Data from: Rhizodeposition through root senescence and root exudation of atmospheric C and N by legumes is controlled by traits indicative of resource acquisition and root development

Legume crop production has many benefits for agricultural systems. Through
the rhizodeposition process, they release a significant amount of C and N
into the soil, increasing soil organic C and reducing the use of N
fertilizer. Rhizodeposition is known as a dynamic process influenced by
many factors. The aim of this study was to study the contribution of root
exudation and root senescence to the rhizodeposition of atmospheric C and
N during vegetative and reproductive growth in annual and perennial
legumes and to understand how this is linked to the fixation capacities of
C and N and root functional traits. An original approach that combined
13CO2 labeling and the 15N dilution method was developed to measure the
rhizodeposition of atmospheric C and N throughout plant growth by two
annual grain legumes (pea and faba bean) and two perennial forage legumes
(white and crimson clovers). C rhizodeposition was found to increase
proportionally with N rhizodeposition during reproductive development and
the differences observed between species were related to the C and N
fixation abilities. The use of root traits such as specific root length,
root tissue density, and root dry matter content suggests a strong
contribution of root exudation to C rhizodeposition at vegetative growth
and a strong contribution of root senescence to both C and N
rhizodeposition during reproductive growth. Synthesis: Both C and
N rhizodeposition appeared to be controlled by traits indicative of
resource acquisition and root development.