Can cell wall network explain crop residue decomposition and soil organic matter dynamic? A new insight into residue quality

摘要

This study aimed at determining the chemical characteristics of roots that regulate their C mineralization on the long term in soil. The chemical composition of maize roots from sixteen genotypes was characterized in details before soil decomposition.Roots were also incubated in soil for 796 days under laboratory conditions (15°C, -80 kPa). The chemical quality of maize roots differed markedly between genotypes notably in term of cell wall polysaccharides contents and quality, lignins contents andquality and esterified phenolic acids contents. Statistical relationships were established between the fate of C from roots and their initial chemical characteristics. The role of the intimate associations between the lignin fraction and cell wall polysaccharides in a cohesive network, and the role of esterified PCA as one of the main interconnecting agents between polymers in graminaceous cell walls, are of primary importance and could improve the prediction of residue decomposition in soils.