Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Responses of two sweet potato clones to bed and nutrient management in Satkhira, Bangladesh

University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Germany

Abstract

In coastal Bangladesh, salinity and waterlogging from rising sea levels and erratic precipitation threaten sweet potato production and, thus, smallholder livelihoods. The objective of this study was to evaluate the effects of different bed systems (flat, raised, furrow) combined with three nutrient managements (BARI recommended dose, BARI recommended dose + biochar, and Integrated Plant Nutrient System) on flooding and salt stress resilience of two sweet potato breeding lines, H.9.48/11 (V1) and H.9.7/12 (V2).
At the BARI (Bangladesh Agriculture Research Institute) Satkhira research station, during the first week of July 2024, we implemented a split–split–plot design with 3 replicates. Morpho physiological traits (vine length, number of leaves, young and total leaf area, total leaf dry weight, young leaf dry weight, side branch length, side branch leaf area, specific leaf area, SPAD chlorophyll content, relative water content, leaf Na⁺/K⁺ ratio) and soil parameters (pH, electrical conductivity, moisture) were measured at 30 days after sowing and at 14-day intervals thereafter.
Preliminary results indicate that the responses of the two sweet potato clones to the bed systems and nutrient management strategies were significantly different. V2 (H.9.7/12) consistently outperformed V1 (H.9.48/11) under all treatments, showing greater resilience to salinity and waterlogging stress. For example, V2 in raised beds with BARI recommended dose + biochar increased total leaf area by 28%, maintained SPAD values 15% higher, improved relative water content by 12%, and reduced leaf Na⁺ by 22% compared to V1. Control treatments, including V1, flat beds, and BARI recommended dose, showed less improvement. Flat beds reduced total leaf area by 15% compared to raised beds, and BARI recommended dose alone did not significantly improve stress tolerance. Furrow beds, particularly with the Integrated Plant Nutrient System, did not significantly outperform the controls in leaf area or chlorophyll content.
These results suggest that combining a stress-tolerant genotype with raised bedding and optional soil enrichment through biochar may offer a robust strategy for mitigating combined salinity and waterlogging stresses in coastal sweet potato cultivation.
Detailed analysis, including ANOVA and post-hoc results, will be presented at the conference.

Keywords: Biochar amendment, coastal agriculture, flood tolerance, salinity management

Contact Address: Dayasagar Koyyada, University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Garbenstr. 13, 70599 Stuttgart, Germany, e-mail: dayasagar.koyyadauni-hohenheim.de