GFAR blog

Digital soil map provides information for crop productivity and soil health

By the International Maize and Wheat Improvement Center (CIMMYT)

A digital soil map for Nepal launched in 2021 provides access to location-specific information on soil properties for any province, district, municipality or a particular area of interest. The interactive map provides information useful for new crop- and site-specific fertilizer recommendations for the country.

Produced by the International Maize and Wheat Improvement Center (CIMMYT), in collaboration with Nepal Agricultural Research Council’s (NARC) National Soil Science Research Center (NSSRC), the digital soil map is the first publicly available soil map in South Asia that covers the entire country.

At the official launch event for the map in February 2021 the Prime Minister of Nepal, K.P. Sharma Oli highlighted the benefits the map would bring to support soil fertility management in the digital era in Nepal.

CIMMYT, NSSRC and Department of Agriculture’s Centre for Crop Development and Agrobiodiversity Conservation (CCDABC) piloted the digital soil map to estimate the fertilizer requirement for rice, wheat and maize in Bardiya district in September 2021.

Since its launch, the web portal which hosts the map has been visited 4,613 times with 16,209 impressions, i.e. the number of times users search the link on search engines. Now, the portal has 252 registered users who have downloaded soil properties 1,340 times. Approximately 447 requests for accessing data via APIs have been received.

Better decisions

Farm workers Ramnaresh Thakur and Bihari Banjara help tractor driver Santosh Kumari Yadav direct seed in Hasnapurkatti, Bardiya, Nepal. Credit: P. Lowe/CIMMYT.

The new online resource was prepared using soil information from 23,273 soil samples collected from the National Land Use Project, Central Agricultural Laboratory and Nepal Agricultural Research Council. The samples were collected from 56 districts covering seven provinces. These soil properties were combined with environmental covariates (soil forming factors) derived from satellite data and spatial predictions of soil properties were generated using advanced machine learning tools and methods.

The platform is hosted and managed by NARC, whose staff update the database periodically to ensure its effective management, accuracy and use by local government and relevant stakeholders. The first version of the map was finalized and validated through a workshop organized by NSSRC among different stakeholders, including retired soil scientists and university professors.

“The ministry can use the map to make more efficient management decisions on import, distribution and recommendation of appropriate fertilizer types, including blended fertilizers. The same information will also support provincial governments to select suitable crops and design extension programs for improving soil health,” said Padma Kumari Aryal, Minister of Agriculture and Livestock Development.

“The private sector can utilize the acquired soil information to build interactive and user-friendly mobile apps that can provide soil properties and fertilizer-related information to farmers as part of commercial agri-advisory extension services,” she said.

“These soil maps will not only help to increase crop yields, but also the nutritional value of these crops, which in return will help solve problems of public health such as zinc deficiency in Nepal’s population,” explained Ivan Ortiz-Monasterio, principal scientist at CIMMYT.

Benefits of digital soil mapping

Lead farmer Santa Bhandari harvests green maize for her buffaloes in Neulapur, Bardiya, Nepal. Credit: P. Lowe/CIMMYT

Soil properties affect crop yield and production. In Nepal, access to soil testing facilities is scarce, making it difficult for farmers to know the fertilizer requirement of their land. A well-developed soil information system with soil fertility maps has been lacking for decades, leading to inadequate strategies for soil fertility and fertilizer management.  Existing blanket-type fertilizer recommendations lead to imbalanced application of plant nutrients and fertilizers, negatively affecting both crop productivity and soil health.

This is where digital soil mapping comes in handy. It allows users to identify a domain with similar soil properties and soil fertility status. The digital platform provides access to domain-specific information on soil properties including soil texture, soil pH, organic matter, nitrogen, available phosphorus and potassium, and micronutrients such as zinc and boron across Nepal’s arable land.

Farmers and extension agents can now estimate the total amount of fertilizer required for a particular domain or season. Using the map a decision-support tool, policy makers and provincial government can design and implement programs for improving soil fertility and increasing crop productivity.

PlantSat — a mobile app that uses satellite data for agro-advisory  — is experimenting with their app to load soil data directly for the web portal. In Nepal, faculties of Paklihawa Campus, Tribhuvan University, and Institute of Agriculture and Animal Science in Rupandehi district also used the soil data from the digital map to study the land suitability for different crop patterns in Palpa district.

The map also allows users to identify areas with deficient plant nutrients and provide site-specific fertilizer formulations; for example, determining the right type of blended fertilizers required for balanced fertilization programs. Periodic updates from these soil maps can also serve as an educational resource for students.

Nepal’s digital soil map is readily accessible on the NSSRC web portal:

This blog is part of the GFAR Partners in Action series, celebrating the achievements of our diverse network of partners who are working together to shape a new, sustainable future for agriculture and food. Each month we will be showcasing stories related to a key theme in agri-food research and innovation. The theme for January is ‘Soil and land data to support improved sustainability and FAIR access’.

Join the conversation in the comments below or share this article on social media using #GFARinAction.

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