P Malagoli1, P Laine, L Rossato, A Ourry. 1. UMR INRA-UCBN 950 EVA, Ecophysiologie Végétale, Agronomie et Nutritions N, C, S. Institut de Biologie Fondamentale et Appliquée, Université de Caen Basse Normandie, 14032 Caen Cedex, France.
Abstract
BACKGROUND AND AIMS: Oilseed rape (Brassica napus) has often been used as a catch crop to deal with the issue of N leaching, but for this to be effective, prediction of the crop's N uptake capability and N partitioning is required. The aim of this work was to build a compartmental model of N dynamics in oilseed rape, based on the kinetic description of N uptake, partitioning and mobilization in each organ. MODEL: In this study, logistic and exponential equations were fitted to the N relations of each compartment, especially the leaf at each node. Data previously obtained from an 15N-labelling field experiment was used to quantify the partitioning of total N content, the allocation of N taken up and subsequent changes in the sink/source status for endogenous N in each tissue throughout the growth cycle. KEY RESULTS AND CONCLUSIONS: This modelling approach provides a unique tool for the quantitative estimation of cycling of endogenous N in relation to changes in N uptake at the whole-plant level. Furthermore, as oilseed rape is known to release large amounts of N to the soil during spring through leaf loss, this model was used to identify potential methods for improving the N harvest index of the crop. Simulations showed that N content or yield could be improved by 15% by optimizing N transfer from vegetative to reproductive tissues and by reducing the residual %N (DW) in abscised leaves.
BACKGROUND AND AIMS: Oilseed rape (Brassica napus) has often been used as a catch crop to deal with the issue of N leaching, but for this to be effective, prediction of the crop's N uptake capability and N partitioning is required. The aim of this work was to build a compartmental model of N dynamics in oilseed rape, based on the kinetic description of N uptake, partitioning and mobilization in each organ. MODEL: In this study, logistic and exponential equations were fitted to the N relations of each compartment, especially the leaf at each node. Data previously obtained from an 15N-labelling field experiment was used to quantify the partitioning of total N content, the allocation of N taken up and subsequent changes in the sink/source status for endogenous N in each tissue throughout the growth cycle. KEY RESULTS AND CONCLUSIONS: This modelling approach provides a unique tool for the quantitative estimation of cycling of endogenous N in relation to changes in N uptake at the whole-plant level. Furthermore, as oilseed rape is known to release large amounts of N to the soil during spring through leaf loss, this model was used to identify potential methods for improving the N harvest index of the crop. Simulations showed that N content or yield could be improved by 15% by optimizing N transfer from vegetative to reproductive tissues and by reducing the residual %N (DW) in abscised leaves.
Authors: Suzanne Mickelson; Deven See; Fletcher D Meyer; John P Garner; Curt R Foster; Tom K Blake; Andreas M Fischer Journal: J Exp Bot Date: 2003-02 Impact factor: 6.992
Authors: Karen Massel; Bradley C Campbell; Emma S Mace; Shuaishuai Tai; Yongfu Tao; Belinda G Worland; David R Jordan; Jose R Botella; Ian D Godwin Journal: Front Plant Sci Date: 2016-10-25 Impact factor: 5.753