Effect of liming using Lithothamnium calcareum on atrazine and S-metolachlor leaching and persistence in soil

Abstract

The objective of this study was to evaluate the effect of soil liming using Lithothamnium calcareum in comparison to dolomitic limestone and unlimed soil on leaching and persistence of atrazine and S-metolachlor herbicides in soil. The highest atrazine concentration was obtained between 0 and 20 cm in the unlimed soil, between 30 and 40 cm in the dolomitic limestone-treated soil, and between 10 and 20 cm in soil treated with L. calcareum. The highest S-metolachlor concentration was obtained between 20 and 30 cm in the unlimed soil, between 10 and 20 cm in the soil treated with dolomitic limestone, and between 0 and 10 cm in the soil treated with L. calcareum. The half-life of atrazine was 8.3 days in unlimed soil and 7.9 days in limed soil. The half-life of S-metolachlor was 12.1 days in unlimed soil, 13.5 days in soil using dolomitic limestone, and 11.6 days in soil using L. calcareum. Cucumber plants were controlled up to 90 days after application (DAA) of atrazine for all soil treatments. Sorghum plants were controlled up to 15 DAA of S-metolachlor for the unlimed soil and up to 30 DAA for the limed soil. Soil liming and type of soil improver influence atrazine e S-metolachlor leaching and persistence in soil, which may affect crops and adjacent areas and surface and groundwater.