Assessment of runoff using ⁷Be in vineyards in the central valley of Chile

ABSTRACT

In Chile, erosion processes (on-site and off-site impact) affect at least 36.9 million ha^–1, representing 49% of the total land area. Different regions show severe soil degradation mainly caused by water erosion processes. The importance of sediment-associated transport and the key role of soil erosion affect the fertility of the land and the contamination of water bodies. The aim of this work was to estimate the erosion rate, caused by the rainfall in Apalta vineyards in the Libertador General Bernardo O'Higgins Region of Chile using isotope techniques, assessing the ⁷Be runoff during four years (2009–2012). The ⁷Be distribution mass depth at a reference site ranged from 7 to 24 kg m^–2 in the first two centimetres soil layer. Even when the vineyards have been well managed, the topographic characteristics and the climatic conditions facilitated soil erosion, with average rates of 50.4, 23.5, 50.6 and 67.3 tons ha^–1 y^–1 in 2009, 2010, 2011 and 2012, respectively. The robustness of the ⁷Be technique demonstrated the advantage of a non-soil-destructive methodology to calculate soil distribution and erosion rates.

KEYWORDS:

• Agriculture
• beryllium-7
• Chile
• isotope techniques
• radioactive isotopes
• soil erosion

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the International Atomic Energy Agency (IAEA) under Grant CHI 5048 (Integrated Watershed Management for the Sustainability of Agricultural Lands).