Phosphorus and potassium effects on taproot C and N reserve pools and long-term persistence of alfalfa (Medicago sativa L.).

Autor: Berg WK; Advanced Agrilytics, 751 E 400 S., Huntington, IN, 46750, USA., Lissbrant S; Observatorio del Caribe Colombiano, Getsemaní, Calle del Guerrero #29-02, Cartagena de Indias, Colombia., Cunningham SM; Department of Agronomy, Purdue University, 915 West State St., West Lafayette, IN 47907-2054, USA., Brouder SM; Department of Agronomy, Purdue University, 915 West State St., West Lafayette, IN 47907-2054, USA., Volenec JJ; Department of Agronomy, Purdue University, 915 West State St., West Lafayette, IN 47907-2054, USA. Electronic address: jvolenec@purdue.edu.
Jazyk: angličtina
Zdroj: Plant science : an international journal of experimental plant biology [Plant Sci] 2018 Jul; Vol. 272, pp. 301-308. Date of Electronic Publication: 2018 Mar 15.
DOI: 10.1016/j.plantsci.2018.02.026
Abstrakt: Improved P and K nutrition can enhance yield and persistence of alfalfa (Medicago sativa L.) grown on low fertility soils, but it is unknown if the improved agronomic performance is associated with greater taproot N and C reserves. Our objective was to use cluster analysis to determine how alfalfa plant persistence is altered by P and K fertilization, and determine if changes in specific taproot C and/or N reserves were associated with alfalfa plant death. Taproots were dug and plants counted in May and December of each year and taproots analyzed for P, K, starch, sugar, amino-N, and soluble protein. K-means clustering was used to create six clusters that were subsequently compared using two-sample t-tests. Low K in herbage and taproots was associated with low yield and poor persistence of the Low and Very Low clusters and taproots of these plants generally had low starch, protein, and amino-N concentrations. Plants died primarily between May and December. Plant persistence of the low yielding, P-deficient Medium cluster was high and associated with high starch concentrations. Low amino-N concentrations in taproots may provide an early indication of potential plant death because these were evident in poor-persisting Low and Very Low clusters early in the study.
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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