TY - JOUR
T1 - Insufficient nitrogen supply from symbiotic fixation reduces seasonal crop growth and nitrogen mobilization to seed in highly productive soybean crops
AU - Cafaro La Menza, Nicolas
AU - Monzon, Juan Pablo
AU - Lindquist, John L.
AU - Arkebauer, Timothy J.
AU - Knops, Johannes M.H.
AU - Unkovich, Murray
AU - Specht, James E.
AU - Grassini, Patricio
N1 - Funding Information:
This project was supported by the Nebraska Soybean Board. We acknowledge David Scoby and Aaron Hoagland at University of Nebraska‐Lincoln (UNL) and Keith Glewen, Jennifer Rees, Todd Whitney, and Amy Timmerman (UNL Extension) for their technical assistance. We also thank Juan Pedro Erasun, Ana Carolina Duarte Rabelo, Mariano Hernandez, and Agustina Diale for their assistance with field sampling and laboratory measurements. Finally, we are grateful to four farmers in Nebraska that kindly give us access to their fields to conduct the experiments.
Funding Information:
This project was supported by the Nebraska Soybean Board. We acknowledge David Scoby and Aaron Hoagland at University of Nebraska-Lincoln (UNL) and Keith Glewen, Jennifer Rees, Todd Whitney, and Amy Timmerman (UNL Extension) for their technical assistance. We also thank Juan Pedro Erasun, Ana Carolina Duarte Rabelo, Mariano Hernandez, and Agustina Diale for their assistance with field sampling and laboratory measurements. Finally, we are grateful to four farmers in Nebraska that kindly give us access to their fields to conduct the experiments.
Publisher Copyright:
© 2020 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - 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 N2 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 N2 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 N2 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.
AB - 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 N2 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 N2 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 N2 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.
KW - Glycine max (L.) Merr.
KW - leaf area
KW - nitrogen
KW - soybean
KW - symbiotic fixation
UR - http://www.scopus.com/inward/record.url?scp=85086277376&partnerID=8YFLogxK
U2 - 10.1111/pce.13804
DO - 10.1111/pce.13804
M3 - Article
C2 - 32430922
AN - SCOPUS:85086277376
SN - 0140-7791
VL - 43
SP - 1958
EP - 1972
JO - Plant Cell and Environment
JF - Plant Cell and Environment
IS - 8
ER -