Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda

Soil fertility limits potato yield in Rwanda. While research towards site-specific fertilizer recommendations for macronutrients (N, P, and K) is ongoing, little is known about secondary macronutrient (Ca, Mg, and S) and micronutrient (B, Fe, Mn, Zn Cu, Mo, and Ni) status in Rwanda. Hence, the aim o...

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Autor principal: Mahieu, S.
Formato: Tesis
Lenguaje:Inglés
Publicado: 2024
Materias:
Acceso en línea:https://hdl.handle.net/10568/169336
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author Mahieu, S.
author_browse Mahieu, S.
author_facet Mahieu, S.
author_sort Mahieu, S.
collection Repository of Agricultural Research Outputs (CGSpace)
description Soil fertility limits potato yield in Rwanda. While research towards site-specific fertilizer recommendations for macronutrients (N, P, and K) is ongoing, little is known about secondary macronutrient (Ca, Mg, and S) and micronutrient (B, Fe, Mn, Zn Cu, Mo, and Ni) status in Rwanda. Hence, the aim of this thesis was to investigate the prevalence of secondary macronutrient and micronutrient deficiencies in potato in Rwanda, focusing on site-specific fertilizer validation trials in the agro-ecological zones Birunga, Buberuka Highlands, and Congo-Nile Divide. Potato leave samples were taken on 84 plots during the onset of tuberization and tuber bulking stage, which were analysed for P, K, Ca, Mg, S, B, Fe, Mn, Zn, Cu, Mo, and Ni concentration. The results were compared with critical nutrient concentrations to assess the number of plots with deficiencies. From these same plots, soil samples were taken during the onset of tuberization and analysed for pH, eCEC and exchangeable K, Ca, Mg, and Na. As such, deficiencies could be linked with soil characteristics and trial management data to predict secondary macronutrient and micronutrient deficiencies in different locations. At the onset of tuberization in Birunga, Buberuka Highlands and Congo-Nile Divide, deficiencies were found for Ca in 61, 96, and 87% of plots, for Mg in 0, 2 and 29% of plots, for B in 0, 5.4, and 50% of plots, and for Mn in 18, 23 and 16% of plots, respectively. During tuber bulking, deficiencies were found for Zn in 21, 60, and 5% of plots, and for Cu in 41, 5 and 2% of plots, respectively. Deficiencies of S, Fe, Mo, and Ni were negligible in each agro-ecological zone. Principal component regression with the measured soil characteristics, supplemented by the agro-ecological zones and trial management practices, was performed to predict the concentrations of Ca, Mg, B, Mn, Zn, and Cu. Plant Ca and Mg concentrations were mainly predicted by exchangeable Ca and Mg concentrations and organic matter application. Plant B concentrations were mainly predicted by agro-ecological zone, soil pH, and crop residue removal. Plant Mn concentrations were mainly elevated by application of a Mn-containing fungicide. Plant Zn concentrations were mainly predicted by exchangeable bases and agro-ecological zone. Plant Cu concentrations were mainly predicted by agro-ecological zone. The results can later be linked with digital soil maps to predict deficiencies in other locations. Site-specific application of the deficient secondary macronutrients and micronutrients can then improve NPK fertilizer efficiency and increase potato yields.
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spelling CGSpace1693362025-01-17T15:21:36Z Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda Mahieu, S. soil fertility nutrient deficiencies potatoes Soil fertility limits potato yield in Rwanda. While research towards site-specific fertilizer recommendations for macronutrients (N, P, and K) is ongoing, little is known about secondary macronutrient (Ca, Mg, and S) and micronutrient (B, Fe, Mn, Zn Cu, Mo, and Ni) status in Rwanda. Hence, the aim of this thesis was to investigate the prevalence of secondary macronutrient and micronutrient deficiencies in potato in Rwanda, focusing on site-specific fertilizer validation trials in the agro-ecological zones Birunga, Buberuka Highlands, and Congo-Nile Divide. Potato leave samples were taken on 84 plots during the onset of tuberization and tuber bulking stage, which were analysed for P, K, Ca, Mg, S, B, Fe, Mn, Zn, Cu, Mo, and Ni concentration. The results were compared with critical nutrient concentrations to assess the number of plots with deficiencies. From these same plots, soil samples were taken during the onset of tuberization and analysed for pH, eCEC and exchangeable K, Ca, Mg, and Na. As such, deficiencies could be linked with soil characteristics and trial management data to predict secondary macronutrient and micronutrient deficiencies in different locations. At the onset of tuberization in Birunga, Buberuka Highlands and Congo-Nile Divide, deficiencies were found for Ca in 61, 96, and 87% of plots, for Mg in 0, 2 and 29% of plots, for B in 0, 5.4, and 50% of plots, and for Mn in 18, 23 and 16% of plots, respectively. During tuber bulking, deficiencies were found for Zn in 21, 60, and 5% of plots, and for Cu in 41, 5 and 2% of plots, respectively. Deficiencies of S, Fe, Mo, and Ni were negligible in each agro-ecological zone. Principal component regression with the measured soil characteristics, supplemented by the agro-ecological zones and trial management practices, was performed to predict the concentrations of Ca, Mg, B, Mn, Zn, and Cu. Plant Ca and Mg concentrations were mainly predicted by exchangeable Ca and Mg concentrations and organic matter application. Plant B concentrations were mainly predicted by agro-ecological zone, soil pH, and crop residue removal. Plant Mn concentrations were mainly elevated by application of a Mn-containing fungicide. Plant Zn concentrations were mainly predicted by exchangeable bases and agro-ecological zone. Plant Cu concentrations were mainly predicted by agro-ecological zone. The results can later be linked with digital soil maps to predict deficiencies in other locations. Site-specific application of the deficient secondary macronutrients and micronutrients can then improve NPK fertilizer efficiency and increase potato yields. 2024-06 2025-01-17T14:59:43Z 2025-01-17T14:59:43Z Thesis https://hdl.handle.net/10568/169336 en https://repository.teneo.libis.be/delivery/DeliveryManagerServlet?dps_pid=IE19286388& Open Access Mahieu, S. 2024. Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda. Master’s thesis. University of Leuven. 121 p.
spellingShingle soil fertility
nutrient deficiencies
potatoes
Mahieu, S.
Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda
title Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda
title_full Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda
title_fullStr Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda
title_full_unstemmed Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda
title_short Predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site-specific fertilizer recommendations in Rwanda
title_sort predicting the impact of secondary macronutrient and micronutrient deficiencies on the responses of potato to site specific fertilizer recommendations in rwanda
topic soil fertility
nutrient deficiencies
potatoes
url https://hdl.handle.net/10568/169336
work_keys_str_mv AT mahieus predictingtheimpactofsecondarymacronutrientandmicronutrientdeficienciesontheresponsesofpotatotositespecificfertilizerrecommendationsinrwanda