Imidazolinone leaching in response to different irrigation management on rice cultivated soil/Lixiviacao de imidazolinonas em resposta a diferentes manejos de irrigacao em solo de cultivo de arroz irrigado

• Published in: Ciência rural Vol. 44; no. 11; p. 1943
• Main Authors: Bundt, Angela Da Cas, de Avila, Luis Antonio, Agostinetto, Dirceu, Refatti, Joao Paulo, Cassol, Luciano, Rockemback, Fernanda Costa
• Format: Journal Article
• Language: Spanish
• Published: Universidade Federal de Santa Maria 01.11.2014
• Subjects: Herbicides; Leaching; Rice; Soil pollution
• ISSN: 0103-8478; 1678-4596
• DOI: 10.1590/0103-8478cr20131216

Herbicides used in Clearfield® rice system are characterized to be mobile in soil. This mobility contributes to environmental contamination and intensifies the residual in the soil, due to the upward movement during the off-season. The flooded irrigation used on rice crops is the main cause of imidazolinones leaching. However, alternative practices can be used to minimize leaching of herbicides. This research aimed to evaluate the effects of different irrigation management on leaching of imidazolinone herbicides. For this, two experiments were conducted using soil columns in a greenhouse and testing three irrigation managements: continuous, intermittent and field capacity. The herbicides were applied to soil surface and after 48 hours irrigation started. At 45 and 90 days of irrigation for the first and second trials, respectively, bioassay was carried out using different soil layers. Results showed that the formulated mixture of imazapyr + imazapic showed the greatest leaching potential. For individually herbicides tested, imazapic was the most leached one, followed by imazethapyr and imazapyr. Continuous and intermittent irrigation managements did not differ and promoted greater leaching potential of herbicides compared to soil at field capacity.