Leaching potential of herbicides used in cotton crop under soil column conditions

Planta Daninha

Inoue, M.H¹  Clemente, R.A¹  Pereira, K.M¹  Oliveira Jr, R.S¹  Possamai, A.C.S¹  Santana, D.C¹  Universidade do Estado de Mato Grosso, Tangará da Serra¹  Universidade Estadual Paulista Júlio de Mesquita Filho, Botucatu¹  Universidade Estadual de Maringá, Maringá¹  Dallacort, R¹  Santana, C.T.C¹ 

关键词: groundwater;    bio-indicator;    contamination;    environmental impact;    texture.;   

DOI  :  10.1590/S0100-83582010000400016

学科分类：农业科学（综合）

来源: Sociedade Brasileira da Ciencia das Plantas Daninhas (S B C P D) / Brazilian Society of Herb Science

【 摘 要 】

Herbicide use intensification implies in the need to determine the potential of these substances to reach groundwater. Thus, this study aimed to evaluate the influence of different irrigation depths on the leaching potential of four herbicides commonly used in preemergence cotton weed control, in samples of two soils from Campo Novo do Parecis-MT (RQ-sandy texture) and Tangará da Serra-MT (LV-clay texture). Thus, a bioassay technique in soil columns was adopted, in which water depths of 0, 20, 40, 60, 80 and 100 mm were simulated after application of alachlor (RQ 2.40; LV 3.36 kg ha-1), oxyfluorfen (RQ 0.48; LV 0.72 kg ha-1), prometryne (RQ 0.75; LV 1.50 kg ha-1) and S-metolachlor (RQ 1.20; LV 1.44 kg ha-1). For soil samples with sandy texture (RQ), water depths of 80 and 100 mm led to leaching down to layers of 10-15 cm for alachlor and 15-20 cm for S-metolachlor.Regardless of the irrigation depth applied in the RQ samples, oxyfluorfen did not exceed the depth of 5-10 cm and prometryne could be detected at the depth of 10-15 cm only at water depth of 100 mm. In columns filled with clay soil (LV), oxyfluorfen did not move beneath the surface layer, even under the highest water depths and prometryne reached the depth of 5-10 cm under 80 and 100 mm. The herbicides alachlor and S-metolachlor reached 10-15 cm depth under water depths of 80 and 100 mm in the LV. A more intense downward movement of the herbicide molecules was found in sandy soil samples (RQ) than in clay texture soil samples (LV).

【 授权许可】

Unknown