in a growing global population while safeguarding planetary health, Nutrient Expert could be an important tool to implement such efficient nutrient management digitally under smallholder production systems,” said Tek Sapkota, CIMMYT climate scientist and first author of the study.

Sapkota also argues that adoption of the Nutrient Expert tool in rice-wheat systems of India alone could provide almost 14 million tonnes (Mt) of extra grain with 1.4 Mt less nitrogen fertilizer use, and a reduction of 5.3 Mt of carbon (CO2) emissions per year over current practices.

However, technological innovation alone will not achieve these positive outcomes.

“Given the magnitude of potential implications in terms of increasing yield, reducing fertilizer consumption and greenhouse gas emissions, governments need to scale-out Nutrient Expert-based fertilizer management through proper policy and institutional arrangements, especially for making efficient use of the nearly 200 million Soil Health Cards that were issued to farmers as part of the Soil Health mission of the Government of India,” said ML Jat, CIMMYT principal scientist and co-author of the study.

Read the study:
Crop nutrient management using Nutrient Expert improves yield, increases farmers’ income and reduces greenhouse gas emissions.

In Ethiopia, scattered trees in crop fields have been practiced for centuries. (Photo: Tesfaye Shiferaw /CIMMYT)

Matching nutrients to agroforestry systems for greater maize and wheat yields

Written by Marta Millere on . Posted in Features.

Globally, the COVID-19 pandemic and associated lockdowns have created bottlenecks across the agricultural value chain, including disrupting the supply of fertilizer. This could negatively impact the already low yields in smallholders’ fields in the Global South. Livelihoods of these resource-poor farmers and food security of those they feed call for innovations or smarter application of existing knowledge to avoid increasing food insecurity.

In a recent study, a team of scientists from the International Maize and Wheat Improvement Center (CIMMYT) and Plant Production Systems, Wageningen University, found that there are clever ways to mix and match maize and wheat varieties with mineral fertilizers in tree-crop systems for greater nutrient use efficiency. The study explored the impact of different combinations of nitrogen (N) and phosphorus (P) fertilizers on crop yield in tree crop systems. It also identified mineral fertilizer-tree combinations that maximize agronomic nutrient use efficiencies under different contexts.

Tree-crop-fertilizer interactions for wheat growing under Faidherbia albida and maize growing under Acacia tortilis and Grevillea robusta through omission trials of N and P were explored in open fields and fields under tree canopy, using a split plot design. The experiments were conducted under different agroecologies in Ethiopia (Meki and Mojo) and Rwanda, where retaining scattered trees in fields has been practiced for centuries. The trials were replicated four times and over two seasons. Trees with approximately similar ages, crown structures and pruning history were used for a researcher-led and farmer-managed on-farm experiment.

The results demonstrated that different on-farm tree species interact uniquely with crops, resulting in different responses to N and P fertilization. Except for F. albida, perhaps the most ‘ideal’ agroforestry species, the other two tree species under the current study raised the question of tree-crop compatibility for optimum productivity. F. albida significantly improved N and P use efficiencies, leading to significantly higher grain yields in wheat. The P use efficiency of wheat under F.albida was double that of wheat grown in an open field. By contrast, G. robusta and A. tortilis trees lowered nutrient use efficiencies in maize, leading to significantly less maize grain yields compared with open fields receiving the same fertilization. The case study also identified probabilities of critically low crop yields and crop failure to be significantly greater for maize growing under the canopy of these species.

A tree-crop system in Ethiopia. (Photo: Tesfaye Shiferaw /CIMMYT)
A tree-crop system in Ethiopia. (Photo: Tesfaye Shiferaw /CIMMYT)

In conclusion, the study demonstrated that tree-crop interactions are mediated by the application of N and P fertilizers in tree-crop systems. In F. albida-wheat agroforestry systems, N fertilizers could be saved, with localized application of P fertilizers close to tree crowns. Such adaptable application may help smallholder farmers cope with COVID-19-imposed fertilizer limitations. In G.robusta-maize and A.tortilis-maize agroforestry systems, maize did not respond to N and P fertilizers applied at recommended rates, although the application of these nutrients compensated for competition. This implies mineral fertilizers can offset the effect of competition, while they fail to provide the yield advantages like mono-cropping situations.

The researchers underlined the fact that fertilizer recommendations need to be adapted to agroforestry systems. However, in order to quantify the exact magnitude and nature of fertilizer-tree interaction in agroforestry systems accurately, factorial application of higher and lower rates of mineral fertilizer is needed. They also called for further research to identify fertilization rates that minimize tree-crop competition for G. robusta-maize and A. tortilis-maize systems, while additional studies are needed to identify the rates and timing of application that optimize F. albida-wheat facilitation.

This work was carried out by the International Maize and Wheat Improvement Center (CIMMYT) and Plant Production Systems, Wageningen University

Download your copy of the publication: Should fertilizer recommendations be adapted to parkland agroforestry systems? Case studies from Ethiopia and Rwanda

Hafiz Uddin, a farmer from Ulankhati, Tanpuna, Barisal, Bangladesh. He used seeder fertilizer drills to plant mung beans on one acre of land, which resulted in a better yield than planting manually. (Photo: Ranak Martin)

Policy brief highlights opportunities to promote balanced nutrient management in South Asia

Written by Matthew O'Leary on . Posted in Publications.

Hafiz Uddin, a farmer from Ulankhati, Tanpuna, Barisal, Bangladesh. He used seeder fertilizer drills to plant mung beans on one acre of land, which resulted in a better yield than planting manually. (Photo: Ranak Martin)
Hafiz Uddin, a farmer from Ulankhati, Tanpuna, Barisal, Bangladesh. He used seeder fertilizer drills to plant mung beans on one acre of land, which resulted in a better yield than planting manually. (Photo: Ranak Martin)

Over the last few decades, deteriorating soil fertility has been linked to decreasing agricultural yields in South Asia, a region marked by inequities in food and nutritional security.

As the demand for fertilizers grows, researchers are working with government and businesses to promote balanced nutrient management and the appropriate use of organic amendments among smallholder farmers. The Cereal Systems Initiative for South Asia (CSISA) has published a new policy brief outlining opportunities for innovation in the region.

Like all living organisms, crops need access to the right amount of nutrients for optimal growth. Plants get nutrients — like nitrogen, phosphorus, and potassium, in addition to other crucially important micronutrients — from soils and carbon, hydrogen, oxygen from the air and water. When existing soil nutrients are not sufficient to sustain good crop yields, additional nutrients must be added through fertilizers or manures, compost or crop residues. When this is not done, farmers effectively mine the soil of fertility, producing short-term gains, but undermining long-term sustainability.

Nutrient management involves using crop nutrients as efficiently as possible to improve productivity while reducing costs for farmers, and also protecting the environment by limiting greenhouse gas emissions and water quality contamination. The key behind nutrient management is appropriately balancing soil nutrient inputs — which can be enhanced when combined with appropriate soil organic matter management — with crop requirements. When the right quantities are applied at the right times, added nutrients help crops yields flourish. On the other hand, applying too little will limit yield and applying too much can harm the environment, while also compromising farmers’ ability to feed themselves or turn profits from the crops they grow.

Smallholder farmers in South Asia commonly practice poor nutrition management with a heavy reliance on nitrogenous fertilizer and a lack of balanced inputs and micronutrients. Declining soil fertility, improperly designed policy and nutrient management guidelines, and weak fertilizer marketing and distribution problems are among the reasons farmers fail to improve fertility on their farms. This is why it is imperative to support efforts to improve soil organic matter management and foster innovation in the fertilizer industry, and find innovative ways to target farmers, provide extension services and communicate messages on cost-effective and more sustainable strategies for matching high yields with appropriate nutrient management.

Cross-country learning reveals opportunities for improved nutrient management. The policy brief is based on outcomes from a cross-country dialogue facilitated by CSISA earlier this year in Kathmandu. The meeting saw researchers, government and business stakeholders from Bangladesh, India, Nepal, and Sri Lanka discuss challenges and opportunities to improving farmer knowledge and access to sufficient nutrients. Several key outcomes for policy makers and representatives of the agricultural development sector were identified during the workshop, and are included in the brief.

Extension services as an effective way to encourage a more balanced use of fertilizers among smallholder farmers. There is a need to build the capacity of extension to educate smallholders on a plant’s nutritional needs and proper fertilization. It also details how farmers’ needs assessments and human-centered design approaches need to be integrated while developing and delivering nutrient application recommendations and extension materials.

Nutrient subsidies must be reviewed to ensure they balance micro and macro-nutrients. Cross-country learning and evidence sharing on policies and subsidies to promote balanced nutrient application are discussed in the brief, as is the need to balance micro and macro-nutrient subsidies, in addition to the organization of subsidy programs in ways that assure farmers get access the right nutrients when and where they are needed the most. The brief also suggests additional research and evidence are needed to identify ways to assure that farmers’ behavior changes in response to subsidy programs.

Market, policy, and product innovations in the fertilizer industry must be encouraged. It describes the need for blended fertilizer products and programs to support them. A blend is made by mixing two or more fertilizer materials. For example, particles of nitrogen, phosphate and small amounts of secondary nutrients and micronutrients mixed together. Experience with blended products are uneven in the region, and markets for blends are nascent in Bangladesh and Nepal in particular. Cross-country technical support on how to develop blending factories and markets could be leveraged to accelerate blended fertilizer markets and to identify ways to ensure equitable access to these potentially beneficial products for smallholder farmers.

Download the CSISA Policy and Research Note:
Development of Balanced Nutrient Management Innovations in South Asia: Lessons from Bangladesh, India, Nepal, and Sri Lanka.

The CSISA project is led by CIMMYT with partners the International Rice Research Institute (IRRI) and the International Food Policy Research Institute (IFPRI) and funded by the U.S. Agency for International Development and the Bill & Melinda Gates Foundation.