Chemical and biological properties as affected by glyphosate and zinc application in soybean plants

Abstract

Soil management practices with herbicide and fertilizers application may change the soil properties. The amplitude of the change varies according to the soil property and management system. The aim of this study was to evaluate the effects of glyphosate and zinc on the chemical and biological properties in two soil types (Typic Hapludox [TH] and Ustoxix Quartzipsamment [UQ]). Two soybean cultivars (conventional BRS 133 and its essentially derived transgenic line, BRS 245RR, with and without glyphosate application) and five Zn rates (0, 5, 10, 20, and 40 mg kg − 1) with four replicates were studied. Nodule dry weight (NDW), microbial biomass carbon (MBC), and soil chemical attributes were evaluated. Glyphosate application resulted in differences in MBC between the two soils types with a significant cultivar × Zn rate interaction, while NDW revealed the effects of Zn rates and cultivars under TH, and Zn rates under UQ. The cultivars and the Zn rates did not influence any of the soil chemical attributes, excluding available Zn. Mehlich 1 and DTPA-TEA extractants were effective for the determination of available Zn in the soil.

Keywords:

• glycine max
• herbicide
• microbial biomass carbon
• nodule dry weight
• soil chemical properties
• transgenic

Acknowledgments

We are grateful to the Soil and Plant Mineral Nutrition Staff of Embrapa Pecuária Sudeste (CPPSE) for assistance with the analysis of soil chemical and biological attributes.