Mapping of on-field soil nutrient variabilities as a guiding force for Smart farming: A case study from FarmerZone TM sentinel-1 from three potato agroecological zones of India

Abstract

Mapping of soil nutrient parameters using experimental measurements and geostatistical approaches to assist site-specific fertilizer advisories is anticipated to play a significant role in Smart Agriculture. FarmerZone™ is a cloud service envisioned by Department of Biotechnology, Government of India, to provide advisories to assist smallholder farmers in India in enhancing their overall farm production. As a part of the project, we evaluated the soil spatial variability of three potato agroecological zones in India and provided soil health cards along with field-specific fertilizer recommendations for potato cultivation to farmers. Specifically, 705 surface samples were collected from three representative potato-growing districts of Indian states (Punjab, Uttar Pradesh, and Himachal Pradesh) and analysed for soil parameters such as Organic matter, macronutrients (NPK), micronutrients (Zn, Fe, Mn, and Cu), pH, and EC. The soil parameters were integrated into a geodatabase and subjected to Kriging interpolation to create spatial soil maps of the targeted potato agroecological zones through best-fit experimental semivariograms. The NPK spatial distribution showed a deficiency of soil organic matter and available Nitrogen among all studied zones, whereas available Phosphorus and Potassium ranged from low to medium in the central plain zone and from medium to high in the Northwestern plain and high hilly zone. The availability of micronutrients was largely sufficient in all the zones except at a few sites. This study supports the role of site-specific soil analytics and interpolated spatial soil mapping over agroecological zones as a promising source to deliver reliable advisories of fertilizer recommendations.