INVESTIGADORES
RUBIO Gerardo
artículos
Título:
Cover crop effects on soybean residue decomposition and P release in no-tillage systems of Argentina. Soil & Tillage Research
Autor/es:
VARELA, MF,; C M SCIANCA ;; MA TABOADA; G RUBIO.
Revista:
SOIL & TILLAGE RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2014 vol. 143 p. 59 - 66
ISSN:
0167-1987
Resumen:
Cover crops (CC) provide many benefits to soils but their effect on decomposition of previous crop residues and release of nutrients in continuous no-tillage soybean [Glycine max (L.) Merr.]  production are little known. Our objective was to quantify CC effects on decomposition and phosphorus (P) release from soybean residue using litterbags. Three CC species (oat, Avena sativa L; rye, Secale cereal L; and rye grass, Lolium multiflorum L) and a no CC control were evaluated. Temperature, moisture content, microbial biomass and microbial activity were measured in the surface 2 cm of soil and residues. Cover crops increased soybean residue decomposition slightly both years (8.2 and 6.4%). Phosphorus release from soybean residue did not show any significant differences. Cover crops increased microbial biomass quantity and activity in both soil and residue samples (p<0.001,p=0.049 for soil and residue microbial biomass; p=0.060, p=0.003 for soil and residue microbial activity, respectively). Increased residue decomposition with CC was associated with higher soil and residue microbial biomass and activity, higher near-surface (0 to 2 cm) moisture content (due to shading) and soil organic carbon enrichment by CC. Even though CC increased soybean residue decomposition (233 kg ha-1), this effect was compensated for by the annual addition of approximately 6500 kg ha-1 of CC biomass. This study demonstrated another role for CC when calibrating models that simulate the decomposition of residues in no-tillage systems.   Key words Soybean residues; phosphorus; nutrient cycling; soil organic carbon