Details

Autor(en) / Beteiligte

• Stewart, Catherine E
• Moturi, Pratibha
• Follett, Ronald F
• Halvorson, Ardell D

Titel

Lignin biochemistry and soil N determine crop residue decomposition and soil priming

Ist Teil von

• Biogeochemistry, 2015-05, Vol.124 (1-3), p.335-351

Ort / Verlag

Cham: Springer-Verlag

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Residue lignin content and biochemistry are important properties influencing residue decomposition dynamics and native soil C loss through priming. The relative contribution of high lignin residues to soil organic matter (SOM) may be less than previously believed, be more sensitive to soil N status, and may be more sensitive to increased temperature. We examined the role of residue biochemistry, temperature, and soil N on the decomposition dynamics of five crop residues varying in lignin content and composition (corn, sorghum, soybean, sunflower and wheat). We used natural abundance δ¹³CO₂to quantify residue decomposition and soil priming from a soil previously cropped to wheat-fallow or to corn-millet-wheat at 20 and 30 °C in a laboratory incubation. High lignin residues decomposed more completely than low lignin residues, supporting a new model of SOM formation suggesting high lignin residues have a lower efficiency for stabilizing SOM due to inefficient microbial processing. However, residues with lower residue respiration had greater soil C respiration (soil priming). Residue SG lignin was positively related to residue C respired and H-lignin positively related to soil C respired in all soils and temperatures, resulting in no net lignin chemistry effect on the combined total C respired. Effects of lignin on residue decomposition were most apparent in treatments with lower soil N contents indicating N limitation. Measuring both residue and soil respiration and considering soil N status is important to accurately assess the effects of residue biochemistry on soil organic carbon.