Can edaphic variables improve DTPA-Based zinc diagnosis in corn?
Current zinc (Zn) diagnostic methods for corn (Zea mays L.) are often based on soil DTPA (diethylenetriamine-pentaacetic acid) extractable Zn (DTPA-Zn). However, calibration of the DTPA-Zn test may be influenced by other soil properties such as pH, organic matter (SOM) and available Bray-P (PBray-1)...
| Autores principales: | , , , , , , , , , , |
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| Formato: | info:ar-repo/semantics/artículo |
| Lenguaje: | Inglés |
| Publicado: |
2017
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| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12123/618 https://acsess.onlinelibrary.wiley.com/doi/10.2136/sssaj2016.09.0316 https://doi.org/10.2136/sssaj2016.09.0316 |
| Sumario: | Current zinc (Zn) diagnostic methods for corn (Zea mays L.) are often based on soil DTPA (diethylenetriamine-pentaacetic acid) extractable Zn (DTPA-Zn). However, calibration of the DTPA-Zn test may be influenced by other soil properties such as pH, organic matter (SOM) and available Bray-P (PBray-1). Our objective was to assess the contribution of soil properties to a DTPA-Zn model used to predict corn response to Zn fertilization. We conducted 64 field trials with two Zn-fertilization treatments: with and without Zn fertilization. In all sites, we measured SOM, PBray-1, pH, and DTPA-Zn at 0- to 20-cm depth before sowing. Yield difference between Zn-fertilized and unfertilized treatments (Ydifference) was significant in 33% of the experimental site-years. In responsive site-years, the average Ydifference was 0.98 Mg ha-1 (11.4%). Soil organic matter was the only property that was a significant addition to the DTPA-Zn model for predicting the corn relative yield (Model R2 including SOM = 0.27). However, the improvement was nominal (Partial R2 of SOM = 0.06). Use of DTPA-Zn alone was suitable to discriminate Zn responsiveness among site-years based on the Ydifference by correctly diagnosing 81% of the outcomes. We determined three soil DPTA-Zn ranges with different probability of resulting in a Ydifference greater than zero when fertilized with Zn: high (<0.9 mg kg-1), medium (0.9–1.3 mg kg-1), and low (>1.3 mg kg-1). These soil-test-based Zn recommendations improve the identification of Zn-deficient soils allowing prevention of yield loss from Zn deficiency and more rational use of Zn fertilizers. |
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