Foliar micronutrient addition for healthier rice

Targeted nutrients for stronger crops and richer grain

Foliar micronutrient addition is a targeted approach to addressing deficiencies in rice crops by applying liquid fertilizers containing essential trace elements such as zinc, copper, manganese, and boron directly onto the leaves and stems. The technique ensures rapid absorption of nutrients during critical growth stages, such as flowering and grain filling. This method improves nutrient uptake efficiency since smaller quantities of fertilizer are required compared to soil application. Farmers use knapsack sprayers or tractor-mounted equipment to uniformly distribute diluted micronutrient solutions over the rice canopy. The application typically begins 6 to 8 weeks after planting and continues at key points in the crop cycle. By improving grain quality, yield, and crop resilience to diseases, this technology enhances both the market value and productivity of rice crops in areas where soil nutrient depletion is common.

This technology is TAAT1 validated.

8•8

Scaling readiness: idea maturity 8/9; level of use 8/9

Adults 18 and over: Positive high

Adults, especially farmers, will benefit significantly from increased rice yields, improved grain quality, and higher incomes, making the impact highly positive.

The poor: Positive low

While the technology can lead to better yields and incomes, its initial costs for fertilizers and equipment may limit adoption among poorer farmers.

Under 18: No impact

Children under 18 are unlikely to be directly impacted, as they do not typically participate in decisions about agricultural practices or technology adoption.

Women: Positive medium

Women, who often engage in farming and household food production, will experience positive impacts through improved crop yields and nutritional quality. However, access to the technology might be limited in some regions, slightly moderating the impact.

Climate adaptability: Moderately adaptable

This technology can be applied in various climates, but its efficiency may vary depending on the specific micronutrient needs and environmental conditions in different regions. While adaptable, it requires targeted application for best results, leading to a moderate rating.

Farmer climate change readiness: Significant improvement

The technology helps farmers adapt to climate change by improving nutrient management and crop resilience, leading to better yields even under changing environmental conditions. This justifies a significant positive impact.

Biodiversity: No impact on biodiversity

Carbon footprint: Same amount of carbon released

Environmental health: Does not improve environmental health

Soil quality: Does not affect soil health and fertility

Water use: A bit less water used

Since foliar application reduces the need for excessive soil-based fertilizer use, it may result in slightly more efficient water use, leading to a small reduction in water consumption.

Problem

Micronutrient Deficiencies: Rice crops often lack essential micronutrients like zinc, copper, and boron.
Low Rice Yields: Many farmers experience low yields due to inadequate nutrient availability.
Poor Grain Nutrition: Grains often lack nutritional quality because of nutrient-deficient soils.
Soil Nutrient Depletion: Soils in Sub-Saharan Africa are increasingly depleted of vital nutrients.
Inefficient Nutrient Uptake: Traditional soil-based fertilizers lead to inefficient nutrient absorption by plants.
Crop Vulnerability: Crops are more susceptible to diseases and environmental stresses without adequate nutrients.

Solution

Targeted Micronutrient Application: Spraying essential micronutrients like zinc, copper, and boron directly onto leaves addresses deficiencies and enhances nutrient availability.
Increased Yields and Grain Quality: Improving nutrient uptake leads to higher rice yields and better nutritional quality in grains.
Soil Health Improvement: Supplementing with foliar micronutrients helps counteract soil nutrient depletion.
Efficient Nutrient Uptake: Direct application maximizes absorption efficiency, using smaller quantities of fertilizer.
Enhanced Crop Resilience: Providing essential nutrients strengthens crops against diseases and environmental stress.

Key points to design your project

This technology, focusing on rice cultivation, addresses the challenge of low micronutrient content in rice, a common issue in Sub-Saharan Africa due to depleted soils. By employing a practical and cost-effective approach of spraying specialty liquid mixes of micronutrient fertilizer on rice crops. This not only enhances grain yield and nutritional value but also contributes to sustainable agriculture, aligning with goals for food security, poverty reduction, and environmental sustainability.

To integrate this technology into your project, create a list of project activities and prerequisites, including:

Informing rice farmers and agrodealers about the higher production level and market value of grain that can be achieved through foliar micronutrient addition,
Assessing the specific micronutrient deficiencies and imbalances in rice paddies that limit grain yield and nutritional value,
Formulating appropriate rates, mixes and schedules for foliar micronutrient application at critical stages of the production cycle,
Providing cash or credit to purchase of specialty fertilizer, and hire manual or tractor mounted sprayers for application on rice paddies.

- Estimate the quantity of mineral fertilizers, and tractor mounted sprayers needed for your project.

- As the technology is available in Zimbabwe, Zambia, Uganda, Togo, Tanzania, Senegal, Rwanda, Nigeria, Niger, Mozambique, Malawi, Madagascar, Kenya, Ivory Coast, Ghana, Ethiopia, Democratic Republic of the Congo, Cameroon, Burundi, Burkina Faso, Benin, include the delivery cost to the project site and account for import clearance and duties if relevant.

Consider also:

The cost per kilogram of microelement in fertilizers amounts to: 4.3 USD (sulfate), 16.2 USD (zinc chelate), 6.0 USD (iron sulfate), 6.2 USD (sodium pentaborate) and 14.6 USD (copper sulfate).
Protective kits for one person at 40 USD
Top-quality agricultural knapsack sprayers with a tank of 20 liter are sold at 30 to 45 USD, and
Renting tractor-mountable sprayers costs approximately 100 to 300USD per hour and 1-3 hectares of rice paddies can be treated in one hour.

Training is important. A team of trainers could provide training and support during project installation. Include the cost for training and post-training support for using the technology.

Communication support for the technology should be developed (flyers, videos, radio broadcasts, etc.)

For better optimization of this technology, it is recommended to associate this technology with New Rice for Africa (NERICA), Hybrid Rice Varieties for Africa (ARICA), Mineral fertilizers with nitrogen, phosphorus and potassium.

To implement the technology in your country, you could collaborate with agricultural development institutes, Fertilizer suppliers, and Agricultural service companies.

Cost: $$$ 41.1 USD

Fertilizers

ROI: $$$ 7—30 %

Yield increased

40 USD

Protective kits per person

30—45 USD

Knapsack sprayers with a tank of 20 liter

IP

Open source / open access

Countries with a green colour: Tested & adopted
Countries with a bright green colour: Adopted
Countries with a yellow colour: Tested

Countries where the technology has been tested and adopted
Country	Tested	Adopted
Benin	Tested	Adopted
Burkina Faso	Tested	Adopted
Burundi	Tested	Adopted
Cameroon	Tested	Adopted
Côte d’Ivoire	Tested	Adopted
Democratic Republic of the Congo	Tested	Adopted
Ethiopia	Tested	Adopted
Ghana	Tested	Adopted
Kenya	Tested	Adopted
Madagascar	Tested	Adopted
Malawi	Tested	Adopted
Mozambique	Tested	Adopted
Niger	Tested	Adopted
Nigeria	Tested	Adopted
Rwanda	Tested	Adopted
Senegal	Tested	Adopted
Tanzania	Tested	Adopted
Togo	Tested	Adopted
Uganda	Tested	Adopted
Zambia	Tested	Adopted
Zimbabwe	Tested	Adopted

This technology can be used in the colored agro-ecological zones. Any zones shown in white are not suitable for this technology.

Agro-ecological zones where this technology can be used
AEZ	Subtropic - warm	Subtropic - cool	Tropic - warm	Tropic - cool
Arid	–	–	–	–
Semiarid	–	–	–	–
Subhumid				–
Humid				–

Source: HarvestChoice/IFPRI 2009

The United Nations Sustainable Development Goals that are applicable to this technology.

Goal 2: zero hunger

By addressing micronutrient deficiencies, the technology helps increase rice yields and improve grain quality, contributing to food security and better nutrition. This significantly supports efforts to reduce hunger and malnutrition.

Goal 1: no poverty

The technology boosts farmer income by improving crop productivity and quality, but the initial costs for micronutrient fertilizers may limit its immediate accessibility for poorer farmers. However, in the long term, it has potential to alleviate poverty through increased agricultural profitability.

Goal 12: responsible production and consumption

The technology promotes more efficient use of agricultural inputs like fertilizers, reducing waste and improving nutrient uptake efficiency. This aligns with the goal of promoting sustainable production practices.

Goal 13: climate action

By making crops more resilient to environmental stressors and improving nutrient management, the technology helps farmers adapt to climate change. While it doesn’t directly reduce emissions, it enhances agricultural sustainability in the face of changing climates.

Selection: Choose the right foliar micronutrient solution tailored for rice crops, ensuring it contains essential elements like magnesium, calcium, copper, zinc, manganese, and boron.
Safety: Wear appropriate protective equipment during application to prevent any potential health risks, especially if the solution contains additional chemicals or pesticides.
Timing: Apply the solution at the appropriate growth stage of the rice, preferably when the plant leaves are most receptive, typically six to eight weeks after planting or at critical growth stages.
Dilution: Dilute the concentrated solution as recommended, ensuring the correct concentration for optimal uptake by the plants.
Application: Using a sprayer, evenly spray the solution onto the rice canopy. Ensure the droplets are fine for maximum absorption. A nebulizer sprayer can be particularly effective.
Coverage: Ensure complete coverage of all plant leaves, as this is where absorption primarily takes place.