2024-03-29T15:41:49Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1229942018-01-31T05:31:23Zcom_10261_75com_10261_6col_10261_328
Soil organic matter fractions as affected by tillage and soil texture under semiarid Mediterranean conditions
Blanco-Moure, Nuria
Gracia Ballarín, Ricardo
Bielsa Aced, Ana
López Sánchez, María Victoria
Comisión Interministerial de Ciencia y Tecnología, CICYT (España)
European Commission
Soil organic carbon
Particulate organic matter
Mineral-associated organic matter
Conservation tillage
Rainfed agriculture
37 Pags.- 6 Tabls.- 3 Figs. The definitive version is available at: http://www.sciencedirect.com/science/journal/01671987
The inherent complexity of soil organic matter (SOM) and its stabilization processes make suitable the identification of SOM fractions that reflect the management-induced changes in soil organic carbon (SOC) dynamics. This is of special interest in semiarid regions where the capacity of soil for agricultural production is limited. This study aims to evaluate the effect of different tillage and soil management practices on the distribution of C among SOM fractions and determine the influence of soil texture on the protection of SOC in a semiarid Mediterranean region (Aragon, NE Spain). Under on-farm conditions, pairs of adjacent fields under long-term no tillage (NT) and conventional tillage (CT) were compared in five different cereal production areas. In all cases, a nearby undisturbed soil under native vegetation (NAT) was included. Results indicate that the two isolated mineral-associated OM (Min) fractions, d-Min and μagg-Min (outside and within stable microaggregates, respectively), constituted the main part of total SOC (mean contributions of 54 and 26%, respectively) and were not consistently affected by soil management. Soil clay was a determinant factor for d-Min-C and total SOC (r2 = 0.60–0.70; P < 0.001), indicating that chemical stabilization, through clay–organic complexes, seems to be a main preservation mechanism in the studied soils. Physical protection seems to be another SOC stabilization process in these soils due to strong correlation found between μagg-Min-C and the mass of water-stable microaggregates (r = 0.900; P < 0.0001). With smaller contributions to total SOC, the two labile fractions, coarse and fine particulate OM (cPOM and fPOM) were sensitive to soil management and their concentrations decreased as soil disturbance increased (NAT > NT > CT). The highest differences between NT and CT corresponded to fPOM at the soil surface where this fraction was 1.2–3 times higher under NT. Higher soil stratification ratios in NT, always >2 for the POM fractions, indicate an improvement in soil quality with long-term NT adoption in this semiarid Mediterranean region.
2015-10-05T10:10:45Z
2015-10-05T10:10:45Z
2016-01
artículo
Blanco-Moure N, Gracia R, Bielsa AC, López MV. Soil organic matter fractions as affected by tillage and soil texture under semiarid Mediterranean conditions. Soil and Tillage Research 155: 381–389 (2016)
0167-1987
http://hdl.handle.net/10261/122994
10.1016/j.still.2015.08.011
http://dx.doi.org/10.13039/501100007273
http://dx.doi.org/10.13039/501100000780
eng
Postprint
http://dx.doi.org/10.1016/j.still.2015.08.011
Sí
http://creativecommons.org/licenses/by-nc-nd/4.0/
openAccess
Elsevier