Navigating soil journey of atrazine: raveling leaching dynamics and crop response to dose variability
摘要
Atrazine is extensively applied as herbicide for effective weed control in maize, however its persistence and potential for leaching into groundwater pose soil, water and environmental risk. The current study aimed to evaluate leaching potential of atrazine through lysimeter filled with soil collected from MNS University of Agriculture, Multan, Pakistan. Moreover, we also assessed its dose response on six crops (maize, wheat, berseem, chickpea, mustard and oat) and weed (canary grass) by effective concentration 50. In lysimeter study, atrazine was applied at four levels having active ingredient 0.5x (312 g ha−1), 1.0x (625 g ha−1), 2.0x (1250 g ha−1) and 4.0x (2500 g ha−1) of the recommended dose. The highest residue concentration in leachate was 127 mg L−1 in response to 0.5 × dose at 15 days after application and 261.33 mg L−1 in response to 4.0 × dose after 30 days of application. In soil maximum residue concentration (1.53 mg kg−1) was observed at 75–90 cm depth for 4.0x, while minimum residue (0.012 mg kg−1) was determined in 0 − 15 cm layer of control. Values of the log Kd, Koc and groundwater ubiquity score ranged between 0.08–11.32, 30.76–1076.31, and 0.6–4.73 respectively. The dose response experiment identified that berseem and canary grass as most susceptible species indicating tolerance sequence of chickpea > wheat > mustard > oat > berseem > canary grass. These findings highlight the environmental implications of atrazine usage emphasizing that its application should be limited to recommended doses once a year to minimize risks of leaching and persistence in soil and groundwater.
Graphical abstract