Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize
Applying starter nitrogen (N) and potassium (K) fertilizers in a pop-up placement directly in the maize seed furrow is a delicate practice due to the direct contact between fertilizers and seeds. This proximity increases the risk of seed damage caused by the salinity of N and K fertilizers and the a...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-08-01
|
| Series: | Frontiers in Agronomy |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fagro.2025.1543564/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849339918760804352 |
|---|---|
| author | William Makaza William Makaza Lotfi Khiari Lotfi Khiari Mounir El Achaby |
| author_facet | William Makaza William Makaza Lotfi Khiari Lotfi Khiari Mounir El Achaby |
| author_sort | William Makaza |
| collection | DOAJ |
| description | Applying starter nitrogen (N) and potassium (K) fertilizers in a pop-up placement directly in the maize seed furrow is a delicate practice due to the direct contact between fertilizers and seeds. This proximity increases the risk of seed damage caused by the salinity of N and K fertilizers and the ammoniacal toxicity of nitrogen fertilizers. This study aims to determine the safe application rates of four commonly used starter fertilizers: monoammonium phosphate (MAP: NH4H2PO4), diammonium phosphate (DAP: (NH4)2HPO4), potassium chloride (KCl), and potassium sulfate (K2SO4) across three soil textures: fine (G1), medium (G2), and coarse (G3). A greenhouse experiment was conducted using a three-factor factorial design (four fertilizer sources, five application rates, and three soil textures) arranged in a randomized complete block design. ANOVA revealed significant effects of fertilizer source, application rate, soil texture, and significant two-way interactions between these factors. Polynomial contrasts of maize germination rates in response to increasing fertilizer doses allowed us to establish the maximum safe rates: i) DAP: 3 kg N ha-¹ in G1, 0.8 kg N ha-¹ in G2 and G3; ii) MAP: 5–7 kg N ha-¹ regardless of soil texture; iii) KCl: 10 kg K ha-¹ in G1, 14 kg K ha-¹ in G2 and G3; K2SO4: >16 kg K ha-¹ regardless of soil texture. The experiment also identified visual signs of toxicity, mainly associated with nitrogen fertilizers. These included delayed and reduced emergence, leaf chlorosis, necrotic roots and seeds, stunted and grooved coleoptiles, and, at high doses, seedling mortality. Other quantitative performance indicators, such as shoot and root biomass, chlorophyll readings, and early vigor, were strongly correlated with germination rates and supported the same conclusions regarding safe fertilizer rates. These findings provide practical recommendations for agronomists and farmers to optimize starter fertilizer management in maize by selecting appropriate application rates and fertilizer sources. |
| format | Article |
| id | doaj-art-5f677c63a23f46c3b2f307d260351d52 |
| institution | Kabale University |
| issn | 2673-3218 |
| language | English |
| publishDate | 2025-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Agronomy |
| spelling | doaj-art-5f677c63a23f46c3b2f307d260351d522025-08-20T03:44:01ZengFrontiers Media S.A.Frontiers in Agronomy2673-32182025-08-01710.3389/fagro.2025.15435641543564Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maizeWilliam Makaza0William Makaza1Lotfi Khiari2Lotfi Khiari3Mounir El Achaby4Center of Excellence in Soil and Fertilizer Research in Africa, College of Agriculture and Environmental Sciences, Mohammed VI Polytechnic University, Ben Guerir, MoroccoDepartment of Soils and Agri-Food Engineering, Faculty of Agricultural Sciences and Food, Laval University, Quebec, QC, CanadaCenter of Excellence in Soil and Fertilizer Research in Africa, College of Agriculture and Environmental Sciences, Mohammed VI Polytechnic University, Ben Guerir, MoroccoDepartment of Soils and Agri-Food Engineering, Faculty of Agricultural Sciences and Food, Laval University, Quebec, QC, CanadaMaterials Science, Energy and Nanoengineering Department (MSN), Mohammed VI Polytechnic University, Ben Guerir, MoroccoApplying starter nitrogen (N) and potassium (K) fertilizers in a pop-up placement directly in the maize seed furrow is a delicate practice due to the direct contact between fertilizers and seeds. This proximity increases the risk of seed damage caused by the salinity of N and K fertilizers and the ammoniacal toxicity of nitrogen fertilizers. This study aims to determine the safe application rates of four commonly used starter fertilizers: monoammonium phosphate (MAP: NH4H2PO4), diammonium phosphate (DAP: (NH4)2HPO4), potassium chloride (KCl), and potassium sulfate (K2SO4) across three soil textures: fine (G1), medium (G2), and coarse (G3). A greenhouse experiment was conducted using a three-factor factorial design (four fertilizer sources, five application rates, and three soil textures) arranged in a randomized complete block design. ANOVA revealed significant effects of fertilizer source, application rate, soil texture, and significant two-way interactions between these factors. Polynomial contrasts of maize germination rates in response to increasing fertilizer doses allowed us to establish the maximum safe rates: i) DAP: 3 kg N ha-¹ in G1, 0.8 kg N ha-¹ in G2 and G3; ii) MAP: 5–7 kg N ha-¹ regardless of soil texture; iii) KCl: 10 kg K ha-¹ in G1, 14 kg K ha-¹ in G2 and G3; K2SO4: >16 kg K ha-¹ regardless of soil texture. The experiment also identified visual signs of toxicity, mainly associated with nitrogen fertilizers. These included delayed and reduced emergence, leaf chlorosis, necrotic roots and seeds, stunted and grooved coleoptiles, and, at high doses, seedling mortality. Other quantitative performance indicators, such as shoot and root biomass, chlorophyll readings, and early vigor, were strongly correlated with germination rates and supported the same conclusions regarding safe fertilizer rates. These findings provide practical recommendations for agronomists and farmers to optimize starter fertilizer management in maize by selecting appropriate application rates and fertilizer sources.https://www.frontiersin.org/articles/10.3389/fagro.2025.1543564/fullfertilizer toxicityseed emergencesalt injuryNH3 toxicityin-furrow placementvisual toxicity signs |
| spellingShingle | William Makaza William Makaza Lotfi Khiari Lotfi Khiari Mounir El Achaby Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize Frontiers in Agronomy fertilizer toxicity seed emergence salt injury NH3 toxicity in-furrow placement visual toxicity signs |
| title | Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize |
| title_full | Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize |
| title_fullStr | Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize |
| title_full_unstemmed | Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize |
| title_short | Optimizing safe rates of pop-up inorganic starter nitrogen and potassium fertilizers for maize |
| title_sort | optimizing safe rates of pop up inorganic starter nitrogen and potassium fertilizers for maize |
| topic | fertilizer toxicity seed emergence salt injury NH3 toxicity in-furrow placement visual toxicity signs |
| url | https://www.frontiersin.org/articles/10.3389/fagro.2025.1543564/full |
| work_keys_str_mv | AT williammakaza optimizingsaferatesofpopupinorganicstarternitrogenandpotassiumfertilizersformaize AT williammakaza optimizingsaferatesofpopupinorganicstarternitrogenandpotassiumfertilizersformaize AT lotfikhiari optimizingsaferatesofpopupinorganicstarternitrogenandpotassiumfertilizersformaize AT lotfikhiari optimizingsaferatesofpopupinorganicstarternitrogenandpotassiumfertilizersformaize AT mounirelachaby optimizingsaferatesofpopupinorganicstarternitrogenandpotassiumfertilizersformaize |