Abstract
Field trials were conducted with two nitrogen applications (0 or 240 kg N ha−1) and three modern cultivars of winter oilseed rape (Brassica napus L.) previously selected from a root morphology screen at a young developmental stage. The purpose is to examine the relationship between root morphology and Nitrogen Uptake Efficiency (NUpE) and to test the predictiveness of some canopy optical indices for seed quality and yield. A tube-rhizotron system was used to incorporate below-ground root growth information. Practically, clear tubes of one meter in length were installed in soil at an angle of 45°. The root development was followed with a camera at key growth stages in autumn (leaf development) and spring (stem elongation and flowering). Autumn was a critical time window to observe the root development, and exploration in deeper horizons (36–48 cm) was faster without any fertilization treatment. Analysis of the rhizotron images was challenging and it was not possible to clearly discriminate between cultivars. Canopy reflectance and leaf optical indices were measured with proximal sensors. The Normalized Difference Vegetation Index (NDVI) was a positive indicator of biomass and seed yield while the Nitrogen Balance Index (NBI) was a positive indicator of above-ground biomass N concentration at flowering and seed N concentration at harvest.
Highlights
By the year 2050, a societal challenge will be to almost double the food production from existing land areas to feed more than an estimated nine billion people [1,2]
The three varieties of winter oilseed rape (Brassica napus L.) are restored hybrids registered in the French catalogue of plant species and varieties with the following names: DK Exception (DKE), DK Expansion (DKA), and Dualis (DUA)
Seeds were obtained from the Terres Inovia network for post-registration evaluation of winter oilseed rape cultivars in Northern France
Summary
By the year 2050, a societal challenge will be to almost double the food production from existing land areas to feed more than an estimated nine billion people [1,2]. Innovation has to make a step change to achieve environmentally sustainable intensification of agricultural systems. Crop production heavily relies on chemical fertilizers, but a considerable fraction of these gets lost with harmful consequences to the environment. Nitrogen (N) is the macronutrient required in the largest amount by crops. N is continually depleted by such processes as exportation of N-containing crop residues, ammonia volatilization, microbial denitrification, erosion or. The soil N reserve must be replenished every so often to sustain crop yield but
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
