The Role of Sugarcane Residues in the Sorption and Leaching of Herbicides in Two Tropical Soils

Author(s)

Giori, Fabricio Garcia ^[1] ; Tornisielo, Valdemar Luiz ^[2] ; Regitano, Jussara Borges ^[1]

Affiliation

^[1] Univ Sao Paulo ESALQ USP, Coll Agr Luiz de Queiroz, Dept Soil Sci, BR-13418900 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo CENA USP, Ctr Nucl Energy Agr, Ecotoxicol Lab, BR-13400970 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: WATER AIR AND SOIL POLLUTION; v. 225, n. 4 APR 2014.
• Web of Science Citations: 14

Abstract

Sugarcane is a major crop in Brazil that generates huge amounts of organic residues that are usually left deposited in, or applied to the soil, and thereby affect the behavior of herbicides. This study assessed the effects of sugarcane residues (straw, ash, and compost) and residence time ({''}aging{''}) on the sorption of alachlor and diuron in two contrasting soils (LVd and LVAd), as well as the effects of these residues on the leaching of alachlor. Adding straw and compost had no effect, whereas adding ash significantly increased sorption of both herbicides. Aging (28 days) increased apparent sorption distribution coefficients (K-d,(app) values) by 1.2 to 2.3 times. Straw and ash amendments resulted in less leaching of alachlor (<1.0% of the applied amount) than compost or control soil (similar to 6 % of the applied amount). The straw retained similar to 80 % of the applied alachlor may during leaching. Although this may be overrated due to an artifact of the methodology adopted, alachlor retention in the straw could not be predicted by the use of K-d,K-app. The transport potential of alachl o rmay be overestimated if aging and sugarcane straw management are not factored into the models. (AU)

• FAPESP's process: 12/15843-0 - Harvesting systems (with and without residue burning) on the sorption and desorption of herbicides in sugar cane
• Grantee: Jussara Borges Regitano
• Support Opportunities: Regular Research Grants