Insufficient nitrogen supply from symbiotic fixation reduces seasonal crop growth and nitrogen mobilization to seed in highly productive soybean crops.

Autor: Cafaro La Menza N; Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA., Monzon JP; Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.; National Scientific and Technical Research Council (CONICET), Balcarce, Argentina., Lindquist JL; Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA., Arkebauer TJ; Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA., Knops JMH; School of Biological Science, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.; Department of Health and Environmental Science, Xi'an Jiaotong Liverpool University, Suzhou, China., Unkovich M; School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, South Australia, Australia., Specht JE; Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA., Grassini P; Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2020 Aug; Vol. 43 (8), pp. 1958-1972. Date of Electronic Publication: 2020 Jun 12.
DOI: 10.1111/pce.13804
Abstrakt: Nitrogen (N) supply can limit the yields of soybean [Glycine max (L.) Merr.] in highly productive environments. To explore the physiological mechanisms underlying this limitation, seasonal changes in N dynamics, aboveground dry matter (ADM) accumulation, leaf area index (LAI) and fraction of absorbed radiation (fAPAR) were compared in crops relying only on biological N 2 fixation and available soil N (zero-N treatment) versus crops receiving N fertilizer (full-N treatment). Experiments were conducted in seven high-yield environments without water limitation, where crops received optimal management. In the zero-N treatment, biological N 2 fixation was not sufficient to meet the N demand of the growing crop from early in the season up to beginning of seed filling. As a result, crop LAI, growth, N accumulation, radiation-use efficiency and fAPAR were consistently higher in the full-N than in the zero-N treatment, leading to improved seed set and yield. Similarly, plants in the full-N treatment had heavier seeds with higher N concentration because of greater N mobilization from vegetative organs to seeds. Future yield gains in high-yield soybean production systems will require an increase in biological N 2 fixation, greater supply of N from soil or fertilizer, or alleviation of the trade-off between these two sources of N in order to meet the plant demand.
(© 2020 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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