Published October 7, 2016
| Version v1
Publication
Organic carbon, water repellency and soil stability to slaking under different crops and managements: a case study at aggregate and intra-aggregate scales
Description
This research studies the distribution of organic C and intensity of water repellency
in soil aggregates with different size and in the interior of aggregates from Mediterranean
soils under different crops (apricot, citrus and wheat) and management (con-
5 ventional tilling and no tilling/mulching). For this, undisturbed aggregates were sampled
and carefully divided in size fractions (0.25–0.5, 0.5–1, 1–2, 2–5, 5–10 and 10–15 mm)
or peeled to obtain separated aggregate layers (exterior, transitional and interior). Organic
C content in the fine earth fraction of soils under different crops did not show
important variations, although it increased significantly from conventionally tilled to
10 mulched soils. The distribution of organic C content in aggregates with different size
varied among soils under different crops, generally increasing with decreasing size.
At the intra-aggregate level, organic C concentrated preferably in the exterior layer of
aggregates from conventionally tilled soils, probably because of recent organic inputs
or leachates. In the case of mulched soils, higher concentrations were observed, but
15 no significant differences among aggregate regions were found. The intensity of water
repellency, determined by the ethanol method, did not show great variations among
crops, but increased significantly from conventionally tilled to mulched soils. Coarser
aggregates were generally wettable, while finer aggregates showed slight water repellency.
Regardless of variations in the distribution of organic C in aggregate layers from
20 conventionally tilled soils, great or significant differences in the distribution of water repellency
at the intra-aggregate level were not found in any case. Finally, the intensity of
water repellency was much more important than the concentration of organic C in the
stability to slaking of aggregates.
Abstract
Ministerio de Ciencia e Innovación CGL2010-21670-C02-01Abstract
Ministerio de Ciencia e Innovación CGL2012-38655-C04-01Additional details
Identifiers
- URL
- https://idus.us.es/handle/11441/47218
- URN
- urn:oai:idus.us.es:11441/47218