Nitrogen use efficiency in rapeseed. A review

Abstract

Mineral nitrogen fertilization has improved crop yield over the last century but has also caused air and water pollution. Reduction of nitrogen inputs and maintaining high yields are therefore essential to ensure a more sustainable agriculture. Improving the nitrogen use efficiency (NUE) of crops is therefore needed. Rapeseed, Brassica napus, depends on nitrogen fertilization due to its low NUE, with the ratio of plant nitrogen content to nitrogen supplied often not exceeding 60 %. Here, we review the major phenotypic traits associated with NUE in B. napus, with special emphasis on winter oilseed rape. We discuss the genetic diversity available and potential breeding strategies. The major points are the following: (1) rapeseed seed yield elaboration is complex, with overlapping phases of nitrogen uptake and remobilization during the crop cycle; (2) traits related to nitrogen uptake, such as root length and the amount of nitrogen absorbed after flowering, and traits related to nitrogen remobilization, such as the "staygreen" phenotype, have been identified as possible levers to improve NUE in rapeseed; (3) a substantial body of studies investigating the genetic control of NUE traits have already published and potential candidate genes identified; and (4) rapeseed genetic diversity may be enriched by exploiting interpopulation genetic variation and the closely related gene pools of Brassica rapa and Brassica oleracea.

Greenhouse gas emissions from the energy crop oilseed rape (Brassica napus); the role of photosynthetically active radiation in diurnal N2O flux variation

“…Nitrogen uptake efficiency is a problem in OSR, where it is as low as 50% (Bouchet et al, 2016) and our findings underline this inefficiency. Nitrogen uptake efficiency is a problem in OSR, where it is as low as 50% (Bouchet et al, 2016) and our findings underline this inefficiency.…”

“…The high N 2 O emissions across all treatments, even at 50% of the management applied N rate, demonstrate how important this gas is for crop GHG balance. Nitrogen uptake efficiency is a problem in OSR, where it is as low as 50% (Bouchet et al, 2016) and our findings underline this inefficiency. We suggest that as the management fertilizer rate, which received double the N of the NH 4 treatment, either increased crop biomass, N content (unpublished data) or N 2 O emissions that fertilizer is lost through immobilization or leaching, as outlined in Bouchet et al (2016).…”

“…Nitrogen uptake efficiency is a problem in OSR, where it is as low as 50% (Bouchet et al, 2016) and our findings underline this inefficiency. We suggest that as the management fertilizer rate, which received double the N of the NH 4 treatment, either increased crop biomass, N content (unpublished data) or N 2 O emissions that fertilizer is lost through immobilization or leaching, as outlined in Bouchet et al (2016). We have shown that PAR, probably by supplying labile C to facilitate denitrification, is a strong driver of N 2 O emissions, and its inclusion in GHG flux models should improve model accuracy, a vital tool to mitigate climate change.…”

Comparative genome and transcriptome analysis unravels key factors of nitrogen use efficiency in Brassica napus L

“…However, as for all non‐legume crops, N is a key limiting macronutrient in oilseed rape production and has to be fertilized in high quantities for sufficient productivity (Wang et al, ). Despite a considerable capacity for N uptake, oilseed rape is often described as a crop with poor N‐efficiency and low seed production per unit N applied (Bouchet et al, ). However, recent studies have shown considerable strategies to improve agronomic NUE in oilseed rape include intensive crop management (Liu et al, ), more accurate prediction of N requirement (Henke, Breustedt, Sieling, & Kage, ), more precise application of N fertilizers (Nkebiwe, Weinmann, Bar‐Tal, & Muller, ), and the development of better genotypes (He et al, ; Salisbury, Cowling, & Potter, ; Stahl, Pfeifer, Frisch, Wittkop, & Snowdon, ).…”

Do farmers in Germany exploit the potential yield and nitrogen benefits from preceding oilseed rape in winter wheat cultivation?

“…Another factor is the high N surplus after OSR, which can exceed 40% of applied N (Henke et al 2008;Bouchet et al 2016). To avoid negative environmental and economic impacts, regional N fertiliser recommendations take into account an 'N credit' of 10-20 kg N ha −1 from the previous OSR crop (Wendland et al 2012;DLR 2016).…”